# Solar generator battery questions



## Jackal01

Greetings. I searched a bit on here and couldn't find the answers nor on Google. Probably because I am not wording it correctly. I search beforeI post threads (I'm a mod on JeepForum and gripe regularly about newbs not searching first :laugh: )

I am wanting to build my own solar generator for camping and during a power outage to run a couple oscillating fans, LED TV, some CFL/LED lights, possibly a full size fridge, laptops, cell phones for an outage and just a handful of lights for the camping part. I read several websites and watched some YT videos regarding solar generators. My question is how do I determine what the wattage capacity will be with the components listed below. This is to determine what I will be able to run ie: adding up the wattage of each device and seeing if a gasoline generator can power said devices. I just do not know how to determine that figure with a solar generator.

-Die Hard Marine battery: 12v 115 amp hour at 20 hours. (will use two of these)
-Whistler 2000w inverter
-2 Renogy 100 Watt Monocrystalline Solar Panels (200 watts total) with 30a charger controller

I would like to be able to charge the batteries while driving, too. We go to the San Juans in CO every couple years to backpack and ride the Jeep trails so charging it on the road is a plus. I saw a video on youtube of a guy that wired a female DC plug to the box (that the batteries and inverter are in) and had his solar panels wired to a male DC plug and then had an extension cord with double males to plug each end into the box and the vehicle. I am not sure how he accomplished that or if it is even possible to properly charge the batteries. I know basic electrical wiring type stuff but when it comes to the nitty gritty of electrical "engineering" and whatnot...I get lost quickly. I am trying to teach myself with this setup.

Many thanks.


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## rwrice

You need to determine how much power your gear will consume. Get yourself a kill-a-watt and run each one for a full day. It will record the total power for that time frame needed. Carefully consider what you want to run after you know it's requirements. Once you know how much battery capacity you need then you can calculate the solar panel size.


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## cowboyhermit

rwrice is correct, however given a set of components there are some ways to determine the capacity.

First of all those batteries will have a combined 130Ah @12V=1560 Wh
This means that you could run something 1500W (maximum for most household plugs) for 1 hour. Or any division there of such as 100W for 15 hours. As mentioned below the batteries would have 230Ah=2760Wh, what was I thinking?
This is theoretical however, if it is not for emergency use you do not want to drain the batteries completely, plus the Inverter is not 100% efficient. 1000Wh would be a safe bet.

Then you can figure the panels, it would take 200W of solar about 8 hours of sun to charge those batteries from dead, about 6 hours from 1000Wh level. If you have more than this you will have added capacity.

With regards to charging from a vehicle, this is fine as long as you don't overload your alternator. I would recommend the heavy duty Anderson connectors on the battery bank and install one on your vehicle but they aren't cheap and other ways will work as well.

With regards to what you can run, it depends on the appliances but as a general guide this system would properly handle one efficient fridge. Or all that other stuff, both would be a stretch without other power from a vehicle or such.


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## Jackal01

cowboyhermit said:


> rwrice is correct, however given a set of components there are some ways to determine the capacity.
> 
> First of all those batteries will have a combined 130Ah @12V=1560 Wh
> This means that you could run something 1500W (maximum for most household plugs) for 1 hour. Or any division there of such as 100W for 15 hours.
> This is theoretical however, if it is not for emergency use you do not want to drain the batteries completely, plus the Inverter is not 100% efficient. 1000Wh would be a safe bet.
> 
> Then you can figure the panels, it would take 200W of solar about 8 hours of sun to charge those batteries from dead, about 6 hours from 1000Wh level. If you have more than this you will have added capacity.
> 
> With regards to charging from a vehicle, this is fine as long as you don't overload your alternator. I would recommend the heavy duty Anderson connectors on the battery bank and install one on your vehicle but they aren't cheap and other ways will work as well.
> 
> With regards to what you can run, it depends on the appliances but as a general guide this system would properly handle one efficient fridge. Or all that other stuff, both would be a stretch without other power from a vehicle or such.


I think I understand. I think.

Now, you said 130Ah for both batteries. Why is it not 230 Ah since each battery is 115A? Not that the figure really matters I just want to double check for knowledge sake.

I understand the part about figuring out the wattage of each device. I haven't added them up as of yet so my list of devices was just as a FYI to see what my use will be not so much asking if my proposed generator will power said devices. So am I correct to assume, based off of what you said, that for all intents and purposes this generator can provide 1500 watts of power? I know this is a subjective question but I will ask it anyway, does this look like it would be a good system (ie the components look to be of good quality, it will last a while, etc). I know Die Hard is good. I don't know anything about Whistler or the panels.


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## cowboyhermit

Jackal01 said:


> I think I understand. I think.
> 
> Now, you said 130Ah for both batteries. Why is it not 230 Ah since each battery is 115A? Not that the figure really matters I just want to double check for knowledge sake.
> 
> I understand the part about figuring out the wattage of each device. I haven't added them up as of yet so my list of devices was just as a FYI to see what my use will be not so much asking if my proposed generator will power said devices. So am I correct to assume, based off of what you said, that for all intents and purposes this generator can provide 1500 watts of power? I know this is a subjective question but I will ask it anyway, does this look like it would be a good system (ie the components look to be of good quality, it will last a while, etc). I know Die Hard is good. I don't know anything about Whistler or the panels.


:doh: Because I am distracted and made a mistake I should have realized that was too low.
I have trouble seeing these things in terms of a generator. If the only source of power is 200W solar over say 8 hours, then I guess it could be considered a 1500W generator for an hour of runtime :dunno:


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## labotomi

Just an aside:
The amp-hour capacity is set at a specific rate. That capacity will be different at rates other than the one listed.

EG. 115 AH at the 20 hour rate 
You can run a 5.75amp load for 20 hours (5.75amps * 20hours = 115 amp-hours)
If you ran twice the amperage you would not get 115AH out of the battery 11.5 amps * 10 hours (115AH)... you would get quite a bit less such as 7 hours or 80.5AH (just a guess). Also if you were to run a smaller load you could get more amp-hours from the battery such as 4 amps for 35 hours or 140AH (another guess).

The values can be calculated if you wanted but not many go through the trouble.


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## Jackal01

cowboyhermit said:


> :doh: Because I am distracted and made a mistake I should have realized that was too low.
> I have trouble seeing these things in terms of a generator. If the only source of power is 200W solar over say 8 hours, then I guess it could be considered a 1500W generator for an hour of runtime :dunno:


Now I am a little more confused. Maybe. It seems like a good setup so far to me.


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## Caribou

This is going to be a mobile rig so you might want to factor in other considerations. Will you want to park in the shade to keep your rig cool? This will reduce the production of electricity. A less than optimal angle on the sun will likewise reduce production. 

I lived on a battery system for two years. My answer was as large a battery bank as space and weight would allow. I also separated my batteries into an engine battery and a house battery bank. It would have been a real bummer to not be able to start the engine to charge the house batteries or to travel.

You can get controllers that have multiple inputs so using solar and your alternator are not a problem.


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## LincTex

Jackal01 said:


> Greetings. I searched a bit on here and couldn't find the answers .... I am wanting to build my own solar generator for camping and during a power outage to run a couple oscillating fans, LED TV, some CFL/LED lights, possibly a full size fridge, laptops, cell phones for an outage and just a handful of lights for the camping part.


I thought this was made "sticky" but I guess it wasn't:

http://www.preparedsociety.com/forum/f16/d-i-y-solar-generator-less-than-500-a-15496/


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## LincTex

labotomi said:


> Just an aside:
> The amp-hour capacity is set at a specific rate. That capacity will be different at rates other than the one listed.


Correct... in other words, a large rate of discharge will give you less than rated. A small rate of discharge will give a little more.

Remember, a lead acid battery is just a big chemical reaction.

*LOTS* of things affect how much energy goes in, and how much energy comes back out!!! (the two are never equal, BTW)


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## Cast-Iron

For most systems where the panels are rated at greater than 5 watts and you have 125 amp hour (or greater) battery capacity (_rule of thumb: 1 watt per each 25 amp-hours of capacity_), you will need a charge controller rated higher than your system's peak charge rate to protect your storage batteries from overcharge damage. Additionally, a power inverter (sized to your peak demand load) with a low voltage interrupter will keep you from damaging your batteries by drawing them down too far. 200 watts is a fairly small system for all the electronics you described. Refrigerators, even small ones, can easily draw several amps at 120 volts. With a 90% conversion efficiency and a 5 amp draw, you would need about 700 watts for every hour of run time (_watts = amps x volts_). So if it cycled for 15 minutes every hour, it would use nearly all of your power generated leaving nothing left to power anything after the batteries are depleted and you lack enough light for power generation. You may only avg 4-6 hours of charge time per day, it varies a lot with the season and your latitude.

Your better off calculating what items you really have to power (inventory), how much each will be used (energy budget), what your maximum use at any one time would be (max load) and have enough battery reserves to endure a couple of overcast days (storage capacity).

The costs can add up quick so play around with different lists and you'll soon figure out what "necessities" you can or can't afford to do without.

Good Luck!


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## Jackal01

Cast-Iron said:


> For any system where the charge rate is more than around 10 or 20 watts, you should have a charge controller correctly sized for your system's peak charge to protect the batteries. Additionally, a power inverter (sized to your peak load) with a low voltage interrupter will keep you from damaging your batteries by drawing them down too far. 200 watts is a fairly small system for all the electronics you described. Refrigerators, even small ones, can easily draw several amps at 120 volts. With a 90% conversion efficiency and a 5 amp draw, you would need about 700 watts for every hour of run time. So if it cycled for 15 minutes every hour, it would use nearly all of your power generated leaving nothing left to power anything after the batteries are depleted and it gets too dark. You may only avg 4-6 hours of charge time per day, it varies a lot with the season and your latitude.
> 
> Your better off calculating what items you really have to power (inventory), how much each will be used (energy budget), what your maximum use at any one time would be (max load) and have enough battery reserves to endure a couple of overcast days (storage requirements).
> 
> The costs can add up quick so play around with different lists and you'll soon figure out what "necessities" you can or can't afford to do without.
> 
> Good Luck!


That makes sense. A fridge is a luxury in a power outage. The wife and I dont keep a lot of food in it so we could consume the food before it spoiled without running it. Not to mention our freeze dried food is always stocked for a couple days. We have extensive backpacking supplies also. This is more of a portable system for getting away/camping. Running lights in the campsite. Charge small devices. we dont use air mattresses or anything like that. I just considered our fridge for the hell of it. I planned on the box/gen weighing in around 140-200 with both batteries and other components. Going to put it all in a box with casters. Probably a rolling tool box type of thing. Money wise...planning on around 900 total. I also plan to build a system of the house/larger appliances later on. We have a gas generator that we could borrow but I have been wanting a "yeti" type generator for far cheaper and far better. Just cannot believe the price of it. The only necessary items would be a couple fans, lights and chargers. Living in Houston during a summer power outage is deadly stuff. Winter I am not worried as we have natural gas for the water and fireplace and well...we can sleep in our 15 degree mummy bags. Again...this is not so much for the house to power house hold items.

I appreciate the input and I hope I am being clear on my end to yall!


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## LincTex

Jackal01 said:


> This is more of a portable system for getting away/camping. Running lights in the campsite. Charge small devices. Again...this is not so much for the house to power house hold items.


Sounds like the system I built for when I built my bug-out location. I only used it to run power tools (the saw and drill are only used a few seconds at a time), radio and fluorescent work light.

It was just two marine deep cycle batteries (larger of the two common sizes) in parallel, A Xantrex C35 charge controller, and 9 harbor freight solar panels (3 kits worth), and a harbor freight inverter (700w/1400w). I didn't use a voltmeter. I never ran out of juice. I also seldom worked for a full, solid day.


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## Jackal01

LincTex said:


> Sounds like the system I built for when I built my bug-out location. I only used it to run power tools (the saw and drill are only used a few seconds at a time), radio and fluorescent work light.
> 
> It was just two marine deep cycle batteries (larger of the two common sizes) in parallel, A Xantrex C35 charge controller, and 9 harbor freight solar panels (3 kits worth), and a harbor freight inverter (700w/1400w). I didn't use a voltmeter. I never ran out of juice. I also seldom worked for a full, solid day.


Yea. Our setups do sound similar. Now I just need to get all the stuff! :droolie:


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## hiwall

You have looked at how large those 100 watt panels are, right? 
Here is one just to show size 47"x22". Is that very portable?
http://www.ebay.com/itm/100W-Watts-...727?pt=LH_DefaultDomain_0&hash=item4173eec39f
I use a 200 watt system on my motor home and it seems to work fine. I run a small refrigerator, lights, and any electronics I happen to have with, plus the intermittent use of the water pump. I have four batteries but they are far from new


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## Jackal01

hiwall said:


> You have looked at how large those 100 watt panels are, right?
> Here is one just to show size 47"x22". Is that very portable?
> http://www.ebay.com/itm/100W-Watts-100-Watt-Solar-Panel-Off-Grid-12-Volt-12V-RV-Boat-USA-Solar-Cells-/281117901727?pt=LH_DefaultDomain_0&hash=item4173eec39f
> I use a 200 watt system on my motor home and it seems to work fine. I run a small refrigerator, lights, and any electronics I happen to have with, plus the intermittent use of the water pump. I have four batteries but they are far from new


Yea I have. They are on the larger end but I like the quality of construction, specs and price. Those look like the same ones. I still need to draw up a mounting method. Havent decided that aspect as of yet.


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## Viking

Caribou said:


> This is going to be a mobile rig so you might want to factor in other considerations. Will you want to park in the shade to keep your rig cool? This will reduce the production of electricity. A less than optimal angle on the sun will likewise reduce production.
> 
> I lived on a battery system for two years. My answer was as large a battery bank as space and weight would allow. I also separated my batteries into an engine battery and a house battery bank. It would have been a real bummer to not be able to start the engine to charge the house batteries or to travel.
> 
> You can get controllers that have multiple inputs so using solar and your alternator are not a problem.


Caribou is right on this, I would add that with the experience I've had, I would not use a marine deep cycle like we used to have on our travel trailer but rather true deep cycle batteries such as golf cart 6 volt batteries with 200 or greater amp hour ratings or batteries designed for solar systems. Our motor home has a separate engine battery and I installed four 6 volt 205 amp hour golf cart batteries for 12 volts at 410 amp hours total with four 100 watt 44 cell solar panels controlled by a MPPT solar charge controller. Even on cloudy days this system gets a good charge, even the engine battery.


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## Jackal01

I was actually looking at the Trojan T105. Two of them. I just hope someone locally in Houston has a couple.


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## Viking

Just to understand why I continue to hammer on about higher cell count panels the following shows what I mean. The panels I'm talking about in my example are all 100 watt for a 12 volt system. The 32 cell panel produces 17.7 full load charge volts and is 21" X 40.8, the 36 cell panel produces 18.5 charge volts and is 21" X 47" and the 44 cell panels I got from the same place but are no longer available, they do a lot of motor home installations and they say that due to the financial downturn people are buying smaller motor homes and so they had to sell smaller panels to fit those motor homes. Anyway my 44 cell panels produce around 21 charge volts but they are larger, I don't have the exact size but I seem to remember they are 22" X 57". I have a MPPT, Maximum Power Point Tracking, solar controller that uses the higher than needed voltage that the 44 cell panels produce to boost the charge current. I don't have the specs handy for the controller in the motor home but I'd guess that it could run at up to 36 volts or more solar input. The thing to understand is that it takes a pretty bad sun day for the 44 cell panels not to give enough charging voltage and if I had 32 or 36 cell panels there could be a possibility of no charging voltage. For our home back up system we got 72 cell panels that produce 36.2 charge volts and our battery bank is 24 volts and so even on not so good of a sun day those panels are likely to produce some charging. The solar controller we have for those panels is a MorningStar TriStar MPPT which can take up to 150 volts from the solar panels and the charging output voltage can be set to 12, 24, 36 or 48 volts. When I talk about a not so good sun day I mean partly cloudy or hazy and we have had this happen out on the desert boondocking and have gotten full recovery charges on all but one totally cloudy day out of six weeks. When I built my motor home shelter I installed a 15 watt panel on top to have a trickle charge system to keep the engine battery and house batteries in good condition but in afterthought I should have gotten a larger panel with more cells as it doesn't do well during winter months and I sometimes have to hook up to 120 VAC and turn on the inverter charge system to maintain the batteries, on good full sun days that panel will produce just over 14 charge volts. My feeling is that I'd rather have more than I need for charging capabilities that end up short when I need the power stored the most.


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## Jackal01

With doing more research on batteries I am unable to really find an answer on here nor the interwebz. Obviously flooded batteries exhaust fumes while charging. This would not work while charging the batteries via the vehicle DC plug while driving. And there really is no safe way to exhaust those fumes without all the window down. I may forgo charging while driving as long as the maintenance isn;t too bad. I have never done maintenance on a flooded battery before. What are the requirements for a couple Trojan T105s. The other option is to use a Trojan 31 Gel 12V at 102Ah. Not as nice as the T105 with 6v at 224 Ah but if Gel is that much safer, I may just go with it but the amp hours is significantly less. Are there any concerns with the flood batteries while not charging but in use ie: sleeping in the vehicle with the battery box (with the inverter, etc)? I see a ton of posts and threads about using these deep cycle flooded batteries but I haven't seen the issue of the venting/exhausting addressed. I am curious what everyone thinks about it. I mean, my Jeep has its battery mounted under the floor under the front passenger but it is an AGM battery. Hence flood acid batteries being in the engine compartment on most other vehicles. I would like to go to T105 route (2 of them) if it will be safe enough and the maintenance won't be a huge speed bump. 

I am now more on the hunt for gel or AGM for the reasons of not wanting to worry about the condition of the battery during times of use, stress, worrying about other things, etc. But they are more expensive and the specs aren't as good in relation to the cost.


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## Caribou

I lived for two years with the batteries of my boat on the other side of the bulkhead from my bunk. There was a sizable opening in the bulkhead just above the batteries. I never had any odor or other problems. My batteries were being charged and/or discharged all night.


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## LincTex

Sam's club has the big golf car batteries for $85, and if you sign up for a credit card you get another $20 off until Dec 31st.

There are "free 1 year membership" cards available on the web somewhere...


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## Jackal01

Caribou said:


> I lived for two years with the batteries of my boat on the other side of the bulkhead from my bunk. There was a sizable opening in the bulkhead just above the batteries. I never had any odor or other problems. My batteries were being charged and/or discharged all night.


Interesting indeed. I guess there really isn't much to worry about but it is more of a CYA? Any input on taking care of them or did you just leave them be for those couple years? I assume you pretty much left them alone.



LincTex said:


> Sam's club has the big golf car batteries for $85, and if you sign up for a credit card you get another $20 off until Dec 31st.
> 
> There are "free 1 year membership" cards available on the web somewhere...


I will check the one down the street. I don't want them to be too large since this will be a portable generator.


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## Viking

When I set up my solar backup system I'll have 20 batteries in an insulated enclosed area below the solar panels to keep them from getting too cold when there is subfreezing weather but they will be vented and what I plan on doing is using one or two computer cooling fans to force air into the battery compartment to clear out the hydrogen gases. Probably the only time the fan(s) will need to run is during charge and discharge periods when there is heat generated from the inverter/charger or solar charge controller. If I pull the air from their compartment with the fan(s) it should help keep the battery bank from getting too cold. I know that when I was in ground support for the Air Force the generators we took to the aircraft had starting battery in them that had heaters under them, it seemed strange to me that it would use the battery to run those heaters but the warmer battery had greater starting power when it was warmed a bit.


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## talob

LincTex said:


> Sam's club has the big golf car batteries for $85, and if you sign up for a credit card you get another $20 off until Dec 31st.
> 
> There are "free 1 year membership" cards available on the web somewhere...


I've been looking at batterys at Sam's looks like now's the time to get serious I'll be needing eight of them, gonna put em in the basement in a battery box venelated thruogh the outside wall.


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## Jackal01

Intersting. I am curious regarding the venting for my system which will be portable and will be possibly charging while driving. 

I am also still curious with the maintenance from someone with experience. I have read some online but I would like the perspective of someone that has done this or similar before.


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## Viking

Jackal01 said:


> Intersting. I am curious regarding the venting for my system which will be portable and will be possibly charging while driving.
> 
> I am also still curious with the maintenance from someone with experience. I have read some online but I would like the perspective of someone that has done this or similar before.


Do you have a trailer to haul your camping gear or do you just carry everything inside your vehicle? If you don't use a trailer you could build a bumper carrier to strap the batteries to with charge connections there. As to maintenance buy a good quality battery hydrometer and always carry a jug of pure distilled water with you. The hydrometer is the best way of telling the condition of charge for your batteries. Never top batteries with anything other than distilled water as tap water may contain minerals that could weaken or contaminate the electrolyte.


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## Viking

LincTex said:


> Sam's club has the big golf car batteries for $85, and if you sign up for a credit card you get another $20 off until Dec 31st.
> 
> There are "free 1 year membership" cards available on the web somewhere...


We don't have a Sam's club anywhere near where we live but that's a pretty good deal. For the 20 six volt golf cart batteries we bought we got from Costco for just over $86 each, however since I had no cores I had to pay an additional $9 each. The Costco batteries are made by Johnson Control and are 205 amp hours. Thing is in the past couple of years the cost of high amp hour rated batteries has increased sharply. The 225 amp hour Interstate batteries are now 230 amp hour and have gone up in the neighborhood of $30 plus each. The Costco batteries had only increased $10 each during the same time period. I have to say that I would have loved to have gotten Rolls Surrette batteries but I'd have to have taken a loan out to get them. AGM batteries are great (and a bit expensive) but they won't off gas while charging/discharging. If used charging voltage needs to be more accurately controlled so as not to "blow out" the sealing. AGM, if you didn't know, means Absorbed Glass Mat. The fiberglass mat is in a sealed chamber above the electrolyte, during charging vapors are absorbed in that mat, condense and drop back into the electrolyte. So the thing is you need to have a charge system that can have set voltage perimeters. AGM's can take occasional equalization charging for clearing plate build up but need to have the voltages less than the regular flooded deep cycle batteries or they could off gas enough pressure to cause the sealing to fail, these batteries are not designed to add water. Just something to think about if you don't want any acid/hydrogen vapors in an enclosed area, then the AGM battery may be what you want.


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## Jackal01

Viking said:


> Do you have a trailer to haul your camping gear or do you just carry everything inside your vehicle? If you don't use a trailer you could build a bumper carrier to strap the batteries to with charge connections there. As to maintenance buy a good quality battery hydrometer and always carry a jug of pure distilled water with you. The hydrometer is the best way of telling the condition of charge for your batteries. Never top batteries with anything other than distilled water as tap water may contain minerals that could weaken or contaminate the electrolyte.


Negative. No trailer. I have a rear tire carrier that is attached to the hitch receiver so adding more weight back there may not be ideal. I called a local Trojan dealer yesterday and he gave me a great deal via phone. T105 6v 225 ah (I think) deep cycle for $124 with no trade in. At first he said $150 and put me hold then told mw that so it seems like a good deal to me. They have a 12v 105Ah Gel for $334. Little high but no maintenance.


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## Viking

AM Solar is the business we bought our four solar panels from for our motor home and they used to say on the solar education page of their website that they didn't recommend Gel cell batteries and lately they highly recommend the AMG batteries. I have heard a few people mention that there has been some problems with the latest manufactured gel batteries and that it may have to do with a change of ownership and the way they are built. As to the Trojan batteries I've heard they are very good, just a bit too expensive for me however $124 isn't that much different than the price for the Interstate 230 ah six volt golf cart battery that was quoted to me a few years back.


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## Jackal01

Viking said:


> AM Solar is the business we bought our four solar panels from for our motor home and they used to say on the solar education page of their website that they didn't recommend Gel cell batteries and lately they highly recommend the AMG batteries. I have heard a few people mention that there has been some problems with the latest manufactured gel batteries and that it may have to do with a change of ownership and the way they are built. As to the Trojan batteries I've heard they are very good, just a bit too expensive for me however $124 isn't that much different than the price for the Interstate 230 ah six volt golf cart battery that was quoted to me a few years back.


Good to know.


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## LincTex

I would buy FLA (flooded lead acid) because of their ability to maintain.

I like AGM for what they are, but they *are* expensive.

I will never waste my money on gelled acid batteries.


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## talob

LincTex said:


> I would buy FLA (flooded lead acid) because of their ability to maintain.
> 
> I like AGM for what they are, but they *are* expensive.
> 
> I will never waste my money on gelled acid batteries.


I've gotta agree with LincTex, I've been trying to educate myself on batterys because I need to get eight of them for the system I'm setting up here, from what I read I havent even considerd the gel cells, the batterys I'm talking about here are all six volt without core charge, Sams has a GC2 AGM 190AH for 180$ a EGC2 230AH flooded cell for 110$ these are Duracell from what I understand Dekka makes em, I checked with a local golf cart shop he has the trojans I believe 225AH's for just a little more than the EG2 flooded but core charge was a lot higher. So it looks like it's the flooded cell for me down side to em compared to AGM is off gassing (ventilate) maintence (tlc) up side is a little more AH for a whole lot less money and from what I understand the lifespan (charge cycles) of the flooded cell is at least as good or even a little better than the AGM, if I'm missing something someone please educate me.


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## Jackal01

I think the maintenance is worth the money saved and better specs. Until AGMs go down I think FLA is the way to go overall.


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## Viking

Actually FLA battery maintenance isn't all that bad, just design the battery box or tray so that you have easy access to the caps. Our original set of motor home house batteries consisted of two old and to new 6 volt golf cart batteries with a series/parallel connection I install the two new ones in back and the old one up front for easier access for topping off the cells. When the old set was beginning to get tired I bought some Battery Equalizer fluid from batterystuff.com to add 1 oz. per cell to help reduce sulfation, it seemed to work as I got two extra years of use out of them before getting a new set. I replace all four so I'd have a matched set even though the two Interstate batteries were still in good condition. One thing I found was that the cell caps on the original batteries didn't seal all that good and tended to leak electrolyte on the tops of the batteries so I got another set of caps from Interstate that had three caps connected together with closing levers, they sealed much better. It probably wouldn't hurt to use electrical grease for connections to help keep corrosion to a minimum.


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## Jackal01

Again, unable to find my answer on the interwebs and here. It is a long question so perhaps that is why.

With a solar generator (homemade) is it possible to charge it via AC outlet? IE keep it plugged in the wall 24/7. Does the inverter have anything to do with that?


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## cowboyhermit

Jackal01 said:


> Again, unable to find my answer on the interwebs and here. It is a long question so perhaps that is why.
> 
> With a solar generator (homemade) is it possible to charge it via AC outlet? IE keep it plugged in the wall 24/7. Does the inverter have anything to do with that?


An "intelligent" charger can be used to keep the batteries charged on AC, if you are using 12V then it's no problem, higher voltage you will have to shop around.

You can also get inverters that have a charging function that will switch over when AC is disconnected (like a UPS).


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## Jackal01

http://www.altestore.com/store/Char...0A-Charge-Controller-with-Display-1224V/p790/

That is the one I plan to get.


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## Viking

Jackal01 said:


> Again, unable to find my answer on the interwebs and here. It is a long question so perhaps that is why.
> 
> With a solar generator (homemade) is it possible to charge it via AC outlet? IE keep it plugged in the wall 24/7. Does the inverter have anything to do with that?


Both of the inverters we have are the inverter/charger types. If you go to www.donrowe.com they have all kinds of inverters and combined inverter/chargers. This is where we bought our inverter/charger units, mainly for two reasons, the first being that it was only around 100 + miles away which picking it up ourselves more than saved money if they had shipped it to us, and secondly, we saved over $500 dollars for the one we got for our motor home by getting it from them over buying it at an RV supply store just 25 miles away.


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## cowboyhermit

Jackal01 said:


> http://www.altestore.com/store/Char...0A-Charge-Controller-with-Display-1224V/p790/
> 
> That is the one I plan to get.


That charge controller is a good one, not MPPT but have seen lots of those in use and they seem to function very well.

If you are going to get a 110V charger you should get one with a similar output program; full charge, float etc. usually called intelligent charging. Something like this for instance http://www.jameco.com/1/1/5061-pb-1000-12-1000-watt-intelligent-single-output-lead-acid-battery-charger.html Of course they can be found much smaller and cheaper. The old "automatic" chargers are not made to be left on indefinitely and may harm the batts over time.

The inverter/chargers make things simpler and work fine as well.


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## Viking

cowboyhermit said:


> That charge controller is a good one, not MPPT but have seen lots of those in use and they seem to function very well.
> 
> If you are going to get a 110V charger you should get one with a similar output program; full charge, float etc. usually called intelligent charging. Something like this for instance http://www.jameco.com/1/1/5061-pb-1000-12-1000-watt-intelligent-single-output-lead-acid-battery-charger.html Of course they can be found much smaller and cheaper. The old "automatic" chargers are not made to be left on indefinitely and may harm the batts over time.
> 
> The inverter/chargers make things simpler and work fine as well.


Both the Xantrex and Magnum Energy inverter/chargers we have are of the "intellegent' types they start charge at Bulk then to Absorb then to Float and Full Charge depending on what the level of charge the batteries are in. Both inverter/chargers have an Equalization charge stage that is set manually to stir up stratified electrolyte which helps reverse battery plate sulfation that occurs over time due to discharge and charge cycles. This stage is timed and what it does is give the batteries a much higher charge voltage than is used the regular charge cycle.


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## Jackal01

cowboyhermit said:


> That charge controller is a good one, not MPPT but have seen lots of those in use and they seem to function very well.
> 
> If you are going to get a 110V charger you should get one with a similar output program; full charge, float etc. usually called intelligent charging. Something like this for instance http://www.jameco.com/1/1/5061-pb-1000-12-1000-watt-intelligent-single-output-lead-acid-battery-charger.html Of course they can be found much smaller and cheaper. The old "automatic" chargers are not made to be left on indefinitely and may harm the batts over time.
> 
> The inverter/chargers make things simpler and work fine as well.


So with the one that I chose I have the ability to charge the batteries via AC/house hold power?

I do not think I need to drop the big bucks on MPPT quite yet since this will be a portable solar generator. Perhaps if I ever dedicate to be for the house I will but I think the one PMW one will work fine unless you fine folks think otherwise. I have budget to keep in mind too. I think the components I have chosen are of good quality. I know the inverter isn't pure since wave but again, money. I dont plan on using this on any sensitive equipment, either. Just some lights, fan, cell phones, flashlight charger, a radio.

Renology Solar kit
Morningstar Charger Controller
Whistler Inverter


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## cowboyhermit

Jackal01 said:


> So with the one that I chose I have the ability to charge the batteries via AC/house hold power?


Ok, not 100% sure about what you are doing but first of all that kit comes with a charge controller so I assume you are buying the Morningstar for some reason. At $1.65ish/watt the panels are not a bad deal, if you factor in the charge controller the deal is better. Neither of those charge controllers (or any that I have seen) can be used to charge the batteries with AC power. The only component that typically can double as a way to charge batteries from AC is the inverter and that one doesn't have that function. I would not be too concerned about using a non-sine wave inverter in fact I still use them all the time for various applications.


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## Jackal01

cowboyhermit said:


> Ok, not 100% sure about what you are doing but first of all that kit comes with a charge controller so I assume you are buying the Morningstar for some reason. At $1.65ish/watt the panels are not a bad deal, if you factor in the charge controller the deal is better. Neither of those charge controllers (or any that I have seen) can be used to charge the batteries with AC power. The only component that typically can double as a way to charge batteries from AC is the inverter and that one doesn't have that function. I would not be too concerned about using a non-sine wave inverter in fact I still use them all the time for various applications.


Gotcha. I have that controller picked out presently because it has more functions to it than the one in the kit. My plan is a portable solar generator. A couple panels. A couple 6V golf cart batteries for a 12v application. So I need to look at an inverter than can do the AC charging that I desire.


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## LincTex

Jackal01 said:


> So I need to look at an inverter than can do the AC charging that I desire.


I don't see why.

Any normal 12 volt automotive battery charger can charge your battery pack from an AC outlet.


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## Jackal01

LincTex said:


> I don't see why.
> 
> Any normal 12 volt automotive battery charger can charge your battery pack from an AC outlet.


....I never even thought of that.:sssh:

So would it matter where the alligator clips go on the two batteries? I would think not but would rather just double check. And of course I would invest in a good charger that has the different stages so I can keep it plugged in, correct? Which are pretty cheap anyway.


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## smaj100

I personally connect my battery charger at opposite ends of the bank to ensure that the juice is flowing through them all and not stopping at one for a longer amount of time than needed.


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## Jackal01

smaj100 said:


> I personally connect my battery charger at opposite ends of the bank to ensure that the juice is flowing through them all and not stopping at one for a longer amount of time than needed.


Make enough sense. I guess a Battery Tender would work. I have heard they are great for maintaining batteries. Just keep it plugged in until I need the generator. And it is small enough to keep/mount it inside the box everything else will be in.


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## LincTex

If you use two 6 volt batteries in series, that makes 12 volts. Use a 12 volt charger attached "at each end" like smaj100 said so that the charger sees 12 volts.

If you have two 12 volt batteries in parallel, you connect the clips to either battery; both will get the same charge.


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## DM1791

I just want to make sure my math is working right....

Battery bank set up:

2 batteries per array in series: each battery has 12v 200AH rating
3 arrays paralleled for the bank

Totals: 24V and 600AH (at the 20hr rating of 10A per hour)

This math sound right?


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## LincTex

DM1791 said:


> 2 batteries per array in series: each battery has 12v 200AH rating
> 3 arrays paralleled for the bank
> Totals: 24V and 600AH (at the 20hr rating of 10A per hour)
> This math sound right?


Yes, that sounds correct


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## smaj100

Can you use a 120vAC wall switch for normal 12v dc power? I want to wire some led lights up in our barn and storage building off the solar system.


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## cowboyhermit

smaj100 said:


> Can you use a 120vAC wall switch for normal 12v dc power? I want to wire some led lights up in our barn and storage building off the solar system.


Not _supposed _to use a switch with DC that isn't labeled for it AFAIK. Some are labeled/listed for both. DC arcs differently than AC. In reality, yes you can, especially with low voltage, I have done it a lot.

Lots of DC switches/toggles to choose from but I guess you are using existing wiring?


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## smaj100

Cowboy, I am running new wiring for the shed and barn, but have an excess of light switches and wall outlets (probably wont use those), I figured they might be different but that it couldn't really hurt, for a 12v low amp system for lights.


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## LincTex

smaj100 said:


> I figured they might be different but that it couldn't really hurt, for a 12v low amp system for lights.


Low amperage is the key. A typical "Leviton" light switch will turn on and off 15 amp AC loads easily, sometimes for decades before needing replacement. I'd certainly not go over 10 amps DC, maybe limit to 5 to be sure.

The OLD light switches that went "Snap-Snap" can easily handle more amps than these new-fangled "silent" ones.

LED's are awesome, but some driver designs have a nasty habit of drawing more current as voltage falls down. The arcing problem gets worse with a battery that's low versus a fully charged system.

I use two sets of lights in my DC systems. "Dark breakers" are low-draw, low-output lights that put out just enough "area light" to help me get to where I am going without running into stuff. Then the "high-output" lights are only used locally, in the location I am working or reading.


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## LincTex

I was just browsing ebay for switches... some neat options.

I would avoid the lighted ones.

If you need a light to find the switch in the dark, you can get REALLY "low-draw" LED's (you'll have to solder a resistor on to it) for cheap (or even free if you like to chop up old broken children's toys) to mount near the switch.


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## cowboyhermit

Yeah the old levitons like we had here were very "snappy"  they are rated for AC/DC, unlike most of the newer styles. Still available here but not cheap. Make sure you check that the ones you have aren't rated DC anyways, it should be clearly marked.


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## LincTex

cowboyhermit said:


> Yeah the old levitons like we had here were very "snappy"  they are rated for AC/DC, unlike most of the newer styles. Still available here but not cheap. {IMAGE}


Love those things. All of our outbuildings in North Dakota had them. They are made to last 100 years.


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## cowboyhermit

LincTex said:


> Love those things. All of our outbuildings in North Dakota had them. They are made to last 100 years.


Our barn and outbuildings too 

They worked good for retrofitting power into old buildings because they don't need a box and are fairly enclosed. Especially with surface mount wiring, the cost isn't bad.

For most things DC I use rv, electronics (computer), or auto part type switches. The only issue is they aren't very "standard" in terms of mounting. Many of the toggles use the same diameter shaft though, so it isn't too bad really.


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## LincTex

cowboyhermit said:


> The only issue is they aren't very "standard" in terms of mounting. Many of the toggles use the same diameter shaft though, so it isn't too bad really.


Yeah, that is the standard - 1/2" hole "panel mount" toggle switches. I wish more surface mount options were available.


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## Tirediron

A little cheat for A/C switches used on D/C applications. 
once a year switch the wires to the opposite pole, so that the arc transfer reverses itself.

not a perfect solution.

there are also D/C rocker switches designed for 20 amp @ 12v loads


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## LincTex

Tirediron said:


> once a year switch the wires to the opposite pole, so that the arc transfer reverses itself.
> 
> ...not a perfect solution.


Well, it doesn't "reverse" the damage, it just arcs the other side. But I think that is what you meant!



Tirediron said:


> there are also D/C rocker switches designed for 20 amp @ 12v loads


A GREAT source of these is from old "junked" school buses and semi-trucks!


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## Caribou

You can get higher amp rated switches but your question is about the ones that you already have.

The issue is the number of amps. Make sure that your wire is large enough and is a multi stranded wire as the multi stranded wire carries more current. DC takes a larger wire than AC. The longer the DC run the more the line loss. You can get a significant voltage drop which will cause the amperage to increase, this is where the switch capacity could be a problem without proper wire sizing.

When sizing AC wire you measure the length of the run. In sizing DC wire you include both the length of the run and the return.

Do not use the same outlets for AC and DC. The outlets will work just fine but if you plug in a 12V item into a 120V outlet by mistake the results will not be to your liking. The 120V items will not appreciate the 12V either. Even if you do not screw up someone less aware of your system may well make a mistake. The risks are too high. The option is to pickup other outlets and plugs, from another country for example. Europe has a number of outlet designs.


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## cowboyhermit

LincTex said:


> Yeah, that is the standard - 1/2" hole "panel mount" toggle switches. I wish more surface mount options were available.


For anywhere that has something approaching an "instrument panel" I like the standard toggles, I usually just grab a piece of aluminum angle bracket and drill some holes. Pretty much everyone thinks it looks neat or "retro"

But, yeah, have always found just mounting a single switch to be more difficult than it should be. Whether it's parts availability or aesthetics (whatever that means) You can find some surface mount switches that can just be screwed on but they have been less common than I would expect.

I have used common electrical boxes, and put a toggle in them, it works out pretty easy most of the time. Used a coax terminal metal plate and have drilled a hole in a solid cover panel. Finding a faceplate is sometimes tricky for just a one-off project.


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## smaj100

For the price, I can pick up multi packs of 12v 15A rocker switches and just make a bracket to mount them to the walls for lights. I was just hoping to use the ones on hand as we just bought a new house and I have a bunch leftover from previous houses and rentals. To me it's not worth the risk of a possible fire from arcing considering livestock will be in the barn and the chickens live in 1/2 of one of my sheds. These are low watt 10 led floods that I am installing so I am looking at 1.2A ea and will be installing 2-3 at most on each circuit. I so have multi stranded wire to use but if I need a larger gauge I have plenty of 10-3 romex.


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## LincTex

smaj100 said:


> These are low watt 10 led floods that I am installing so I am looking at 1.2A ea and will be installing 2-3 at most on each circuit.


You have nothing to worry about.

As a side note, I have found LED bulbs are not as near fussy about line voltage drop as my other DC powered items are.


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## smaj100

Finally added my wind turbine to my solar system. It's spinning and making slow steady power. It's not installed in an ideal location as it gets a bit of swirl from the surrounding trees. I'll take slow and steady for recharging the batteries.

It's a 400w hye that i picked up from amazon.


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