# Maintaining Deep Cycle Batteries



## dksac2

If you don't take care of your wet cell deep cycle batteries, they will degrade and be useless when needed. The two things that kill more batteries than anything else is overcharging or leaving them in a discharged state. Overcharging gel cell batteries is really bad for them. The following that I am talking about applies to wet cell batteries.
If you do not have a need for the deep cycle batteries at this time and wish to have some to put away, buy them without the battery acid in them and have the acid to pour into them when they are ready to be used. This way they will be fresh when needed.
To keep your batteries in top shape, they must be kept properly charged. The thing that kills batteries is Sulphation that builds up on the battery plates. These are crystals that build up on the battery plates that stop the chemical action that produces the electricity. This happens to batteries that are properly maintained over time, but builds up far faster when batteries are overcharged or left in a discharged state. There are chargers that remove the Sulphation from the battery plates as they charge. 
You must keep the acid level up to the fill line at all times. Never add more acid if your batteries are low on fluid, only add distilled water. The acid stays in the batteries, the water is what goes away.
As to the battery chargers. I have two different models of the same brand. Both are made by BatteryMINDer. One is a 1.3 amp trickle charger and will charge up to 6 batteries of like style. The other charges at up to 6 amps for faster charging. The lower priced one is $50, the other $100. 
Both of these chargers have a Desulphation feature that rapidly removes Sulphation from the battery plates. When used in regular charging mode, they charge and remove Sulphation at the same time. When the batteries are fully charged, the chargers drop into a maintenance mode that keeps them fully charged without overcharging. You want to keep the chargers hooked up to the batteries at all times. Your batteries will last at a minimum of twice as long and up to six times longer than batteries that are poorly maintained.
There are a couple of other brands of chargers that remove the Sulphation on the market, but I have not used them.
If you have a weak battery, as long as it is not shorted out, the Desulphation process can make them usable again in many cases. It depends on how far gone they are.
The other thing that kills batteries is running them down below 10.5 volts or 50% before recharging them. The more your batteries are run down at each use before recharging, the fewer recharging cycles you will get from them.
In trying to save a weak battery, first charge the battery. If the battery is fully charged and does not have more than 10.5 volts, it is shorted and is junk. If the voltage is at least 11 volts, try Desulphation to see if the battery can be brought back to a usable state. It will never perform as good as new battery, but may be usable. Approx. 75% of batteries are replaced because they will no longer hold a charge is because of Sulphation. The sooner a bad battery is Desulphated, the better chance you have of saving it. Be sure to wear protective glasses and clothing when working on batteries as the acid can blind you and cause burns on your skin. The gasses given off from batteries are also explosive. Do not smoke, have an open flame or sparks anywhere near your battery when the caps are off. Work on them outside if possible.
Use and charge your batteries correctly and they will last a long time.

JK


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## NaeKid

Good information there ... 

I have a question. I have a small solar-panel that I have attached to the deep-cycle (liquid) RV batteries for my camping trailer. The small panel states that it will keep a battery good during long periods of non-use (ie: winter).

I have seperated my battery from the trailer and put it in a temperature controlled zone, the solar-panel is sitting in a window to gather afternoon-sun and the wires are hooked properly to the RV batteries pos/neg posts properly. Would you agree that this is a good way to keep batteries good for the winter-time, or, would you have a better plan for me to go with?

I also use the same solar-panels in my vehicles that are rarely driven during the winter to keep the battery topped up. I leave the battery attached in the vehicle, the vehicle's clock and such will continue to run through-out the winter and the battery seems to do well enough.

Any other ideas for me?


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## sailaway

Have you checked your 12v system lately, humidity on the sailboat causes things to deteriorate a little faster. I noticed some white powder flake build up on one terminal and a little rust on the starter end. Also one of my Jeeps wouldn't start the other day, I hadn't driven it in a long time and had to clean the connections from the battery to the starter to get it to start. I hit everything with corrosion block and all is working well right now.


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## NaeKid

I just did some testing last weekend on a 40-watt solar-system and that 12-volt RV battery. I was trying to run a small 12-volt cooler off of the battery / solar system. It seems that 40-watts of solar generating power (at about 22.5 volt at high-noon) isn't enough power to keep the battery topped up and running the cooler at the same time.

I am not positive (I don't have a meter to verify), but, I believe that the 40-watts of solar was only putting out around 3.5-amp to 4-amp of power. My 80-watt panel tops out around 8-watt if I remember the paperwork properly.

More testing / design needs to be done now ..


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## Tex

I think you are getting Amps and Watts mixed up. Watts = volts x amps or Amps = Watts/Volts. It sounds like your panels are doing well if I understand you correctly.

A 40W panel will put out 3.5-4A @ 13-14V. An 80W panel will put out 6-8A @ the same voltage.

Since you only get a few good hours/day, you won't keep up with most continuous 24 hr loads.

I have a couple of deep cycle batteries that I keep charged for camping or whatever. (I have an endless supply of used deep cycle batteries from work) I ran a DC outlet to the back of my Jeep and charge them every once in a while. Just don't forget to disconnect the batteries when the Jeep is off or you may drain your Jeeps starter battery.

PV panels are more efficient when they are kept cool. If it's cooler inside, hang the panel on the inside of your window. If it's cooler outside hang the panel on the outside.


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## sailaway

Thanks for the info Tex, a good book to get is: "Living on 12 Volt with Ample Power". I loaned mine to an electrician friend and will post the author when I get it back.


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## NaeKid

I am going to have to find a copy of that book - could it be found on Amazon?


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## pills

Amazon.com: Living on Twelve Volts With Ample Power (9780945415053): David Smead, Ruth Ishihara, Nancy Overman: Books


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## sailaway

What is sulphation and how do you desulphate?


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## UncleJoe

I wondered about this when I first read this thread so I googled it and marked this page.
Battery Desulfation - Storage
It's something I've wanted to try on a couple of old batteries but haven't got around to it yet.


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## northernontario

UncleJoe said:


> I wondered about this when I first read this thread so I googled it and marked this page.
> Battery Desulfation - Storage
> It's something I've wanted to try on a couple of old batteries but haven't got around to it yet.


I actually bought the supplies to make several of those... I just haven't finished assembling any of them. Started one weekend when the wife and son were away, but got busy with other things. Maybe this winter.

I've been following the blog from this guy... Mikey Sklar... who saw that original desulphator design, and decided to improve it. 
his blog... Holy Scrap Hot Springs
his desulphator... :: Mikey Sklar :: Electric Clothing :: Holy Scrap Hot Springs: Bulk Desulfators

He is also working on another desulphator... Holy Scrap Hot Springs: Battery deluxe (BatDLX)


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## UncleJoe

Let us know how it works when you finish.


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## sailaway

UncleJoe said:


> I wondered about this when I first read this thread so I googled it and marked this page.
> Battery Desulfation - Storage
> It's something I've wanted to try on a couple of old batteries but haven't got around to it yet.


Thanks Uncle Joe that page was quite interesting.


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