Ask John

Q:How Can I Restore An Old Battery To Like-New Condition?

posted August 26th 2010 at 9:45AM

The bad news is that a single set of deep cycle battery cells can cost you a thousand dollars or more. That’s an optimistic fact. But it’s also true what I’ve been telling people for years here… You can get the same batteries, and enjoy practically the same performance for no (or at least very little) money. Well, it’s tough to keep a good secret when you exist on the web! The truth is that deep cycle batteries are used in all kinds of equipment that are probably in regular use no matter where you live. This means that you can get your hands on them for free. But how? Start by scouting around for places where you might find forklifts, golf carts or other unfueled utility vehicles that plug-in to charge. Marinas are also good sites to check given how common deep cycle batteries are in yachts, houseboats, and pleasurecraft.

Talk to whoever’s in charge and ask about their deep cycle battery turnover rate. See, eventually, after repeated charging and draining of these industrial batteries, sulfates begin to build up on the inside of the batteries’ cells. Theses sulfates solidify and eventually prevent the batteries’ acids from reacting to create energy. This makes the batteries appear to be dead, but this couldn’t be further from the truth: All that is required to bring these batteries back is to apply a process called desulfation to the cells using a simple and affordeable device called a “battery conditioner”, “trickle charger” or “battery desulfator that is common and widely available.

Heads-up for this next part… This is not a difficult process, and everyday people do this all the time – some as a side-business – but it is still important that we do things in the right order, and take the appropriate safety precautions. You should be wearing a pair of safety glasses and corrosion-preventative gloves to be safe.

A basic battery desulfator will cost you roughly $45 to $50. However, these are simple devices, and you can even make them yourself with parts costing around $10 total, or so. Hopefully soon, I can get some instructions up here on how to piece one together using only a voltage meter, a heavy bolt, and two different thicknesses of wire. In the meantime, I’ll assume that if you want to go this way, $50 at the store is not an exorbitant expense… Especially since refurbished deep cycle batteries can be sold for $300 to $400, or more! Not a bad return-on-investment, if you ask me.

Proceed by carefully following the steps below:

• The very first thing you must do is asses the state of a deep cycle battery to determine if it can be restored. Use battery terminal cleaner on both terminals to ensure that they are clean. Be sure to identify which terminal is positive(+) and which is negative(-).

• With a volt meter (sometimes called a “load tester”), attach the positive lead to the positive terminal, and the negative lead to the negative terminal.

• If you get a reading lower than 12 volts it will be very difficult to restore the battery and you should look for a better cadidate.

• If you get a reading of at least 12 volts, you’ve got a a battery that you can use. Disconnect the volt meter.

• You want to make sure that your batteries are drained completely before you begin the desulfation process. Hooking it up to an old light for a day or so is ideal for this purpose, but any device will do.

• When you get a reading of zero, attach your batter desulfator’s leads in the same fashion.

Then you simply switch the desulfator on, and let it do its thing. This should take about 24 hours. The reason that these little gadgets are sometimes called “trickle chargers” is that they are designed to take a long time to recharge batteries. This is good since, a slow trickle-charge will reduce the amount of sulfates that will build-up over time. If the initial yield appears to be significantly below spec you may have to repeat the process. But each time you do, you will notice your batteries’ total capacity increasing gradually. Do this regularly, and your batteries that cost you nothing in the first place will continue to work at 80 to 90 percent efficiency for years to come!

Sincerely,

John Russel

Electrician, Researcher, Inventor, Home Energy Consultant, and Creator
of the Power4Home System