Battery Care

[BobT]

I did a bunch of research to reply to another thread and thought my findings might be useful so I started this thread. Hope it helps clear up some mud.

It seems we all have questions about how to properly recharge our deep-cycle batteries. I have posed questions to Schumacher and battery OEMs and here is a general compilation of my results.

For Deep-Cycle and Dual-Purpose batteries:

* Avoid cycling (discharging) deeper than 50%.

* Recharge your battery as soon as possible after each use.

* Recharge your battery quickly using a higher amp setting on your charger such as 15A except when cycled deeper than 50%.

* If you cycle your battery deeper than 50% use a trickle charger to bring it up to at least 50% and then switch to the higher amp setting. Batteries at <50% charge state will draw high current from the charger and this could damage the battery.

* The best charger to use is a fully automatic charger that incorporates three-stage or four-stage technology. The four stages are Trickle, Bulk, Absorption, and Maintenance.

* It will not harm a deep-cycle battery to use the regular battery setting on your charger but your deep-cycle battery may not reach full charge.

* Use the deep-cycle battery setting of your charger for dual-purpose batteries.

* It will not hurt your battery to place it on a concrete floor. New batteries use a different case material that insulates it better.

* Heat is a battery’s enemy.

* Cold reduces a battery’s current capacity.

* Do not add electrolyte to a battery.

* Do not use tap water to top off your battery. Distilled water is best.

* Electrolyte level should be kept above the lead plates but do not over-fill. Leave at least one-half inch of air space.

Hope this is helpful.

[harvey lee]

Very good post Bob. I did always think that concrete was bad for batteries and set them on a 2x4 in the garage.

[BobT]

Another thing that occurred to me in my searching was that I didn’t notice anything about charge memory so I did a little more digging. Most of us that have been around a while grew up with the notion that it was necessary to periodically deeply discharge a deep-cycle battery to avoid charge memory problems. The idea was that if you repeatedly cycled a battery only to about 50% and recharged it, it would develop a memory and lose capacity.

The common term for this phenomenon is “memory effect” and is a myth with lead-acid batteries. In fact, as I posted earlier, it is preferred to avoid cycling a battery deeper than 50% and if you do you should practice special recharging procedures to prevent damaging the battery. Memory effect is a common problem with Nickel-Cadmium (Ni-Cad) but lead-acid and gel-cell batteries are not affected.

[TooTallTom]

BobT, thanks for the post. I learned a bit, and did have some of that mud cleared up for me. I appreciate the effort to help us all out.

Tom.