Lead acid batteries, Mmmmm i always think of a block of toxic waste when i hear the word lead acid.Batteries are the dirty part of a renewable energy sytem in my opinion but nearly always unavoidable so love em or hate them there here until another method of storage can be used or invented.Lead acid batteries basically come in 2 flavours, theres cranking batteries and deep cycle batteries. Cranking batteries are for starting engines and can deliver hundreds of amps for a short period of time. Deep cycle batteries are designed for deep discharging but will live longer if there not over discharged. Lead acid batteries are recyclable but i often wonder how many make it to the recycling plant, car batteries are often dumped in the street or thrown on waste land. This is were i come into play, people give them to me and so far i have reconized 2 reasons why they give up. The first and most common on cranking batteries is shorted cells, this is when bits break of the plates drop to the bottom of the cell and when the build up gets high enough to touch the base of the plates they short out rendering the cell useless. The second is sulfation were deposits stick to the lead plates and hide the plates from the electrolyte ( acid ). Theres a few sites on the web about how to revive dead batterys and i have found a way to determine if the batterys is sulfated or has shorted cells. You need a battery charger and a hydrometer, remove all the cell caps and put the battery on charge. I have a charger with 2 settings being 3 amps for low and 6 amps for high charge and prefer to put a dead battery on charge for 16 - 20 hrs at 3 amps.Once the battery has been on charge for 16 hrs check to see if all the cells are gassing the ones that are not gassing indicate a bad cell. Also look at the meter on the charger you need one with a needle not with leds for this part, if the needle is bouncing this shows there is a short in one or more cells although its usaully just one cell. Im using a 100 ah battery at the moment and went through this proccess and found that one cell was heavilly sulfated but not shorted. It gassed a little and when i took readings with the hydrometer this cell had the lowest reading. Heres what i tried.........
First i drilled a hole in the bottom of the bad cell to drain it of.
Next i passed running water through the cell to wash it out, i would have used this method if the cell was shorted.
After washing out the cell i rinsed it with distilled water, wiped the cells drain hole i drilled and using a hot glue gun filled the hole with molten plastic. Then refilled with distilled water and placed on charge @ 3 amps overnight.
