Most battery banks need maintenance only 4 times a year or so. But after you first install your system, check the batteries every month for a while just to make sure. If the electrolyte level gets below the plates, your batteries WILL be damaged. I remind myself to do this by performing maintenance on the solstices and equinoxes--quite appropriate for a solar energy system!
Equalize your battery bank 4-6 times a year. Don't do this with gel cells, only with regular "flooded" lead-acid batteries. Equalization is basically a controlled overcharge that extends your battery life by knocking deposits off the plates. It's usually easiest to do this with a generator. Charge the batteries at your normal rate, but don't stop when your meter shows full charge. Keep charging for 2 or 3 hours longer. If you care to monitor the process, you can take specific gravity readings 30 minutes apart and continue the process until the readings stop increasing.
4 times a year you should turn off the main power switch and::
- Check the electrolyte level. Do this when the batteries are -not- discharged, and wait a couple hours after charging for the hydrogen bubbles to disperse. The batteries should have full and low marks--sometimes the full mark is an inner plastic "shelf" with a hole in it to see the electrolyte level.
- Wear safety goggles and rubber gloves
- Fill ONLY with distilled water to the "full" mark
- DO NOT add acid!
- Clean the battery tops with rags dipped in a baking soda and water solution. DO NOT let this cleaning solution get into the batteries--be careful of the vent holes in the caps on each cell, as cleaning solution can enter the battery here.
- Check for corrosion on all the battery terminals
- If any terminals are encrusted in green "stuff" you should
- Make SURE your main power switch is off. If you don't have a main switch, turn off the inverter, all load circuits, and all charging circuits.
- Carefully disconnect wires from the dirty terminal and clean off the gunk with a wire brush. Don't breath in the dust! Wear a mask if neccessary
- Apply anti-corrosion paste to the terminal (available at any hardware store in the electrical departemnt)
- Reconnect the wires
- Relax and smile. Enjoy the fact that you don't have to read by candlelight anymore, or that you no longer pay bills to the power company! Your maintenance is done for the next 3 months.