PV Gap

Anthony Said:

Do I leave caps off of the batteries for my backup solar system ?

We Answered:

It certainly sounds like you got a problem there. For water to be spilling out of the batteries they must be over charging. You say it's a back up system . If you aren't using them all the time, you shouldn't need to have them on charge all the time. If you have them on charge all the time then you should have a regulator in the circuit to shut down the charging system once the batteries are fully charged. Warning...In case you aren't aware , but the gas coming off a battery while charging is Hydrogen , so don't cause a spark if you don't want the whole lot to go bang if you are in an enclosed area.

Most batteries these days have some form of indicator to tell you what the water level should be. That can be a strip of plastic across the bottom of the filler hole or a tube of plastic that goes down into the cell with two fairly wide slots opposite each other. Fill to to the plastic strip or to the bottom of the tube. The slots up the side allow charging gases out without a boil over. Certainly does sound like you may have overfilled them.
If there isn't any level indicator, then so long as the water is above the plates will be fine.
Hope you haven't had that happen too many times. Every boil over you loose acid.
Here's a tip if you don't already know. If you have an acid spill dissolve teaspoon of baking soda per cup of water and pour it on the spill. Baking soda will neutralize the acid. Be sure not to get any in to the battery.

Alan Said:

Does anyone know of an inexpensive source for lead acid batteries? I need 3 dozen or more for a solar system?

We Answered:

if you get a cheap or over used battery, they may not work and your experiment will fail. Besides, you could get just 1 battery that holds as much as 36 batteries, what you need to specify is amp hours of storage and volts.

Eddie Said:

what is the advantiage and disadvantage of 12v and 24v battery bank for solar system?

We Answered:

The answer depends on the voltage of the stuff you intend to connect to the system. However, if you intend to use an inverter, go for the 24 volt system as the current flowing for a particular power is half that for a 12 volt system. High currents cause failures in electronics such as inverters, due to the heat produced also voltage drop in the cables is reduced using 24 volts. Go for 24 volts.