Flooded Lead Acid (FLA), or Wet Cell batteries, require the highest maintenance of the three types discussed. The electrolyte levels must be checked by removing caps on top of the batteries.
A wet cell battery can be ruined by simply not maintaining proper electrolyte levels. If the water falls below the tops of the plates, they will sulfate at a very rapid pace. This type of sulfation is not only hard to remove, but will substantially reduce capacity!
Each time you open the caps you are exposed to the electrolyte. During an equalization charge it will bubble and splatter on top of the battery while the caps are off. When you check the specific gravity with a hydrometer you have the possibility of drops of acid getting on things you don’t intend them to. These arenot reasons to avoid the wet cell but just things to be aware of.
One positive about the wet cell is the ability to perform an equalization charge that can remove the sulfate crystals that can tend to build up on the lead plates. The downside is that the equalization charge is one more maintenance routine to conduct.
If the charge rate remains low over a period of time stratification of the electrolyte can occur. The electrolyte is a combination of acid and water. Because of this, if the mixture remains still because of an low charge rate at a low voltage for a period of time then the electrolyte will separate with the acid settling to the bottom since it is heavier.
Gassing, the point where oxygen and hydrogen gas begins showing up in the electrolyte, happens at about 2.3 to 2.35 volts in an individual cell. When gassing occurs, this will stir the electrolyte. An occasional charge to allow this stirring is good for the battery. This is not a big negative for the FLA, just something to be aware of.
The FLA seems fraught with problems. The truth is, they are probably the best storage solution for the average off grid system. They can be forgiving to a point and are not as delicate as the Gel and AGM’s when it comes to an overcharging. The cost and life cycle is also much lower than the alternatives.
Accepts higher recharge voltages and temperatures. Lower initial cost. Can be equalized.
Low Temperature tolerant
longer life if maintained properly.
Acid can spill if battery is ruptured or overturned.
More maintenance required.
Less tolerant of low temperature.
Gassing can cause corrosion of wiring, etc.
Must be vented or placed outside.
What Other Visitors Have Said
Click below to see contributions from other visitors to this page…
Dave Paterson Not rated yet
I have solar system with 4 solar panels of 235 watts each and 4 x 370 amp/hr L-16 batteries in a remote location. The supplier advised me to store the …