The ELECTROLYTE is
the needed ENERGIZER
of the BATTERY CELL!

The level of electrolyte acid inside the battery cell has to be checked at least once a month, more frequently in hot weather.

If there are removable caps on top of the battery, this means that the battery is not maintenance free.

Take the caps off and look inside to see if the level of electrolyte is below the top of the plates. If it is the case, this means that damage has already being done to the battery cells, the plates being bent due to overheat.

It is better not to let that happen!

In order to adjust the level of electrolyte acid precisely where it should be, you have to charge the battery first, since the electrolytes expand during the charging process.

However, do not start charging the battery if the level is below the top of the plates. In this case, add distilled water so the plates are completely submerged and then charge the battery.

If you fill the battery cells to the top without charging first, it can result in overfilling because with the expansion, the acid will bubble out.

When comes time to refill, you have to use ONLY distilled water. Tap or spring water contains mineral and chemical that will damage the battery.

Never add acid to a battery. Before proceeding, turn off all loads and charger.

Be very careful! Sulfuric acid must be handled with extreme care.

Wear eye protection goggles or even better a face shield, thick rubbergloves and apron as well.

Removing each cap separately, fill the battery just to the split ring built into the battery top for each compartment. Do not overfill.

If you do, it will overspill when gassing, due to a charge being applied. Replace the caps and the job is done. It is that easy!

It seems complicated but it is not. With time, it will just become a routine.

With wet cell batteries, an hydrometer is also a good tool to have since it measures the specific gravity of the electrolytes in each cell of the wet cell battery.

An amp meter can not tell you the condition of each cell but the hydrometer will. You can get a good temperature compensating hydrometer at a solar supplier for $30. It will be made of glass and it is not the one that looks like an anti-freeze tester which is a cheap model.

You understand that if the battery is sealed, you can not use an hydrometer and you simply use a voltage meter.

In the case of wet-cell batteries, checking the specific gravity of each cell after it is stabilized and rested is time consuming but an excellent procedure to follow to know exactly the condition of your batteries.

Here is a table that can serve you as a guide :

% of charge/ Average cell gravity

  • [100 %/1.265]
  • [75 % /1.225]
  • [50 % /1.190]
  • [25 % /1.155]
  • [0 %/1.120]

Finally note that you will have to replace the battery if:

  • you never achieve a battery charge more than 75% of its capacity and/or
  • there is constantly a difference more than 0.05 in specific gravity between the cells of the same battery.

OTHER TOPICS ( 5 total ) directly related to RV BATTERIES


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