Routine Battery Maintenance
The basics of routine lead-acid industrial battery maintenance.
Maintenance of correct electrolyte levels in lead-acid industrial batteries is important to the health and longevity of the battery.
This photo shows the correct electrolyte level that should be maintained.
The battery manufacturers' recommended fill level for flooded (wet cell) lead-acid industrial batteries is shown in this illustration.
Their owners manuals instruct that the battery should be checked and filled at the end of the charge cycle.
At the end of the charge cycle (within a few minutes of the charger shutting off), the electrolyte is at its highest level due to the expansion of the liquid that takes place during the charge cycle when the electric current is flowing through the cell.
When filling batteries at this particular time, filling to the manufacturers' recommended level which is 1/8" below the bottom of the vent well in each cell, is proper.
Filling to this level when the fluid is at its maximum height due to expansion will not cause the fluid to over-run out of the top of the cell due to expansion during the next charge cycle.
However, many operators cannot schedule themselves to be available to check and fill the battery cells at this exact time at the end of the charge cycle when the electrolyte is at its maximum level due to expansion.
Thus, the compromise is to fill as per our recommended procedure shown below.
Neon's recommended fill level for wet cell (flooded) lead-acid industrial batteries varies from that of the battery manufacturers.
Since many, if not most operators, cannot schedule themselves to check and fill battery cells at the end of the charge cycle (within a few minutes of the charger shutting off), it is appropriate to have an alternative fill level that can be used when filling cells at any time, that will both maintain a sufficient level of electrolyte for proper battery operation and will insure that the cells do not over-run acid out onto the top of the battery during charging due to the expansion of the electrolyte that takes place during charging.
This alternative fill level is shown in the photo.
For best results, we recommend using a battery watering gun with automatic shut-off feature for fast, safe filling of battery cells to the proper level.
See our Battery Equipment section under the Material Handling tab for pricing for the WG-1 watering gun.
Do not use battery watering bottles that are typically used to fill automotive battery cells. These battery filling bottles do not have an automatic shut-off valve and they will overfill the cells.
These battery filling bottles that can be purchased at auto parts stores are fine for filling automotive batteries which do not deep discharge under normal operation and which do not use much water.
However they should not be used to fill industrial battery cells unless you take care to frequently stop, remove the spout from the cell, and check the electrolyte level in the cell. If you insert the spout into a cell and let the water run out of these bottles until it stops, you will have overfilled the cell!
If your battery has corrosion growing around the edges of the tray and between the cells, it is highly likely that you are over filling your battery's cells.
If you add too much water to the cells, filling them up to the top, the next time you charge the battery, the electric current running through the electrolyte solution will cause the liquid to expand and it will spill out of the tops of the cells.
This will result in a growth of corrosion around the edges of the tray and between the cells which damages the tray and the cells.
This also dilutes the electrolyte solution by increasing the proportion that is water and decreasing the proportion that is sulfuric acid which results in a reduced capacity of the battery for storing electrical energy in a chemical form.
If the top of your battery starts looking like this; uneven or warped cell covers and tilted vent wells and vent caps, you are probably running your battery dry. Recharging a battery that is dry due to lack of liquid electrolyte, causes excessive heat during recharging which results in these symptoms. Extreme damage due to this excessive heat is evidenced by cell covers that are cracked open to expose the interior of the cells.
This kind of damage is extremely expensive to repair and usually requires replacement of the entire battery.
Keep the battery clean.
We recommend cleaning the battery and cables weekly when the battery electrolyte level is checked and when the battery is refilled. Cleaning the battery frequently prevents this job from becoming time consuming and protects the battery from a build-up of corrosion and dirt.
We recommend using an aerosol battery saver product that is formulated to neutralize acid and dissolve grease.
An industrial battery in a typical sit-down rider forklift truck costs between $5000 and $6000 (new battery). This is an investment that must be cared for in order to benefit from its full life expectancy.
Keep your industrial truck batteries charged and recharge them frequently even when the trucks are not being used!
If you store a battery or remove a truck from service for any reason, recharge the battery once per week in order to prevent it from sitting idle and sulphating the internal plates.
Sulfation is a natural occurrence in all lead-acid batteries. It is a primary cause of battery failure, even in relatively new batteries. It occurs when the sulfur in the sulfuric acid forms sulfur crystals on the battery's lead plates. These crystals act as an insulation, keeping the lead plates from reacting with the electrolyte solution and thus reducing the battery's capacity to store energy.
In order to prevent the accumulation of sulphation on the plates, it is important to have a disciplined battery charging schedule, even when the battery or forklift truck it is in, is not being used.
If your battery charger has an automatic start-stop function which is triggered by battery voltage, it may not turn on and run long enough to prevent sulphation of your battery. Contact your battery supplier for information on how to overcome this issue and insure that your battery gets a good recharge cycle at least once per week.
One solution is to purchase a small 110-volt AC charger with DC output voltage matched to your battery and with a manual timer so that you can control the On/Off cycle and force the charger to run and supply current to the battery even when it is fully charged. This will help to prevent sulphation of the battery.
Keep vent caps on the cells and keep flip-top style caps closed during battery charging.
This prevents battery acid (electrolyte) from splashing up out of the cells and onto the top of the battery and the cables during charging as is happening in this photo. The top of the battery has wet areas around the vent wells where electrolyte droplets are accumulating.
During charging, the electrolyte, which is a solution of sulfuric acid in water, bubbles and splashes out of the vent wells and onto the tops of the cells and onto the cables unless the vent caps are kept in place and closed.
They are called vent caps because they do have vent holes in them to allow the gasses to escape while preventing droplets of electrolyte from splashing out. During charging, the electric current running through the solution causes electrolysis to take place which is the process by which the water molecules are split apart into the two gaseous elements of hydrogen and oxygen. These escaping gases cause the electrolyte to bubble.
The loss of water by means of electrolysis is why you must refill the cells occasionally to maintain the electrolyte at the proper level.