Asking about battery charging and maintenance can be confusing because everyone has a slightly different interpretation of how it is to be done, which i will demonstrate here in my post ;o)
I like to use these rules of thumb when maintaining a battery and what i tell the customer. All of these things have been elaborated throughout this thread, lets summarize...

1) check the charge level and if 50% charge or less you can charge it. (this is a general rule and is something only YOU can figure out based on your forklift usage rate, you dont want to get caught with a discharged battery in the middle of a shift and have to resort to the afore mentioned 'opportunity charging' which is a no no. ;o)

2) before charging check the water level in ALL cells, make sure the liquid is covering the deflector plate at least, a dry plate means burning the cell if it is charged dry. ONLY add water AFTER the cool down cycle and NEVER overfill the cell, only fill to the base of the cap deflector ring which is approximatly 1.5" below the top of the cell opening inside the cell. Most of them have a slit down the side so adding water to the base of that slit will suffice.

3)only charge in a well ventilated area and only set the charge for normal charge (equalizing charging is only done every so often to bring the battery cells up to an even voltage and is usually done once every month under normal usage, an 8hr shift, this will depend on the usage of the truck though, heavy usage, multiple shifts, then it would require more equalizing charging)

4)the general battery charge rule is 8hrs runtime, 8hrs charge, 8hrs cool down (this is ONLY a general rule, no 2 batteries are the same so this vary's from battery to battery)

5) Never add water to a hot battery, the law of physics is cold water on hot materials = bad things happen , cell plates can crack or even worse case scenario is a thermo reaction can happen and the water/electrolyte can have a reaction and be forced out of the cell into your face.

6) elaborating on #5 , ALWAYS wear face shield and apron and protective gloves when servicing a battery. Acid is very caustic and will eat anything, even human skin, it is very painful too :o)

7) NEVER disconnect a charging battery, ALWAYS stop the charge or turn off the power to the charger before disconnecting the battery.

8) When adding fluid to a battery always try and use distilled water if possible, normal tap water will work but is dirty with minerals that can build up in the cells over time, distilled water has been proven to prolong battery life and is recommended but not mandatory. NEVER add electrolyte to any cells.

9) After adding fluid to cells(water) clean up any spillage, excess water on cells can lead to corrosion buildup. A clean battery is a happy battery ;o)

10) If you have any battery or charger problems you are unsure of please call your PROFESSIONAL battery representative for assistance, DO NOT try and service or repair any part of the battery or charger if you do not know what you are doing! This should only be done by a trained person.

Now i'm sure if i missed anything someone will chime in and add it but i just wanted to summarize the important steps here is all.


Hope this helps
enjoy!