Here are my standard procedures when servicing batteries.
1. Remove all rings and jewellery. (A short from a terminal through a tool, through a gold wedding band, to the other terminal can burn your finger off in short order, let alone make a loud snap, blinding light, whoof of ozone, and possible injure you when you recoil.)
2. Turn on battery compartment area ventilation for a few minutes. (Bilge blower, opening ports
, etc.) This will help purge explosive gases.
3. Disconnect all loads and charging sources. (Eliminate spark on terminal removal
4. Wear old clothes, goggles, and rubber gloves.
5. Open battery boxes, remove insulating terminal covers, and check terminal for tightness and corrosion
. (If you can twist the terminal by yanking firmly on the cable, it is too loose. If there is any sign of corrosion
, remove the terminals, and clean.)
6. Clean battery tops with a paper towel and dispose in plastic bag. (If wet, neutralize with baking soda, and keep handy in case of a spill.)
7. Check bottom of battery box
to ensure there is no liquid. (If there is, slowly pour backing soda down the sides before removing the battery, to neutralize the acid.)
8. Remove all traces of baking soda before next step.
9. Remove caps and fill with distilled or de-ionized water (one cell at a time, unless caps cover all cells). Fill just to the bottom of the slats (with slits in them) that protrude down.
10. Return everything back to normal and turn the charger
11. Bring the battery up to full charge, remove all charge sources and put on a small load (some cabin
lights) for 10 minutes.
12. Check the battery voltage. (Should be 2.15Vdc per cell +/-0.05 volts/cell).
13. Perform a load test. (Special tester.)
14. When all is well, reinstall terminal and battery box
covers. (Ensure battery boxes are secure and can withstand a knockdown and turtle.)