Cummins/Onan 4.0BGEFA261 OOL / 4.0BGEFA26100L — Battery Care
Maintenance · Starting battery
For the Cummins/Onan 4.0BGEFA261 OOL / 4.0BGEFA26100L, from the Cummins/Onan operator's manual.
Applies to: Cummins/Onan EM (SN5782U1G2RA) engine
Before you start
- Batteries give off explosive gases that can cause severe personal injury; do not smoke near batteries and keep all ignition sources away.
- Battery electrolyte can cause severe eye damage and skin burns.
- Do not disconnect battery cables while the genset is cranking or running.
Procedure
- Keep the battery case clean and dry.
- Make certain battery cable connections are clean and tight; use a terminal puller tool to remove cables.
- Identify cable as positive (+) or negative (-) before making connections; remove negative (-) first and connect it last.
- Wash terminals with ammonia solution or 1/4 pound (about 100 grams) baking soda in 1 quart (about 1 liter) of water; keep vent plugs tight.
- Flush outside of battery and surrounding areas with clean water.
- On non-maintenance-free batteries add distilled water to the split-level marker in each cell; add water, not electrolyte.
- Use a battery hydrometer to check specific gravity of electrolyte in each cell; charge if less than 1.215; stop charging at 1.260 at approximately 80° F (27° C).
- If the remote battery condition meter stays abnormally low or high, have the boat battery charging system serviced by a qualified mechanic.
Tools required
- Terminal puller tool Amazon
- Battery hydrometer Amazon
- Goggles, rubber gloves and protective apron Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Charge battery if specific gravity measures less than 1.215
- Stop charging when specific gravity reaches 1.260 at approximately 80° F (27° C)
- Minimum required battery cold cranking capacity 360 amperes above freezing; 450 amperes below freezing
Source: Cummins/Onan operator's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.