Cummins/Onan — Battery Care
Maintenance · Starting battery
From a Cummins/Onan owner's manual covering: E124V, E125, E140, Miller P216, Miller P218, Miller P220, Miller P224, P218, P220, P248. Check it applies to your exact model before use.
Applies to: Cummins/Onan E124V, Cummins/Onan E125, Cummins/Onan E140, Cummins/Onan HGJAA, Cummins/Onan HGJAB, Cummins/Onan HGJAC
Before you start
- Batteries give off explosive gases; do not smoke or allow flames or sparks near batteries
- Battery electrolyte can cause severe eye damage and skin burns
Procedure
- Keep the battery case clean and dry.
- Make certain battery cable connections are clean and tight.
- Remove the negative (-) cable first and connect it last.
- Remove corrosion with an ammonia or baking soda solution; flush with clean water.
- Add distilled water to each cell to the split-level marker if not maintenance-free.
- Check specific gravity of each cell with a hydrometer; charge if below 1.215.
- Stop charging when specific gravity reaches 1.260 at approximately 80° F (27° C).
Tools required
- Terminal puller tool Amazon
- Battery hydrometer Amazon
- Goggles Amazon
- Rubber gloves Amazon
- Protective apron Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Recharge if specific gravity below 1.215
- Stop charging at 1.260 at approximately 80° F (27° C)
Full service-parts list: Cummins/Onan E124V →, Cummins/Onan HGJAA →, Cummins/Onan HGJAB →, Cummins/Onan HGJAC →
Source: Cummins/Onan owner'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.