Cummins/Onan — Battery Charge Rate Adjustment
Maintenance · Battery charging circuit
From a Cummins/Onan owner's manual — check it applies to your exact model before use.
Applies to: Cummins/Onan YD series, Cummins/Onan J block (Series JB/JC) engine
Before you start
- Batteries emit highly explosive hydrogen gas. Never smoke near a battery, and keep sparks, flames and other sources of ignition away.
Procedure
- Locate the battery charge rate adjusting resistor in the outlet of the generator cooling blower.
- Shut down the set before adjusting the slide tap.
- Adjust the slide tap up to increase the charge rate if necessary to maintain a specific gravity of at least 1.260.
- Keep battery terminals clean and tight; apply a light coat of vaseline to retard corrosion.
- Fill the cells with distilled water to keep the electrolyte level up to the split rings.
Specs & values
- Factory charge rate about 2 amps; specific gravity at least 1.260
Full service-parts list: Cummins/Onan YD series →
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.