Cummins/Onan — Battery Charging (Bench / Boost)
Maintenance · Batteries
From a Cummins/Onan operator's manual — check it applies to your exact model before use.
Applies to: Cummins/Onan DQFAA, Cummins/Onan DQFAB, Cummins/Onan DQFAC, Cummins/Onan DQFAD, Cummins/Onan QST30-G5 engine
Before you start
- Batteries should not be left on Boost Charge for extended periods.
Procedure
- Do not put a filled battery into storage without first giving the battery a commissioning charge.
- Give batteries a further charge every six months at the normal initial charge rate until voltage ceases to rise.
- If the charger has a Boost Charge switch, select Boost at intervals detailed by the battery manufacturer (normally every 6 months).
- Reduce the charge rate to normal bench rate if electrolyte temperature exceeds 43 °C (109 °F) or battery volts reach 15 V (12 V battery).
- At the end of charging, check electrolyte levels and restore if necessary with electrolyte of correct SG.
- Replace vent caps.
Specs & values
- Boost charge not exceeding twice the bench charge rate
- Electrolyte temperature not to exceed 43 °C (109 °F); 49 °C (120 °F) in tropical climates
- Battery volts not to reach 15 V (12 V battery)
Full service-parts list: Cummins/Onan DQFAA →, Cummins/Onan DQFAB →, Cummins/Onan DQFAC →, Cummins/Onan DQFAD →
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.