Pinpoint Test B: Auxiliary Battery(IES) Condition Test

WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

Normal Operation and Fault Conditions
Battery condition is determined by measuring battery terminal voltage after a specific discharge current is applied for a specified time period.

Possible Sources
- Auxiliary Battery(ies)
- Wiring, terminals or connectors
Visual Inspection and Pre-checks
- Inspect wiring, terminals and connectors.
- Inspect the auxiliary battery(ies).
- Inspect the auxiliary battery(ies) mounting.
- Inspect high current BJB connections.

B1 TEST THE AUXILIARY BATTERY(IES) CONDITION

NOTE: If equipped, vehicles with an auxiliary battery(ies) must be disconnected in addition to the main 12 volt battery to remove the 12 voltage from the vehicle or vehicle damage may occur.

NOTE: Failure to fully charge the battery before retesting may cause false readings.

NOTE: Vehicles that are equipped with two auxiliary batteries need to be disconnected and tested separately.
- Disconnect and Remove the auxiliary battery(ies) and allow the battery to reach room temperature. REFER to: Battery Disconnect and Connect .
- Charge the auxiliary battery(ies) for 1 hour at 2 amps on AGM setting.
- After the battery is charged, Remove the auxiliary battery(ies)'s surface charge by connecting an incandescent (non-LED) test light for 5 minutes.
- Allow the auxiliary battery(ies) to rest for 15 minutes.
- Measure the auxiliary battery(ies) voltage.
Is the auxiliary battery(ies) voltage greater than 12 volts?

Yes RETURN the battery to service.

No INSTALL a new auxiliary battery(ies). REFER to: Auxiliary Battery .