Battery Voltage Test (Sealed Batteries Only)

- Turn headlights on high beam for 1 minute to remove surface charge.
- Disconnect battery Ground (GND) strap.
- Check battery positive voltage (B+) using SUN VAT 40 or equivalent.
- 12.4 volts minimum

Voltage % of charge
12.6 or more 100%
12.5 75%
12.2 50%
12.0 25%
11.7 or less 0%

If above the minimum voltage:
- Load test battery.

If below the minimum voltage:
- Charge battery (12.4 volts minimum).

Load test

NOTE: Before load testing, battery must be at least 75% charged.

- Connect load tester (Christie Automotive BT-900 or equivalent) according to manufacturer's instructions.
- Load battery to 3 times amp/hour rating or 1/2 0 °F cold-cranking current rating.
- Wait 15 seconds and read voltage.
Battery voltage at room temperature should be 9.6 volts minimum.

If NOT:
- Replace battery.

NOTE: If battery is colder than room temperature, voltage under load will be lower:

If battery must be tested cold, use chart below as a guide:

Approximate electrolyte Minimum acceptable voltage
temperature °F (°C) under load (volts)
60 (16) 9.5
50 (10) 9.4
40 (4) 9.3
30 (-1) 9.1
20 (-7) 8.9
10 (-12) 8.7
0 (-18) 8.5