| Standard specific gravity | 1.25 or higher at 20°C (68°F) |
| Standard voltage | 12.3 V or higher |
| Standard resistance | Below 1 Ω |
| Charging circuit without load | Standard current | 10 A or more |
| Standard voltage | 13.5 to 14.4 V | |
| Charging circuit with load | Standard current | 30 A or more |
| Brush length | Standard exposed brush length | 9.5 to 11.5 mm (0.374 to 0.453 in.) |
| Minimum exposed brush length | 4.5 mm (0.177 in.) |
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| Slip ring - Slip ring | 20°C (68°F) | 1.8 to 2.2 Ω |
| Slip ring - Rotor | Always | 1 MΩ or higher |
| Slip ring diameter | Standard diameter | 14.2 to 14.8 mm (0.559 to 0.583 in.) |
| Minimum diameter | 14.0 mm (0.551 in.) |