Specific Gravity Check
- Read hydrometer and thermometer indications at eye level.
- Use Hydrometer Temperature Correction to correct your hydrometer reading according to electrolyte temperature.
Hydrometer Temperature Correction
| Battery electrolyte temperature °C (°F) | Add to specific gravity reading |
|---|---|
| 71(160) | 0.032 |
| 66(150) | 0.028 |
| 60(140) | 0.024 |
| 54(130) | 0.020 |
| 49(120) | 0.016 |
| 43(110) | 0.012 |
| 38(100) | 0.008 |
| 32(90) | 0.004 |
| 27(80) | 0 |
| 21(70) | -0.004 |
| 16(60) | -0.008 |
| 10(50) | -0.012 |
| 4(40) | -0.016 |
| -1(30) | 0.020 |
| -7(20) | -0.024 |
| -12(10) | -0.028 |
| -18(0) | -0.032 |
Hydrometer Temperature Correction`
| Corrected specific gravity | Approximate charge condition |
|---|---|
| 1.260-1.280 | Fully charged |
| 1.230-1.250 | 3/4charged |
| 1.200-1.220 | 1/2charged |
| 1.170-1.190 | 1/4charged |
| 1.140-1.160 | Almost discharged |
| 1.110-1.130 | completely discharged |