Specific Gravity Check
- Read hydrometer and thermometer indications at eye level.
- Use the chart below to correct your hydrometer reading according to electrolyte temperature.
HYDROMETER AND THERMOMETER INDICATION CHART
| 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 AND THERMOMETER INDICATION
| Corrected specific gravity | Approximate charge condition |
|---|---|
| 1.260 - 1.280 | Fully charged |
| 1.230 - 1.250 | 3/4 charged |
| 1.200 - 1.220 | 1/2 charged |
| 1.170 - 1.190 | 1/4 charged |
| 1.140 - 1.160 | Almost discharged |
| 1.110 - 1.130 | Completely discharged |