- Full Size Hydrometer Battery Tester
- Larger Print Easier To Read
- Glass Construction For Commercial Applications
- Professional Quality For Highest Accuracy
- Precision Graduated Specific Gravity Float
Temperature Correction
Specific Gravity of acid is temperature dependent. If the temperature is very cold or very hot this can lead to incorrect readings. To correct for temperature use the following equations the equations or below 70ºF subtract points (0.03 per 10ºF) and above 70ºF add points.
Correction factor = (0.331 x Cell Temp ºF - 23) / 1000 or 0.003 pts per 10 ºF
Correction factor = (0.595 x Cell Temp ºC – 12.5) / 1000
This is valid for 0-130ºF or -17.8- 54.4ºC
The following shows the approximate state of charge at various specific gravities at 77ºF / 25ºC.
| Charged | Specific Gravity |
| 100% | 1.265-1.275 |
| 75% | 1.225-1.235 |
| 50% | 1.190-1.200 |
| 25% | 1.155-1.165 |
| 0% | 1.120-1.130 |
Hydrometers are at best accurate to +/-0.005 points. Voltage can be used to estimate state of charge, however caution must be taken when interpreting voltage readings.
Warning: This product may expose you to chemicals including lead which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov