Guru
Joined: 11/02/2018
Location: AustraliaPosts: 3375
| Posted: 12:30pm 18 Jul 2025 |
More important than the internal resistance of the cells is the total series resistance of the charging circuit. Any voltage droop at the charger output is equivalent to series resistance.
Reqyiv. = (Vnoload - Vload) / Iload
As long as the shunt resistance is significantly less than the total it will have little effect on the reading.
If you are using a constant current charger the effective series resistance is almost infinite.
If you have a good millivolt meter you just need a shunt rather than a whole ammeter.
If you can accurately measure the resistance of one of the charging cables that could serve as a shunt, though accuracy will be affected by temperature.
Edited 2025-07-18 22:53 by phil99