The charger measures the battery's overall resistance rather than its internal resistance. Thus, it isn't a 100% accurate indicator of battery quality. Generally speaking, if a new battery shows "poor" resistance in the charger, try the steps below:
- Wipe both ends of the battery with a clean, dry cloth.
- Clean the charger’s channels and contacts.
- Move the battery slightly to ensure proper contact with the charger when installing it.
- Cycle the battery 1-2 times (charge it fully, use it partially, and charge it again).