Good charger and weakening batteries

The location device does what it should, invite 26650 batteries. The LEDs indicate the charging status (red for "Loading" and green for "full"). The charging process can take even up to half a day, depending on capacity and charge state of the battery. The charger can be switched between 4,2Vund 3V, but so far only used the 4.2V version.
Although the two accompanying battery packs have the imprint of 5000mAh, this information is definitely on the high side, I'd felt this to max. 4000mAh classify but this was me before already aware are but a point deduction due to deception.

Addendum: The charger switches to the charging once the indicator light jumps up in green to trickle charging.