Boruit RJ-02 - using the built-in charger

Hi

Could somebody give me a tip or two about using the built-in battery charger of this excellent headlamp?

I see that the light goes red momentarily when I put the Micro USB plug in.

How long should I leave it in?

Might I harm the battery if I keep it charging for, say, 2 days?

Regards
F

The light should turn green when fully charged.

That’s good to know!

Thanks

Tried using the EBD-USB+ meter to monitor the charging of the Boruit RJ-02:

(battery is some unknown, but working good 18650 — I had previously tested this battery to be around 2300-2400mAh and 40-50mOhms IR on the MC3000)

Boruit RJ-02 charges at a peak charging current of around 0.60A, and terminates at around 0.09A (this is measuring the USB)
(it’s a bit on the slow side, taking 4.5 hours to fully charge the ~2400mAh 18650 ; I forgot to measure the end voltage, but I recall the RJ-02 charges the 18650 pretty close to 4.20v +/- 0.02v)

Capacity from the EBD-USB+ meter seems to match the capacity of the battery when tested on the MC3000.