Onboard charging Ft03

LED Flashlights – General Info
1

I asked this question in the wrong place so decided to start it’s own thread. I have a Astrolux FT 03 with USB charging that takes hours to terminate charge after reaching .1 amp. My USB meter shows it starts out at 2 amps and decreases to .1 amp normally but after that it takes about 4-5 hours to end. The 26650 Shocki 5500 mah cell measures 4.15 volts at the end with with a DMM. I saw this same type thing happen with a Sofirn SC31B . I s this a common trait of onboard charging chips? Does it do any harm to the battery to trickle for so long?

2

Charging a fat 26650 can take some time. What you describe does not seem wrong.

All Li-ion chargers slow down once the cell is getting close to full charge and the last .1V does take much longer.

3

The same cell at the same charge current in my normal charger finishes up fast. Just seems these USB charge lights have a tendency to take forever, at least two of mine do. They get to the end then linger.

4

If you look at the charging graph on this review the current drops off at the last third, is yours doing this or going into constant voltage phase too soon?

https://zeroair.org/2019/04/13/astrolux-ft03-luminus-sst40-flashlight-review/

5

I have noticed that compared to an Xtar charger, most lights with built in take longer

6

I am going to charge a cell in it again and watch closer. That charge cycle in the graph is 135 minutes and it was at .4 amps for only about 15 minutes. Mine was at .1 amps for hours. The cell was at 3.8 volts to start.

7

Charged another cell in the FT 03. The cell was 4.1 volts at first so I ran the light on turbo for a few minutes to drop the voltage to 3.9. The USB meter showed the initial charge current to be 1 amp. It started dropping every minute or so until it reached .1 amps a hour later. Never seemed to have a CC state. 2 hours later , for a total of 3. the charger stopped. Again at 4.15 volts. So I guess it is not harmful to the cell but I would only use the USB charger in a pinch since it takes so long. The USB charger in my SP 36 works very well but the SC31B also takes forever to terminate. Seems to be a lot of variance in these on board chargers.