Wuben C3 flashlight: built-in charging overcharges?!

Anyone tried the new Wuben C3 flashlight yet?

Just got hold of the Wuben C3 and tried some test.

I monitored the Wuben C3 charging the included Wuben protected 2600mAh 18650 battery. (connected a USB meter to check the USB charge current) -- at around 0.40A charge current (USB side), the indicator on the Wuben C3 will switch from 'red' to 'green', when I removed the battery and checked its voltage, it was around 4.13v with my DMM.

I reinserted the battery and continued charging it with the Wuben C3 just to check what happens. The USB charge current will continue to drop until around 0.15A (USB current) and then cuts off charging (USB meter drops to 0.01A), When I removed the protected Wuben 18650 and tested its voltage, I was surprised it charged to 4.31v ! (I immediately discharged the battery since this is over-voltage).

But I wanted to investigate further.. Knowing that this Wuben C3 overcharges, I tested another "used" unprotected 18650 battery (I know it's going to be overcharged, so I didn't use a new battery but a bit older one, that's still working good). Monitored the charge current (USB Meter side). Charge current didn't stop at just 0.15A but it continues to drop, I think it took about another 1+ hour, the charge current already dropped to around 0.07A, but apparently is still charging. Now this is gettting more suspicious, when I removed the battery, this unprotected 18650 battery already tested at 4.57v (!) with my DMM.

(I hope this old battery didn't get damaged too much, as I discharged the battery to below 4.20v immediately afterwards).

Now getting back to the Wuben included battery -- it would appear that if the C3 flashlight would have kept on charging the Wuben protected 18650 battery, were it not for the protection circuit that cut off the charge current. (to test this theory, I inserted the 4.30v Wuben 18650 to my MC3000 charger, and tried to charge it further (I set to LiIon4.35v so it can charge to 4.35v), and what happens is that the MC3000 will disconnect the charging when it reaches around 4.31-4.32v, which appears to indicate the protection circuit cuts off the charging when voltage goes higher than around 4.31v.

Now, if it had been an unprotected 18650, then the Wuben C3 would probably charge higher voltage (like the 4.57v, which I unplugged the flashlight from the USB power).

It's NOT SAFE to charge with the built-in charging of the Wuben C3, as it SERIOUSLY OVERCHARGES. (or one should monitor that once the indicator turns green, immediately unplug the C3 flashlight from the USB power. Leaving it "charging" continuously will charge to TOO HIGH voltage.

I hope this may only be a fluke with the charging of the Wuben C3 unit that I got. Can someone else who has the Wuben C3 verify? (try charging an unprotected 18650 battery), and leave the flashlight charging even after the indicator already turns green).

I ran a test after reading this thread. Yes, my C3 also over charged stock battery to 4.29V.

My quick test setup:

XIAOMI powerbank > USB Tester (automatically cut off when current draw is low) -> Stock USB-C cable -> direct charging ABE2600C 2600mAh stock battery inside WUBEN C3 (start @4.07V till end @4.29V).

4.57V!! At that voltage they might as well just connect the battery with the USB input…

It does not surprise me. I would say it is more common than we realize among the Chinese brands who are racing to the bottom.

Anybody selling $20 lights with charging and included 18650 cell - I have serious concerns about corner-cutting.

4.29v is likely the over-voltage cut-off protection of the Wuben protected 18650…

Would you be able to test using an unprotected 18650 (use a battery that you’re OK with overcharging…)?

I have tested other Wuben flashlights charging: Wuben L50, Wuben LT35, Wuben TO46R = they charge and terminate properly, some slightly less than 4.20v or just slightly over (I think like 4.14-4.23v, tested charging using unprotected batteries, not just the “protected” batteries that Wuben flashlights come with.)

I suppose we need to report this serious overvoltage to Wuben?

(the light indicator on the Wuben C3 turns green at about correct voltage, but leaving it still charging will charge to the too high voltage…)

In this case, perhaps Wuben should send with the light the special Samsung (ICR?) cell that normally takes 4.35v as limit! :person_facepalming:

I used to have those batteries but can’t remember its exact model designation.

You mean like the Samsung 28A? Those are certainly not designed for use in a pocket rocket.
Bought a couple for use with a UV-led with rather high Vf.

hello, its my video of C3, please welcome

Wuben recommend to use “only” protected batteries to charg with built in charger

While that may be true (using only “protected” batteries), I have tested a few other Wuben flashlights, namely Wuben TO46R, L50 and LT35 and both flashlights also come including with a Wuben protected 18650 — however, the L50 and LT35 do not overcharge batteries — I tried charging unprotected 18650s in these 3 other Wuben 18650-flashlights and they checking the battery voltage after charging, they are around 4.20v or a bit less — unlike the C3 which continues charging when the user does not unplug the flashlight from the USB power. Also, 4.57v (could have been higher, since I unplugged after about 2 or 3 hours after the C3’s charge indicator light turns green) is definitely too high for 18650 batteries.

I suspect some people will charge overnight and may not be able to monitor the charging state, and overcharging would not be good then (if they use an unprotected 18650 on the C3)

That’s really bad. I eyed it when it was on sale, I’m glad i didn’t buy it.

I ordered it and so far, haven't tried charging another battery without protection. I did observe that the green LED comes on at 4V and when the battery was at 4.18V, the charging current was at 0.002A.

Is there a tear down of the Wuben C3?

I didn't let mine charge that long but I can confirm the problem too. The voltage on the DMM is taken directly from the battery after charging with this light.

As ordered in pictures (V, charge rate @ time):

4.38V, 0.116A @ 9:02PM

4.43V, 0.08A @ 10:15PM

if you are removing the battery and adding wires to measure things, that may be throwing the charging off

also if you stop and restart a cycle (esp when it is finished) that may throw it off also

maybe what it really wants is to
a. start with a discharged cell (somewhat)
b. charge from there to 4.13V

if you restart it already at 4.13, that might throw it off

but it should always be checking for 4.20 and never go over that

if you have extra wires, that may uncalibrate the voltage or current readings it is taking during the cycle.

4.52 volts!
Yikes.

First time I tried to charge in flashlight since I got it.
Purchased Nov 27, 2020

It is going back to Amazon.
I’ll try another one as do like the light.

New stock is supposed to be fixed.

Thank you for your time and effort to run a C3 report. I just found this thread on the comment of my WUBEN C3 30% off deals.

Our tech guys has fixed the overchage issues and sqare spot after getting the feedbacks from customers. Stocks now in Amazon

is the new version C3 that do not has overcharge issues and already update the TIRE to has a round spot.

Links to access: https://amzn.to/38EnK7G

A lighting deal is coming in Dec 26th to save 15% off. Additional coupons might show up too.

That’s good to hear. Would be interested to re-test the Wuben C3, but I’m unable to order from Amazon…

“… the TIRE to has a round spot” What does this mean?

The spill with the previous TIR has a square shape... more like 3 corners and a rounded 4th. The spot is round and nice. I should take a picture...

I have a new one inbound for Monday.

Still confused on that comment.

I have a C3 bought about 6 weeks back. Guessing it’s got this over-charge “feature” :smiley:

I do like the light though (despite the 2600mAh “protected” battery- wass’up with that?). Still a nice throw for it’s small form factor. I’ll just charge via the Zanflare Vs. the internal USB port anyway. Also prolly’ use a Q30 or something a bit more modern battery wise.