I just purchased a wuben C3 and the onboard charging circuit charges the battery to 4.28v. I messaged Wuben about it and they stated that when fully charged the flashlight is around 4.3v, and that 4.28v is within the normal range. This seems kind of unsafe but I’m not too knowledgeable about battery voltages and would like to know what those of you more versed in these things think about this.
It’s not necessarily unsafe but will degrade the cell significantly faster.
As for Wuben reply, no that’s not normal.
I remember this model, there have been other reports of overcharging :
Particularly worrying is that the charge voltage is actually much higher and is only limited to ~4.3V by the protection circuit of the bundled cell.
This flashlight should absolutely not be used with an unprotected cell or there is a risk of fire.
I was actually just going to grab that link. This was supposedly resolved a long time ago. I wonder if the OP managed to find old stock somewhere.
Royce that is what I thought, but in that thread Wuben states that their amazon stock is the newer fixed models so I purchased off of amazon since I thought it was safe. I unfortunately don’t have any unprotected cells to test and see if it exhibits the same charging behavior as the old models. But then Wuben stated to me that full charge is 4.3v, which was demonstrated in that same thread to be the protection circuit cutoff voltage for the included wuben cell… 
Update: I decided to return it to amazon. I’m not going to take any chances since this was originally intended as a gift. Which is a shame since if not for the charging issues this would be a wonderful flashlight for non flashlight folk, with its dead simple UI, usb-c charging and good general purpose beam profile.
So you already knew this was an issue but you did not spell that out in the first post here.
I’m sorry which issue are you referring to?
You implied that you knew about the history of this model overcharging and that you bought it off of Amazon because you “thought” it was safe. When I read the original post I recalled that wuben had an issue with one of their models overcharging. I did not recall the model but suspected that it was the same one.
The bigger issue here is the response from wuben.
My “improved” second release has got their charging right.
So the amazon rep just contacted me back and said that the onboard charging circuit does have voltage cutoff. So at least there shouldn’t be a fire risk, I think. But it’s bizarre that they chose 4.3v as the cutoff voltage.
It’s just doubly bizarre that they would set the termination voltage properly to 4.2v, then later choose to up it to 4.3v.
Is it possible that their included 18650 cell has a 4.35v cut off? Some models are spec’d at 4.35v.
You are wrong on both counts. It seems clear to me that they intended originally to stop charging when the green light went on at approximately 4.2 v. The battery protection circuit was stopping things at approximately 4.3 volts. They never upped anything. We don’t know if wuben created the charging circuitry or if they sourced it from some other place. That’s still no excuse for releasing a light with that fault. My guess is that you got one from the first batch. Either it was sitting on an Amazon shelf somewhere or potentially even got returned at some point and was put back into the system. Does anyone know if any of the first batch were sold on amazon.com? This is partly why battery manufacturers say that consumers should not be handling individual batteries. And it’s mostly why larger flashlight manufacturers want to put protection circuits on batteries. But it still doesn’t excuse wuben’s charging fault. I can’t find any reference but clearly overcharged protection circuits on batteries are going to be somewhere north of 4.2v. 4.3v sounds reasonable.
Both versions were sold on Amazon.
Ordered my first version on Nov 23.2020
Second version ordered Dec 25, 2020
Still like the flashlight.