Nitecore UM20 not charging to 100%

It's a handy little charger this Nitecore UM20 and very portable, but unfortunately both slots (whether used singly or with 2 batteries charging) only charge to max 96% (with a variety of batteries, all newer) -- at least that's what it says on the lcd readout -- when I pop a battery into for example a Vamos, it reads a full 4.2v.

Recently did a google and found more than a few others having this problem, so as good as their reputation is I can't really recommend this charger -- any other members have similar problems with this or another Nicetcore charger? Is it safe to use as long as I take batteries out soon after they hit 96%?

 

the last 4% or so sometimes takes a while...I've never had any battery I pop into it not reach 100% but sometimes the last bit takes longer than I think it should.

 

Thx for the reply Talen...I'll try to keep them in even longer and see if they reach 100% -- but the fact that they're appearing to be fully powered when actually put into a device is worrisome, I don't want to overcharge them and risk a fire or the like. Some online suggested to change the USB charger that comes with it as it's not super quality but that didn't help.

 

I believe it has overcharge protection built in...not sure but I believe it lowers the current coming in as the battery fills up so that's why it seems to slow down as it gets close to 100%

 

that was my first thought, but if they dont want/think the batteries charged above a certain point then make that point show 100%. battery safety is still something that i am overly anal about
(pardon my Americanism). for good reason....

 

They do show 100% but the last 4-5% is a slower charge and it seems to sit but it does eventually get to 100%...at least that has been my experience with the charger

 

no worries man, Nitecore has a safety feature. I believe it does that so it doesn't overcharge the battery. I usually use up my battery stock and charge them overnight (i know that you shouldn't do that) and i don't seem to have any problems with my battery.

Here's a few pic of my battery stock XD

 

As a little follow-up on my OP, and out of fairness to the product, I have indeed been able to get batteries charged to 100%, it just takes quite a while for that last 4-5% as per Talen's posts above.