I recieved mine today, a MKii, and I think it may be faulty. Tried to charge some brand new (still empty) protected Xtar 18650 batteries and straightaway found that only one channel would charge on the 1A setting. Switched to 500mA and all seemed to work ok but when the green light came on after a few hours (on the "problem free" channel) the battery charge only measures 4.07v. The battery in the channel that wouldn't charge when set to 1A measures 4.17v, which I believe is just right. Do brand new batteries take a few charge/discharge cycles to settle? Or could I have a dud charger? As always, any advice very much appreciated.
Check this out https://budgetlightforum.com/t/-/4032
Thanks humppa. I did a WP2 search just before posting the above and I saw that thread, but only read down to where it looked like Davx's old battery was the problem. These chargers seemed highly rated but maybe not so good after all. Very annoying. How is yours behaving now? What setting do you charge at? Btw, I bought mine from HKequipment @ $18.99.
This morning I charged 2 more brand new Xtar 18650s on 500mA setting. Had to fiddle about a bit before they started charging ok. One green light blinking, then it would stay on green etc etc.. Finally all seemed ok and one battery terminated at 4.17, the other at 4.15. Assume this is ok? Will discharge one asap and try the 1A charge setting. Might email HKe but I won't get my hopes up.
In 500mA mode only the right bay works, 1A both work but never(?) terminates the charge. Probably going to order Pila or some hobby charger soon. Don't feel like burning the house because of this...
"Don't feel like burning the house because of this..."
Precisely. It's a bummer though. Not like they're the cheapest chargers, where you might half expect problems. These did so well in the reviews. Maybe a bad batch? Ah well..
I'll do a bit more digging around; if I learn anything worth passing on I'll start a new thread, maybe PM you. Good luck finding a better replacement.
My charger is also faulty, however mine started to smoke. Here is what happened:
I received my wp2 II and my 2 batteries from Serena. Both batteries were received with voltages right around the 3.9 mark. One was 3.89 and the other was 3.87. The charging amperage selector was in position "1" for 500ma charging. I put one of the batteries in the left slot and the led started blinking green then red then green then red continuously. I tried reseating the battery but it still did the alternating blinking. I then moved the battery to the right slot and it just stayed green. After half a minute or so I switched the selector switch to "2" for the 1amp charging rate and the led turned red and proceeded to charge the battery with a proper termination voltage of 4.17 volts. After this battery successfully charged I tried the other battery, trying the left slot again. Same problem as before. It blinked green then red then green then red. I then moved the battery to the right slot and the light stayed green. So as before, I moved the battery to the right slot, but again the led stayed green. Now remember the selector switch was in the "2" position for 1amp charging rate. So I switched the selector back to "1" for 500ma but no dice, the led stayed green. Then I switched it back to 1amp charging and then smoke started to come from my charger. I immediately took the batteries out and unplugged it. About an hour later I plugged the charger back in with no batteries and both led's started blinking just red.
I emailed Serena asking for advice on what I should do regarding this charger stating that I might've received a faulty charger and that I would wait to hear back from her. I didn't hear anything back from her. I emailed her again 11 days later thinking my previous email might've been lost in the shuffle of the chinese holidays that were happening at the time and stated as much in the email giving her a break for possibly not seeing my email. Now the email was not demanding or accusatory in any way, if anything it was very polite and matter of fact that I received a faulty charger and that I will wait for her advice on what to do. I still haven't received a response. But here's the weird thing, a couple weeks later I decided to plug in the charger to try again to see if I would still get the flashing red led's, however, they stayed solid green. So I tried again with the same method I tried before where I was able to successfully charge that one battery, namely, have the charger at the 500ma selection, put it into the right slot, then change the selector selector to the 1amp rate. I haven't tried anything else as I'm afraid of this thing smoking up again and burning the house down. However, using this workaround it successfully charges and terminates at 4.17 volts. I'm still afraid some electronics got fried from the original smoking episode, and I keep the charger in front of me while charging, but its not a good feeling for my first li-ion charger to have something I know is faulty and not receiving any kind of response from the representative that sold it to me.
Just wanted to share my experience with this charger.
Thanks for posting jk3. Apart from the smoke(!) it sounds very much like my problem. Till now I'd been thinking that this was just a very annoying waste of $19, but your experience sounds downright dangerous; puts things in a whole new light.
Apart from the link in humppa's post https://budgetlightforum.com/t/-/4032, several other members have posted of similar issues with the WP2 ii, and that's just here at BLF. Makes me wonder how many got sold worlwide, a sobering thought. IMO the more people who report such experiences the better. This charger got so many good reviews that I'm sure a lot of buyers will feel perfectly safe just leaving batteries on charge overnight. To be fair, they probably will be ok, but these faulty samples are out there.
glad I passed on this charger..don't understand how my 2 chinese junk chargers are flawless after all this time, but a reputable company has issues..you'd think they would have better QC than a no name brand manafont charger..guess not..
Mine still has not arrived from manafont, but so far I have not read of a bad one that has come from there. So, I'm still hopeful. Ordered on nov 16th so should be here any time. I guess I really need to go out and drain some cells so that I'll have some "test subjects".
Update! It arrived and seems to be working properly.
I noticed the same issues. The WP2 II charger is either flashing red/green on some 18650s or takes more than double the time for a full charge cycle on the left channel (the one with USB out) than the right channel.
Trustfire 2.4Ah
---------------
[CH1]
Start: 3.50V
End: 4.21V
Duration: 8:30h (Canceled!)
[CH2]
Start: 3.24V
End: 4.19V
Duration: 4:10h
Trustfire 3Ah
-------------
[CH1]
Start: 3.43V
End: 4.21V
Duration: 8:00h
[CH2]
Start: 3.52V
End: 4.19V
Duration: 4:05h
I believe there is some (parallel) resistance that shouldn't be there. Unfortunately, Xtar isn't so kind to provide a schematic (I wouldn't do it either), so you can rip out the USB part yourself.
Seems like the one to have is the older MK1 , or first model ...
I have to wonder if they tried to make the MK2 overly feature packed ...
Now ill have to pull mine out , and run it some more ...
I've been giving the Trustfire TR003 a serious work out for the last month or so , and so far no issue ...
Folks having issue [ especially smoke ] , how bout some pictures of the internals ...
There is a revised version of the MK2 now , so hopefully Xtar has fixed the problem , but now they need to address those who purchased dud chargers .
A revised version? Do you have any link?
I can take some PCB pics tomorrow.
WP2 II internals (thicker leads are not original 
):
Another question: Is this the TP4056 charger IC used for both channels (last pic, between the leads) ?
my wp2 II stopped charging on the right slot a few days ago, opened it up and the black wire was hanging loose with a speck of solder attached to the wire resulting in a cold solder joint. resoldered and all is good.
Nope it's 9926 ic (dual N-Channel MOSFET)
Charging ic is located near bottom right corner but has no markings. Even wide spread search for charging ic's with same leg count provided no results. Perhaps it's custom ordered or manufactured by some small unknown company.
but if I put battery (new or even fully charged) in to left bay, or try to charge two batteries, lights will go green-red-green indefinitely, or both lights go off, and no charge occurs.
Not a big deal. Just another lesson.
My no-name $6.00 chargers from DinoDirect all work fine.
I have the WP2 and so far, the batteries always come off between 4.2 and 4.21 (both sides).
I have WP2 first edition (in fact I have 2 but it doesnt matter :o )
I wonder what doest it mean when light blinks red-green-red-green.
This happened to me just now. I just measured capacity of one unprotected 18650 Ultrafire 2400mAh (blue), to 2,8V.
I pout it in the charger, and it started blinking, other bay, same thing. Several times same thing.
Than I put one other battery in one bay, it was red light as normal, and than I put that other battery in other bay, and finaly red bay as normal…
So, charger obviously refused to charge it for some reason, I dont know. Its very good charger, but not perfect 
It sounds like a bad cell to me.