Hi, I just bought a VC4 charger. I have a brand new evva NCR18650GA protected battery. It kept charging in slot 1 after the display showed 4.2v for 30 minutes until I removed it. I put the battery in slot 4 just to check and it immediately read “full”. I have no other battery meter to read voltage but it seems odd that 1 slot will keep charging while slot 4 says the same battery is full. Is it normal for the charger to keep charging after the meter shows 4.2v or should it read full instantly upon the dial gauge hitting 4.2v?
No problem, the Samsung ICR18650-30B is a 4.35V cell. Good for testing chargers.
Your VC4 seems to have a serious problem, though.
The HKJ review at lygte-info.dk says it does a good CC/CV
From the OP — is it right to say this cell definitely was overcharged?
We know cells might show somewhat high fresh off the charger — but not that high, right?
And a cell that’s run down for a while and is at 4.25v — shouldn’t be that high, right?
Is there any way this particular charger can overcharge a cell, without there being a problem?
Yeah it’s good that the charger wouldn’t accept and try to add more charge to that. But how did it get that high voltage?
If not — I guess XTAR can tell us — XTAR, will you pay postage for Tumbleweed to return that charger to you?
Since he’s checked his meter battery, verified the charger is overcharging, and says it smells like something’s wrong — you really ought to look at it.
Not trust GB or BG to check it but actually get it directly to XTAR.
Tumbleweed, can you check what the postage would cost to return that to XTAR?
(I know it’s likely to cost as much as the charger, that’s why I’m nudging you and XTAR to arrange to get it to them at their expense — you’ve done everything to verify it’s a real problem)
And, XTAR, please be aware — your policy of “return to seller” works fine for people who buy in their own country.
I’ve had problems with several cells and a couple of chargers by XTAR — but I go through my local guy, MtnElectronics. He supports what he sells, and postage within the US is reasonable for me to return things to him.
Your policy means few if any customers will bother to pay to return a bad product to Hong Kong or China.
We know what customer support from BG and GB can be like.
Nobody wants to pay return postage from the USA to them — same cost to just junk the XTAR product and buy something else.
But XTAR needs to find out where problems arise.
International postage FROM western countries is terribly expensive.
If you do want to find out about problems — pay for returns in special situations like this one.
Otherwise your policy makes it unlikely you will find out about problems.
Until someone gets hurt, at least.
Please. Take it up with a manager at XTAR.
I’m just some guy on the Internet. That’s what I think you ought to do.
@light-wolff
take a closer look
He ran that battery for some time, and the charger didn’t recognize it because it was still 4,25V, after having been discharged, not charged.
I’m not done messing with this thing yet. I like a good mystery, and I’m trying to figure out what’s going on before I get all panicky.
I took it outside in a safe dry location and put four Eneloops in it this afternoon. They were only partially drained, from a radio that I’ve been using them in. They are relatively new and have been cycled (always as a set, since new, in a Maha C-9000) perhaps four or five times. They terminated pretty close to way they should, at 1.45 / 1.45 / 1.46 / 1.39.
As soon as I have some 18650s somewhat run down, I’m going to try it again. I don’t remember for sure, but I think both of the termination anomalies involved the left-side slot #1. I want to see if the problem repeats itself, when I’m home and free to watch it closely. I’d like to do a set of 4, at 0.5 A in all the slots, and then a pair using slots 1 & 4 at 1.0 A.
The ‘scorched electronics’ smell does seem more pronounced after charging the Eneloops. I guess I just want to make sure this wasn’t an isolated incident, and I want to make sure it’s the chargers fault and not the fault of a cell, or operator error of some kind. Finally, I don’t want to be slagging Xtar unfairly. To that end, I’m almost regretting opening my mouth in the first place. I should have done further tests before posting here. There are a whole lot of folks out there using these chargers with obvious satisfaction.
If it catches fire or a battery goes ballistic, then I’ll feel justified in addressing the matter with Xtar. Either way I’ll post what happens when I get to that point.
Is US based XTAR Direct an arm of XTAR or just a distributor?
If there is a problem you would think XTAR would be pretty keen to get their hands on this charger to see if it’s an isolated issue or if there could be a problem with an entire batch. Nothing destroys a companies reputation like a series of fires.
The Eneloops look low to me especially the 1.39. Are these fresh off the charger? Most of mine come off at ~1.48 on a number of different chargers.
The Eneloops were fresh off the charger, where they had remained for <\ 15 minutes after termination.
I think mine come off the Maha at about 1.48 as well, and usually quite even. The 1.39 cell was noteworthy, but at least nothing was dramatically out of line. None of them got more than modestly warm.
I should note that the VC-4, prior to this and with its first use, did charge a pair of older Trustfire ‘flame’ 26650’s and four brand new Vappower IMR 26650’s in a normal fashion. That was a month or so ago, but I don’t recall any anomalies. The ‘Flames’ have been unused since, and I just tested them at 4.11 v. (I do hope that name is not prophetic!)
I’m curious - does anyone else’s VC-4 have a quite a strong odor? I’m not sure if this is frying resistors I’m smelling or if it’s natural. Give your VC-4 a snort for me please, and let me know. This one is pretty pungent, and I think it’s worse after charging the Eneloops.
I got 2 LCD failures out of my 40pcs purchased this year. I have already forwarded my findings to vendor and received full refund for them. I did open them up for visual check but found nothing abnormal (e.g burnt components) this time.
Pretty much useless warranty because it will cost more to ship to China than the charger costs. Xtar has really disappointed me with their warranty service which is basically nonexistent. Currently have 13 Xtar chargers but only 4 have been used. Two of those four have stopped working, 50% failure rate. Buy a different brand, one that will last.
My Xtar VC-4 smells bad.
Also mine only charges 18650 batteries to 4.17v. I know it is better then overcharging, but is this good for the batteries?
Cheers
4.17v is great in my opinion. I did some tests with my hobby charger and the difference between 4.2 and 4.17 was only about 3% if I recall correctly. From what I understand the batteries will last longer and be happier when charged to < 4.2.
Can’t help you with the smell, it may just be burning off some residue from the manufacturing process, how old is the charger?
As for only charging to 4.17 volts, it’s GREAT for the batteries. As I understand it, the closer you get to max capacity per charge, the shorter the life of the battery. The flip side of this is that the less MAH’s stuffed into the batteries, the sooner they need to be charged. It would be an interesting long term experiment to see where those two graphs intersect. Number of lifetime charges vs hours of useful output vs end voltage.
hmmm, lets see, I’ll need a sponsor, a fleet of batteries, a fleet of chargers with precisely controllable end voltage, a couple dozen identical flashlights… Should probably have them all in integrating spheres to watch the light output…
Ok, thanks guys on the charging cutoff information.
The VC-4 smells bad comment was in regards to “Tumbleweed48” post asking for the snort test for the strong odor.
Cheers.
Mmm, Ive ordered 25 MC1’s… First time trying out XTar. Im feeling uncomfortable 
No problem with the MC1. Simple and effective. No frills.
Thanks! 
Hi guys,
I think I might have a related problem. I’ve bought a new Xtar VC4 and went on to charge 1 AA (I don’t remember the brand) that usually holds 1600 mAh, as tested with my other charger, the Opus BT-C3400.
The thing here is that the charger keep charging the battery until about 4600 mAh were show in the display… I was afraid it was going to blow away! The voltage was at ~1.45 but it kept charging and charging (the battery was very hot).
I left the charger working in a safe spot, went to sleep and found out the next day that it stopped around 4600 mAh @ 1.5 v. Should I worry about it? How could it be possible that it putted that much mAh into the battery and it didn’t blow up?
Please let me know what you think; thanks in advance.
BTW, it was a battery that started with the “0v revival function”, i.e., other smart chargers (as the Opus) wouldn’t even recognize it because of the low voltage that it had, so I used this function from the Xtar to charge it. I don’t know if this would have anything to do with it.
4600 mAh AA! 
That’ts so! 
Any ideas of what might have been going on?
Thanks.