Xtar VC4 doesn't know when to quit!

Batteries and Chargers Chargers
1

After running an Olight S20 for an hour or so last night, I popped the battery (a Samsung ICR18650-30B) into my almost new Xtar VC4. The charger refused to recognize it, although it readily recognized and started charging a Panny 18650B out of another light.

I put the Samsung into a Nitecore i4, and again, no recognition.

Puzzled, I checked the voltage on the Samsung and was surprised to find it at 4.25v! I then put it into an old cheapo 501b to run it down somewhat (out on the deck!) thinking that if it was wanting to have a runaway and popped it’s cork it wouldn’t be doing much damage. Checking it later, it was down to 4.10 and seemingly still healthy, so I ran it down to 3.89 without incident.

Puzzled, I went back to the Xtar and saw that the channels in use (I had later added another cell) showed 4.20 v and were still charging - I popped out the first Panny 18650B I had put in and was shocked to find it at 4.49 v. I have no idea where, or if, it would have stopped, and I don’t know how overcharged that Samsung might have been when I pulled it out of the charger in the first place - but after a good run it was still at 4.25, so it must have been right up there. I suspect I seriously shortened the life of two otherwise very good 18650s.

I won’t be trusting this charger any longer. I guess the moral of the story is, don’t go trusting a charger at all! For now, I’ll go back to the old Nitecore and run it out on the deck when possible. At least the Nitecore always knew enough to stop at 4.18 v.

Any recommendations on a better charger?

2

Can you afford to return that to whoever sold it to you?
Xtar says the reseller handles warranty claims.
I’d sure like to know what they say.

3

I suspect it’s hardly worth it. The postage back to the seller would be more than the price of the charger. I probably just got a bad one, but it scared me all the same.

I don’t doubt I could still use it, but I’d have to watch it like a hawk and take the cells out as soon as it showed 4.2 v. I think the safest thing to do is to chuck it.

4

For safety’s sake we should probably always charge outdoors or in ammo boxes in the garage. Realistically most of us (myself included) aren’t going to do that because it’s just inconvenient. I’ve compromised by carefully watching/checking voltage the first few times I use a new charger, and then periodic checks after that. My charger is in my office, but it’s in a steel cash box with vents in the top that won’t protect me from the fumes of course, but the idea is that it might contain any flying parts or flames. In reality it probably wouldn’t do anything, but it gives me a little more peace of mind.

Anyways your case is troubling. Xtar usually has great chargers, and I’ve never seen a name-brand charger over charge by that much. I’m glad you didn’t experience any physical harm.

5

I don’t know it it has any significance, but I just checked the voltage across the contacts of the VC4 and got 4.64 v. on all four slots.

The Nitecore i4 showed 5.23 v. on all four slots.

6

You might ask around whether there’s anyone within cheap postal range (local to you, I guess) who could crack the thing open and identify the problem.
Just in case anyone’s curious.

It’s sure cautionary for anyone else with that charger.

7

Have you checked your DMM battery?

8

I’m still trying to wrap my head around the technical side of charging, but I believe some chargers have a high no load charge voltage.

9

+1

10

Regulation is measured and (hopefully set properly) under load; almost every charging circuit will read higher when unloaded. Measure while in use for the truest readings. I use an Xtar VC2 (no “+”) which is likely very similar inside so I’m watching this thread with care and concern. I charge here on my desk with it in sight and I read it’s display as well as feel the cells for heating every few minutes. The front door is 4 steps away if I need to toss it. The displayed voltage measures accurately with 2 different cheap DMM’s so I believe the numbers but I treat it like I would a known thief anyway- I don’t trust it out of my sight for a moment and I verify what it tells me. So far so good but if a problem is possible I want to know about it.

Thanks for the thread and do keep us updated!

Phil

11

Xref, see (earlier today I suggested XTAR ought to pick up return postage for verified serious problems)
But check your voltmeter battery first. (Several of us will admit to having been fooled by DMMs with weak batteries reading too high or strangely)
If it’s verified real, now I’m just some guy on the Internet mind you, but I’d suggest leaning on them — tell them they ought to pay return postage so they can find the problem.

12

Well, I put a fresh battery in my main DMM, which is a quite a good one, and all my numbers matched the original tests. (The original 9 v battery in the DMM tested 9.13, the fresh one tested 9.41.) Went out to the shop and fetched one of my other DMMs, and again, the numbers matched.

I think I just got unlucky. It’s understandable that out of thousands of copies of any product, a small number are bound to fail. That’s why there are warranties. Unfortunately, when the warrantor is on the far side of the planet it doesn’t really mean much. It’s really no big deal, they’re not a fortune to buy and my house didn’t burn down. At worst, I shortened the life of a couple of 18650s.

It’s too bad Canada Post is such a rip-off outfit, or I’d send it back. ( I don’t even remember if I got it from BangGood or Gearbest!) Postage from here is outrageous. It’s not that I can’t afford it, it’s just that it pisses me off to no end. My cheapest alternative is to just buy a new one. Everybody else seems to be having good luck with them, and the chances of getting two duds in a row are slim to none.

It did have me scratching my head, though. I just gave it a sniff, and it seems to have that lovely ‘cooked electronics’ fragrance to it, although it still lights up and charges. Basically, it works perfectly if it would just terminate when it was supposed to. Kind of an important part of the charging process, it seems to me. I’ll have to get one of my electronically minded buddies to dig around in this one and see if he can figure out the fault just out of curiosity.

The reliable old i4 will do the trick until I get a new bells and whistles ‘something’. I’ll be a lot more careful how and where I do my charging from now on, and there’s the lesson.

13

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?

14

No problem, the Samsung ICR18650-30B is a 4.35V cell. Good for testing chargers.
Your VC4 seems to have a serious problem, though.

15

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.

16

@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.

17

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.

18

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.

19

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.

20

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.