You’ve just been unlucky, I don’t ever put the batteries in my trustfire or ultrafire charger first, always switch on first then batteries in, shouldn’t cause any issue at all.
You only need to touch the live on anything electrical to be subject to a jolt, I got it last week from 3 phase on a car ramp, that was supposed to have been isolated by a pro sparky!!
tabs
These I4 chargers seem fragile when moved around, I’m wondering if a lot of these are counterfeit based on that recent video that showed counterfeit xtar products along with the I4 chargers that were clearly visible.
I took my I4 on flight recently in my carry-on luggage, seemed safe wrapped amongst my clothes and received no big knocks. I took it out and heard a rattle, after more shaking out fell a big almost 1 inch long dirty piece of bad solder and a resistor. Still seemed to work but I threw it out as I don’t want to take any risks. Really bad QA which makes me skeptical if it was genuine, even though it looked and worked well and even came with a warrenty card.
Hmm. . . I have yet to use my recently received i4. I hope mine isn't bad. If it is, well I got it 50% off so no big loss. Sorry Gords, I know it's frustrating.
-Garry
I’ve heard back, less than 24hrs to be fair, they said they can’t do much till their back in the office Monday, which I feel is fair enough, they did say they had to check the keeppower cells are acceptable, again fair enough, I have replied pointing out their Panasonic cells so should be ok.
We’ll see what happens. 
I Have had my v2 for a while now. Although it has probably only charged about 20 cycles on 18650’s and 10 cycles on 14500’s, it has been flawless everytime.
I always plug it in, wait for it to light up, and then insert cells.
The newer genuine ones should have the serial number molded into the box and it should match the number on the packaging, I also saw a labeling discrepancy where the charging amperage’s were labeled differently (My i4 w/molded correct number had .375a*4 and .750a*2 while I believe the counterfeits are marked a bit differently (ma perhaps?)).
Also what voltages was the wall voltage going in if you used the wall adapter? I would think that it might not really be able to handle 240v as well and be prone to failure if they cheeped out on the power supply. If that’s the case a 12v DC wall wart would fix that somewhat or cover the issue; check the spelling too since some fakes aren’t quite right on with the name ;).
My wall-buy’s one has seemed quite solid for now, I’ll report back if that changes. BTW I always turn chargers on and let them initialize first before putting in cells since some designs of chargers need a to be able to zero at the start before being used. They’re practically little cpus in most cases and not all of em can deal with having a cell in during start-up, heck I’ve had smart chargers flip out when I’ve done it before.
Tingling voltage is never good on a grounded setup but since I don’t have grounding in most of my house I’ve gotten used to it, don’t touch things where charge can build up or get grounded when the circuit isn’t, don’t touch metal exposed near sources, etc. Heck it could have gotten fried from esd if it got too bad (Charger isn’t grounded so this is always a possibility, really is always a possibility anyways.).
Just checked, its rated to 240v, no option for UK plug so I don’t see that using the US plug supplied and a travel adaptor should be any more of an issue than it would be for someone from the US coming here and charging their cells.
The serial number molded into the charger corresponds to the seriel number on the box. Other than putting the cells in and turning on, I can’t see that I did anything wrong, and I’m not impressed about feeling the tingle on the negative line, none of my other chargers, including cheap crappy wall wart chargers do that, that was what made me switch off AMD load the cells dead in the first place.
We are well grounded here (all the UK is) but the unit has no option for an earth connection being 2 pin input only.
Sorry, I really just think the charger is a faulty unit more than anything.
I’ll see what the supplier says come Monday, for now I think they will be reasonable about things but we’ll see.
Everything seemed legit, packaging, spelling, external physical condition, warrenty and other paperwork . Good call on the S/N, I just got a new one from the same local vendor so I’ll check it out. It was mainly the dirty sloppy 1 inch long solder “nugget” and resistor that fell out from inside that made me skeptical as I would expect more from sysmax QC, it wasn’t roughly handled so it must have been sitting in there loosely. Voltage wouldn’t be a problem because I’m living in Vietnam at the moment, same as China at the lower voltages with a typical Asian wall socket plug, not to mention I had been using it with flawless service for up to 5 months prior. After handling mine for a while I do think the I4’s can be a little physically vulnerable, I’m wandering if they’re getting damaged during shipping hence the reason for some of the issues people are getting.
Good call on this initialization thing Dobanodnao. Went into the file cabinet to find the manual for the i2 and initialization is indicated with a plug in/charger self-test/battery insertion recommendation.
gords1001, does it have the same info in your i4 manual?
I'm really tempted to try that with one of mine. :evil:
i gotta thank everyone here for warning me off this charger
It actually is a really good charger, and inspite of the issue I had I went and got another one immediately, I’d never go back to my cheap Chinese chargers after measuring voltage at 4.5A on one occasion. The I4 is great, maybe fragile or maybe some very good counterfeits out there, but when it works it does so flawlessly in my experience.
Well, the seller got in contact today, shipping the unit back for store credit, undecided now on ordering another i4 or some other charger, I shall do some pondering.
Un-case anyone was interested, it was fasttech I was dealing with, I’m satisfied with their c/s. Professional, quick to respond and quick to offer a resolution that suited us both. I don’t think you can say fairer than that.
That’s for AC voltage. It will use you for the ground. DC doesn’t function that way. These chargers take AC input, but they output DC current to the batteries. You definitely shouldn’t feel anything from touching one of the charging terminals. Unless something is wrong with the charger, which it appears was the case.
Nitcore makes crap
Try an accucel 6 from hobby king (i have an accucel 8)
I got mine from Sierra RC, there's a thread about it here.
Absolutely great company and they got it to me just 2 days after I ordered it. :D
Of another opinion, nitEcore makes good stuff 
The chargers on it’s way back to china. Given it blew up after charging two cells and in light of recent events. I wont be buying anything nitecore again. I already have a hobby charger so perhaps I should have a play with that and just get some more two bay chargers.
I had a brand new i4 arrive yesterday along with some new AW 18650 cells and a nitecore smilodon.
The i4 popped and let out the dreaded magic smoke within 45 minutes of charging 3 cells. :/