Test/Review of Charger Xtar VC4

[HKJ]

Did you ever test this charger with Xtar adapter, that seems to be a nice match for their charger given the higher voltage?

No, but I would also expect it to be a good match.

 

[bmwsancho]

MY VC4 had the exact same symptoms as stated in this thread - two 18650s in the outer slots, low charging rate. When I even touched the USB cable the rate dropped to 0.0A and the green lights came up (charging stopped) and the display showed "full". power cycling the device restarted the charging process.

The device was classified as defect and exchanged by the seller. The new VC4 is a lot better but still shows slow charging currents. One aspect I have noted is that when checking up on the USB voltage with a "charger doctor" the overall current going into the VC4 is about half compared to what the device is showing on the display.

I have tried iPad Air 2 charger, iPad 3 (12W) charger, Samsung tablet charger (I believe 2.1A) - all results are the same.

 

[voodoogreg]

MY VC4 had the exact same symptoms as stated in this thread - two 18650s in the outer slots, low charging rate. When I even touched the USB cable the rate dropped to 0.0A and the green lights came up (charging stopped) and the display showed "full". power cycling the device restarted the charging process.

The device was classified as defect and exchanged by the seller. The new VC4 is a lot better but still shows slow charging currents. One aspect I have noted is that when checking up on the USB voltage with a "charger doctor" the overall current going into the VC4 is about half compared to what the device is showing on the display.

I have tried iPad Air 2 charger, iPad 3 (12W) charger, Samsung tablet charger (I believe 2.1A) - all results are the same.

Interesting, I have an anchor iq 5 port that outputs whatever the device needs (up to I think 5.2 v @ 2.4ma) ill check my cable, but aside from being a little slow, I seem a get a full charge. VG

 

[ChrisGarrett]

Interesting, I have an anchor iq 5 port that outputs whatever the device needs (up to I think 5.2 v @ 2.4ma) ill check my cable, but aside from being a little slow, I seem a get a full charge. VG

I'm only a sample size of one, but my new XP1 Hummingbird won't charge NiMH batteries up at the 500mA rate, but it will at 250mA and li-ions will charge up at the 500mA rate.

My VC4 doesn't get used a lot, but I have used it to charge some NiMH batteries with high IRs and it works, albeit a bit slowly at 500mA.

It's that 1A rate that I can't seem to hit either with NiMH, although I need to double check this and then li-ion 18650s that have been well depleted. My two Sanyo 2600 FMs referenced above, did take 2200mAh worth of current before I fell asleep for a bit and they came off at 4.19 and 4.18, so totally within spec there.

I just don't see it on the display, or from my Xtar volt/current meter.

I can live with this and the XP1, since these USB chargers are more Zombie/SHTF back-ups for but I think that we're seeing a trend here and I need to fiddle with the NiMH side of things even trying only one battery/cell at 1A.

Frankly, as much as I love Xtar, my MP1S undercharges well below spec, so it's glitchy, my VP2 was recalled, my XP1 doesn't charge up at 500mA on NiMH batteries and now the VP4 might be pumping less than 1A's worth of current into two slots. My MC1+ and WP2 II are both stellar.

Chris

 

[ven]

Interesting Chiris ,mr bmw seems to be having similar issues to myself:thinking:

I am thinking 1 of 2 things here,early unit with gremlin maybe...........Or could it be possible that the charger is detecting cells past their best and lowering the charge rate(maybe too advanced i dont know but a very intelligent charger). I will try it on some fresh LG IMR cells when i have time! Iirc the 30Q charged issue free at the start with a nice 1a rate in bays 1+4.
Since then i have been charging cells that are used constantly,sometimes a couple of charges in one day of the same cell. Basically i am charging cells that are over 12 months old and seen 100s of charges(long shot but maybe resistance built up in cells and mr vc4 thinks lets slow this show down).

My vp4 has been spot on just like my vp1 and vp2, however i am only going off what it shows on the display which is a set rate(1a) and not a variable.

To help get to the bottom of this i need to get the vc4 and another xtar charger going at the same time with similar discharged cells............timed and see how long!

Greg could be right and it could be screwed

 

[ChrisGarrett]

Ven,

I'm running down some Duraloop Ion Core AAs and I'm going to fiddle with them, the VC4 and the Xtar v/c meter. I guess in the last month, I wasn't really looking to verify my VC4, until the other night with the 2 Sanyo FMs.

I've been using my Ruinovo power bank to charge stuff up, just to play with it and it now seems that its 2A INPUT charge port has gone **** up on me and I'm only getting 250mA (for 4x18650s,) so forever! The 1A port pulls 1A through the Xtar v/c meter, so I'm good there.

I realize that this stuff is cheaply sourced electronics, but I am experiencing some non-imaginary issues.

Chris

 

[ven]

Look forward to your findings Chris, with more time i will try my best to test mine tomorrow . Will try new and old cell comparisons and see if anything changes. I am sure that my vc4 was spot on at 1st,charging the 30q and LG cells at 1a issue free(99.9% sure). Only after a week or two did i notice the charge rate drop to .5a or even less at times. At the time i had some chargers set up next to me in the front room(to much displeasure of the boss).

I have been relegated to the floor area now thanks to spike the dragon!! :laughing: Still in my sight though

 

[Necromncr]

Hi!

I am new here and I want to thank you HKJ and others for all these great articles and reviews. I am slowly getting my feet wet with all of this and researching everything I can.

What I wanted to know is if I am reading and understanding these graphs right and whether I am comparing apples with apples. It seems that VC4 is undercharging NIMH batteries?

For example VC4 is charging eneloopXX to only 2000 mAh, while D4 is charging it to around 2300 mAh, and Panasonic BQ-CC16 NIMH charger to 2500 mAh.

Same for eneloopAAA, Xtar charges to 670 mAh, D4 to 810 mAh and Panasonic to 910.

And for eneloopPro, Xtar 2520, Panasonic 3350.

What is going on there?

 

[HKJ]

What is going on there?

Batteries looses capacity with age, i.e. you cannot always expect a XX or Pro cell to be 2500mA. The best way to see if a cell is filled is to look at the temperature track, when the temperature starts to raise the NiMH cell is basically filled.

 

[ChrisGarrett]

I don't know...I just depleted 4 Duracell Ion Core 2400mAh AAs down to ~1.09v-1.10v after a 20 minute rest and just pumped 2220mAh, 2345mAh and 2380mAh into 3 of them. Not all chargers measure things the same way.

My LaCrosse BC-700 seems to read about 10% higher than my Maha C-9000, with the same/similar batteries.

If you're not starting the 'charge' process with the batteries/cells at the exact same voltage and if you're not using cells/batteries that are in similar condition, you're going to get a variation anyhow.

Chris

 

[ChrisGarrett]

Here's what I'm seeing with my VC4, my Apple 12w wall wart and Xtar v/c meter:

1 Duracell Ion Core 2400 discharged down to ~1.10v, after a good rest.

Slot 1: After a 10 minute beginning, where I only pumped 10mAh into the battery, the meter began reading 5.17v and a .37A current. The VC4 was showing the 1A charging rate.

After an hour, the meter readings were the same and the VC4 showed 1A charging and about 670mAh. After two hours, the meter was 5.17v and .37A and the charger showed about 1350mAh. After 3 hours, about 2020mAh and the meter readings were the same.

I pumped 2220mAh into that battery, but didn't get an ending time.

This tells me that with one battery in slot one, the VC4 put about 670mAh per hour into the Duraloop and not ~1000mAh.

Just now, I finished two of the Duraloops, both around 1.10v to start and placed them in slots 1 and 4, for a supposed 1A charge rate.

10 minutes go by and 10mAh per battery, before things kick in. Basically the meter read 5.11v and .73A and after an hour, I had my ~670mAh for both slots. At 2 hours, the meter is the same and capacity doubled. 3 hours, we're holding steady at ~670mAh per hour and my final capacities were 2345mAh and 2380-85mAh and a little over 3.5 hours, however, in the last hour, the VC4 meter went down to .9A, so not exactly 1A.

I've just started the fourth Duraloop in Slot 4 and the meter's reading consistently with the single slot 1 numbers, which started this test out.

We really have to a) assume that the meter on the VC4 is fairly accurate and b) we need to time this and check things at hour intervals to get an idea of what our chargers are actually pumping into our cells/batteries.

Chris

 

[keithy]

Just a query about the backlight for people who also have this charger.

With mine, I've just started turning off the backlight by holding the CH button down for a few seconds when charging 4 x NiMHs. When checking laster to see if the batteries have completed charging, I've noticed that the backlight is turned back on.

Is this normal behavior? The manual says the backlight goes into a power saving mode after a while of no interaction, or pressing down for a few seconds turns off the backlight, but not that it turns back on by itself.

Just wondering if it could be my USB power supply or if it's normal for the VC4.

 

[ven]

Thanks for feedback Chris,interesting results there..........makes me wonder on other chargers too!

I did a simpleton test in comparison This time i used 2 sets of new LG H1 cells,bays 1+4 for the 1a rate...........guess what

1st 2 cells all the way till termination showing 1a(granted only what it shows on screen but not showing the 0.5a etc of past)
I only squeezed 200mah in the cells, but being the last part of the charge it showed no reduction even though the slowest part. On charge for around 1/2hr till termination.


Then i swapped for the other 2 LG H1 cells


Again issue free charging according to display



Older well used cells,again 1a showing where last time it dropped straight away

All 4 bays showing .5a which of course is spot on

Some new LG cells just started off


Will see over the weekend,will carry on using it as a primary charger(will be used up to 14hrs a day).

 

[HKJ]

1st 2 cells all the way till termination showing 1a(granted only what it shows on screen but not showing the 0.5a etc of past)
I only squeezed 200mah in the cells, but being the last part of the charge it showed no reduction even though the slowest part. On charge for around 1/2hr till termination.

From the first post in this thread: The current dial only shows the maximum charge current, the actual current is lower when the battery is in the CV phase.

 

[ven]

Thanks for the info HKJ, i will look back over again

 

[ven]

Just a query about the backlight for people who also have this charger.

With mine, I've just started turning off the backlight by holding the CH button down for a few seconds when charging 4 x NiMHs. When checking laster to see if the batteries have completed charging, I've noticed that the backlight is turned back on.

Is this normal behavior? The manual says the backlight goes into a power saving mode after a while of no interaction, or pressing down for a few seconds turns off the backlight, but not that it turns back on by itself.

Just wondering if it could be my USB power supply or if it's normal for the VC4.

Keithy,my back light stays on for the full charge duration.

 

[ChrisGarrett]

Just a query about the backlight for people who also have this charger.

With mine, I've just started turning off the backlight by holding the CH button down for a few seconds when charging 4 x NiMHs. When checking laster to see if the batteries have completed charging, I've noticed that the backlight is turned back on.

Is this normal behavior? The manual says the backlight goes into a power saving mode after a while of no interaction, or pressing down for a few seconds turns off the backlight, but not that it turns back on by itself.

Just wondering if it could be my USB power supply or if it's normal for the VC4.

IME, there are three levels to the backlight: fully on, dim and off.

It seems to me that if something happens, like a battery finishes charging, or a fresh cell is inserted, when the display is in the dim position, or even off, it will pop back on and then go into the 'dim mode' after a minute, or whatever it is.

Chris

 

[Necromncr]

Batteries looses capacity with age, i.e. you cannot always expect a XX or Pro cell to be 2500mA. The best way to see if a cell is filled is to look at the temperature track, when the temperature starts to raise the NiMH cell is basically filled.

But you tested Xtar VC4 only one month after Panasonic BQ-CC16.

 

[JohnSmith]

Does everyone find their VC4 voltage meters to be accurate? Mine seem to read high with lithium ion cells. Cells reading as 3.8V with my multimeter appear as 4.0V in the VC4, and cells at 4.0V max out the VC4 meter reading at 4.2V. Anyone else experience this or know what may be happening in my charger?

 

[keithy]

IME, there are three levels to the backlight: fully on, dim and off.

It seems to me that if something happens, like a battery finishes charging, or a fresh cell is inserted, when the display is in the dim position, or even off, it will pop back on and then go into the 'dim mode' after a minute, or whatever it is.

Thanks Chris (and Ven). It does seem like that's whats happening. When the display backlight is set to off, it comes back on when battery finishes charging. However, I've been testing my various USB power supplies with this charger, and found that on my Poweradd 25W http://www.ipoweradd.com/poweradd-2...ne-6-6s-5-5s-4-4s-ipad-tablets-psp_p1311.html 2.1A socket it was showing some weirdness with 4xAAs. It was only charging all four 2300mAh NiMHs at 0.1A.

And when it completed and the CH# leds were green, the backlight did not come on, but it only reported adding 470ish mAh into all cells. All cells were depleted, so it should have added at least 2000 mAh. I unplugged from the Poweradd, and used an Asus 2.1A charger, and three of the cells then charged up an additional 1500ish mAh, while the last one added just over 2000mAh.

The poweradd 2.1A socket had no problems charging an iPad at full rate, so it seems that the VC4 is really fussy about the USB power source.