# Test/Review of Charger Xtar VC2



## HKJ (Nov 27, 2014)

[size=+3]Charger Xtar VC2[/size]















Xtar makes many LiIon chargers, this is a usb powered dual channel charger with display. The charger can charge with up to 0.5A for each channel, but the current is not user adjustable.



 

 

 



I got the charger in a small cardboard box with the specifications printed on it.






Inside the box the charger was in a small fabric bag, this can be useful if it is used as a travel charger.






The bag contained the charger, a usb cable, a warranty card and a instruction manual.






The charger is usb powered from a micro usb connector, but there is not a power supply included, i.e. you must supply your own usb power supply/charger. With a maximum charger current of 1A the charger works best with high power chargers, but will reduce its current if the power supply is overloaded. 
I have tested a few usb power supplied.






There is only a display as user interface, no buttons or switches.






The display uses dials to show voltage and maximum current, it does also have some 7 segment digits to show charged capacity.









The current dial only shows the maximum charge current, the actual current is lower when the battery is in the CV phase.
The voltage dials shows the actual voltage when in range:
0V Battery voltage is low, charger is only using low current, display may show "Err" if there is a problem with the batteries.
3.0V Voltage is high enough to start regular charge.
3.5V-4.2V Regular charge, display is within 0.1 volt.









The charger can handle both button top and flat top batteries.
The slider moves smoothly and can hand cells from 30mm to 71 mm long.






























The charger can handle 71 mm long batteries, including flat top cells.



[size=+2]Measurements charger[/size]



When charging the last digit in the capacity displays will flash.
The charger will charge with 2.4mA from 0 volt and display will show "Err"
At 0.2 volt it will start charging with 340mA (It will be down to 180mA 2.9 volt) at and display will show mAh.
At 2.9 volt regular charge current will be applied.
When charging two batteries with reduced current, they may not charge at the same speed.
When charge is finished the charger will charge with 0.3mA.
Charger will restart if voltage drops to 3.9 volt.
Charge will restart charging after power loss, or battery insertion.
When not connected to power it will drain about 0.1mA from a battery.
Current dial will show maximum possible charge current, not actual charge current.
Charge current steps down if usb voltage drops too much and may step up if usb voltage recovers (Like when one slot is finished).
Voltage dial will show within 0.1 volt when voltage is above 3.5 volt, between 4.1V and 4.2V is does also have a 4.15V position.
Voltage dial is within 0.1 volt when voltage is above 3.5 volt.
The 3 volt position on the voltage dial looks like it signals "start of regular charge", i.e. 2.9 volt.
mAh display flashes "Full" when the corresponding battery is full.
The background light will flash when at least one battery is full.

The light green line is usb current consumption, the dark green is charge current.






The charger does a nice CC/CV charge with a termination at about 50mA. There is some oscillation during the final part of the charge, but it does not affect the result.
The display shows 2918mAh charged into the battery.






The other channel has a similar result.
The display shows 2932mAh charged into the battery.






The 2600mAh battery has a very long CV phase, probably because it is getting old.
The display shows 2549mAh charged into the battery.






The 3400mAh takes slightly longer to charge.
The display shows 3254mAh charged into the battery.






The charger has no problem with my old IMR cell.
The display shows 177mAh charged into the battery.






The display shows 715mAh charged into the battery.






The display shows 784mAh charged into the battery.






Supplying a falling voltage to the charger shows that the current regulation works at around 4.7 volt. When the voltage gets below 4.7 volt the charger will start reducing charge current, until the voltage is above 4.7 volt again. If this does not happen the charger will stop completely.






To see the current limiter in function I put a 1ohm resistor in series with the power supply, this simulates a fairly bad usb power supply.
As can be seen the charge current is reduced, but the cell is fully charged.
The display shows 2791mAh charged into the battery with 0.3A current.






With two batteries and 1ohm in series with the power supply the charger has to limit the current even more. This shows that the two channels is not balanced, there is a significant difference in charge current (This cannot be seen in the chart). After 23½ hour the mAh count was 2088 and 2746. When the second cell finished (At 1500 in the chart), the first cell was charged at a much higher current.
The display shows 2846mAh and 2904mAh charged into the battery with 0.1A current.






With two batteries and a stable 5 volt power supply the charger will use about 500mA for each battery when charging.
The temperature raise is very limited.






M1: 24,8°C, M2: 24,7°C, M3: 27,4°C, HS1: 33,8°C
There is no doubt about where the heat generation is, but actual temperature shows that it is a insignificant heat generation.






M1: 24,7°C, M2: 24,3°C, M3: 28,0°C, HS1: 36,4°C






The charger needs about 6 seconds to start.






But if the power is limited it will use some more time to adjust the charge current.






The scope traces looks very smooth, but that is only because I filters them. The charger is using a unfiltered 62kHz charge current.






When current is reduced the charge will dynamically adjust the current.


Because the charger is supplied from usb power there will not be any safety issues with it, but be careful with the usb power adapter.



[size=+2]Conclusion[/size]

The actual charging is very good, but is a bit slow or very slow, depending on the usb supply used. The charger can draw a lot of current from the usb port, it will not be a problem with most usb chargers and power banks, but I wonder how a PC usb 2 ports will handle it.

The charger is a nice for car and travel usage and can also be used at home, but it is a good idea to find a power supply that can supply enough current and voltage for full charge speed. Remember to use a short cable between power supply and charger to avoid slow down due to losses in the cable.

I will call it a good charger.



[size=+3]Notes[/size]

The charger was supplied by XTAR for a review.

Here is an explanation on how I did the above charge curves: How do I test a charger


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## Timothybil (Nov 27, 2014)

Nice review. Looks like a nice charger for Li-ion, but no NiMH. Does anyone make a comparable USB charger for NiMH? My emergency power setup right now is all USB, and I need a way to recharge my Eneloops.


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## Aperture (Nov 29, 2014)

Good to know I bought a good charger, thanks for the review.


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## neutralwhite (Dec 18, 2014)

Where can this be bought in the UK ?.
any good place ?..thank you.


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## UnderPar (Dec 18, 2014)

Thanks for this review. Am keeping an eye on this charger. Seems to be a good charger for us to know the real capacity of our batteries.


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## HKJ (Dec 18, 2014)

UnderPar said:


> Thanks for this review. Am keeping an eye on this charger. Seems to be a good charger for us to know the real capacity of our batteries.



It does not measure the real capacity, only how much it fills into the batteries.
If you starts with an empty LiIon battery it will be fairly close to the real capacity.


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## KITROBASKIN (Dec 18, 2014)

If you often walk at night in a certain area for a basically the same amount of time (And you use the same mode settings), then you can determine about how many mAh your flashlight uses for that walk. This can help you gauge how long your light will shine to the ending state-of-charge you choose. That is, if you charge consistently each time. Handy



HKJ said:


> It does not measure the real capacity, only how much it fills into the batteries.
> If you starts with an empty LiIon battery it will be fairly close to the real capacity.


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## UnderPar (Dec 18, 2014)

Ooops, I stand corrected. Thanks HKJ


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## incd (Dec 19, 2014)

I don't have quality power supply for rate 5V, 1A. 

But I do have a good power supply rated 5V, 1.8A, is that ok to use it on this charger?


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## HKJ (Dec 19, 2014)

incd said:


> I don't have quality power supply for rate 5V, 1A.
> 
> But I do have a good power supply rated 5V, 1.8A, is that ok to use it on this charger?



It is perfectly fine. 
With current you can always use a power supply with higher current rating.


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## KITROBASKIN (Dec 19, 2014)

The transformer/power supply that came with my iPad 2 offers the most amperage to charge two cells, compared with the cell phone units we have. Typically I will pull the battery once the meter shows charging 4.2 V. After they rest, the voltage is 4.06 to 4.12 or so, but I am not sure how long the charger has been at 4.2 volts.


CandlePowerForums App


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## HKJ (Dec 19, 2014)

KITROBASKIN said:


> The transformer/power supply that came with my iPad 2 offers the most amperage to charge two cells, compared with the cell phone units we have. Typically I will pull the battery once the meter shows charging 4.2 V. After they rest, the voltage is 4.06 to 4.12 or so, but I am not sure how long the charger has been at 4.2 volts.



LiIon batteries are never fully charged when voltage read 4.2 volt, it has only reached the CV phase and it also needs some time before the battery is full (Usual ½-1 hour, but depends on a lot of factors).


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## Albinoni1967 (Dec 20, 2014)

is it possible to use a 2amp USB wall socket charger with this device. Lets say for eg the charger that came with my Samsung Galaxy Note II has a 2amp charger and can I use it on this, or does it have to be a 1amp charger.


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## StandardBattery (Dec 20, 2014)

It would be fine, maybe even better.


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## Albinoni1967 (Dec 20, 2014)

StandardBattery said:


> It would be fine, maybe even better.



Ok thanks for that, just is on the back where the charge plug goes into it says 1 amp and I thought a 2amp one would ruin the charger.


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## StandardBattery (Dec 20, 2014)

Albinoni1967 said:


> Ok thanks for that, just is on the back where the charge plug goes into it says 1 amp and I thought a 2amp one would ruin the charger.


That's a maximum rating not to be exceeded. The electronic device controls the amount of power it uses. The biggest issues with USB adapters is the variety of methods used to indicate to the device what the maximum power that is available. So the worst thing that would happen is the charger would think it had only 500mAh available and adjust it's charging accordingly. This is not very likely for a 1A requirement, or with this adapter or charger, *but you don't have to worry about damaging either device.*


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## Albinoni1967 (Dec 21, 2014)

Also another question here re this charger, I noticed with the digital display the top display shows the amps the battery is being charged at, but can this be controlled or set manually or is it Auto. Lets say for eg on my XTAR VP1 on the front panel there is a button that I press to say what I want to charge the battery at, but does the VC2 have this as well or is it Auto and decides for itself


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## HKJ (Dec 21, 2014)

Albinoni1967 said:


> Also another question here re this charger, I noticed with the digital display the top display shows the amps the battery is being charged at, but can this be controlled or set manually or is it Auto. Lets say for eg on my XTAR VP1 on the front panel there is a button that I press to say what I want to charge the battery at, but does the VC2 have this as well or is it Auto and decides for itself



The display does not show the charge current, but the maximum possible charge current.
It cannot be adjusted, but depends on the USB power supply used, i.e. not on the batteries being charged.


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## KITROBASKIN (Dec 22, 2014)

The 350 mAh 10440 Efest batteries I use in my MBI HF do just fine, if a little slow, being charged from the CottonPickers charger at a nominal 100 mA but now when I want to charge it faster I can use the Xtar VC2 with an 18650 in one bay and the lower powered USB cell phone power supply that only charges each battery at about 350 mA. I believe that keeps the charging at about 1C for the small 10440. When it is charged, I pull it from the VC2, and the 18650 starts charging at ~500mA at that point.



Albinoni1967 said:


> Also another question here re this charger, I noticed with the digital display the top display shows the amps the battery is being charged at, but can this be controlled or set manually or is it Auto. Lets say for eg on my XTAR VP1 on the front panel there is a button that I press to say what I want to charge the battery at, but does the VC2 have this as well or is it Auto and decides for itself


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## HistoryChannel (Dec 23, 2014)

Great review! I just ordered 2 of these for portability. I have the VP1 for home charging but this VC2 will be great to use with a portable battery pack like the Anker 2nd Gen Astro2 9600mAh 2-Port 3A Portable Charger. And also with my 20w portable solar panel. I'll have a way to charge my 18650 batteries when I'm hiking now!

Thanks HKJ for your incredible reviews as always!


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## curlysir (Dec 23, 2014)

Just received one of these today and for a small USB powered charger is very good. The charger worked as I expected and described in this review and fully charged and showed full as expected. This charger has worked much better then the Nitecore UM20 I have which will charge the battery fully but would not show that is was complete, the bars were still going up and down on it and it showed 97%, but an inline amperemeter showed the charge was complete.

The Xtar VC2 will be my travel charger.


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## candle lamp (Dec 24, 2014)

Thanks a lot for your excellent test review. HKJ! :thumbsup:


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## kreisl (Jan 9, 2015)

looks like simulated CC/CV profile. or, does not look good.

*if* i  measured the following graph on my charger, then that looks like genuine CC/CV profile?


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## HKJ (Jan 10, 2015)

kreisl said:


> looks like simulated CC/CV profile. or, does not look good.



It looks fine and you cannot say if it is simulated or not from that curve.




kreisl said:


> *if* i  measured the following graph on my charger, then that looks like genuine CC/CV profile?



This curve has a very sharp transition from CC to CV, but the chart is misleading, because it is not measured at the battery. It will be a bit more rounded when measured directly at the battery.


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## Flashy808 (Jul 15, 2015)

Nice Review but could you test it with NiMHs too?

What would you prefer out of the 2: The Nitecore D4 or the Xtar VC4 (kind of need help deciding -need a good 18650 & NiMH charger).
The D4 you can actually select what type of batteries are charging and what mode you want or something like that but whereas the VC4 it does it all automatically (and correctly)?? Right?

Also what USB adapter are you using (I saw the list but I'm just curious)?

Thanks :thumbsup:


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## HKJ (Jul 15, 2015)

Flashy808 said:


> Nice Review.
> 
> What would you prefer out of the 2: The Nitecore D4 or the Xtar VC4 (kind of need help deciding -need a good 18650 & NiMH charger).
> The D4 you can actually select what type of batteries are charging and what mode you want or something like that but whereas the VC4 it does it all automatically (and correctly)?? Right?



I generally prefer the VC4, but the current is too high for 10440 cells. On both chargers you must select current, on VC4 by using the right slot, on D4 by holding the button down.
The technical display on D4 does not show more useful info than VC4, it shows less.


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## Flashy808 (Jul 15, 2015)

HKJ said:


> I generally prefer the VC4, but the current is too high for 10440 cells. On both chargers you must select current, on VC4 by using the right slot, on D4 by holding the button down.
> The technical display on D4 does not show more useful info than VC4, it shows less.



Oh ok thanks I kind of understand now.

OK I just realised something silly...
The VC2 can't charge NiMH BUT the VC4 CAN now that's just kind of silly... :thumbsdow
But I'm sure there is a good reason like cost and size of hardware needed right??

& What about the USB Adapter?

THANKS


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## Flashy808 (Jul 16, 2015)

Flashy808 said:


> Oh ok thanks I kind of understand now.
> 
> OK I just realised something silly...
> The VC2 can't charge NiMH BUT the VC4 CAN now that's just kind of silly... :thumbsdow
> ...



Also what USB Adapter do you use?

Do you recommend a regular iPad 12W charger?

Also I would like you to review this Adapter on your website and tell me what you think Please: http://www.amazon.com/dp/B005CG2ATQ/?tag=cpf0b6-20 

Of course this is all for the VC4 charger.

Thanks for helping a Noob :thumbsup:


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## HKJ (Jul 16, 2015)

Flashy808 said:


> Also I would like you to review this Adapter on your website and tell me what you think Please: http://www.amazon.com/dp/B005CG2ATQ/?tag=cpf0b6-20



At the current time I usb chargers in queue for a couple of months and will not add more chargers to it, before I have reduced the queue significantly.


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## Flashy808 (Jul 16, 2015)

HKJ said:


> At the current time I usb chargers in queue for a couple of months and will not add more chargers to it, before I have reduced the queue significantly.



Oh I see.
Guess that's what it is like being a charger & adapter tester...
Thanks Anyway!


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## HKJ (Jul 16, 2015)

Flashy808 said:


> Oh I see.
> Guess that's what it is like being a charger & adapter tester...



With the speed I publish reviews I need some queue or I could keep up, but sometimes I get a big box of devices to review from some dealer/manufacturer and the queue gets rather long.
At the current time I am filled up with batteries and usb chargers, last year it was battery chargers and batteries.


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## HaileStorm (Jul 24, 2015)

Hi hkj,

Which charger is better, the VC2 or the Nitecore UM10? I will be charging mostly 18650s, 16340s and a 14500 IMR. I also have a few eneloops and it would be a bonus if this charged those as well. Also, can I use the charger that of my old ipad for this?


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## HKJ (Jul 24, 2015)

HaileStorm said:


> Hi hkj,
> 
> Which charger is better, the VC2 or the Nitecore UM10? I will be charging mostly 18650s, 16340s and a 14500 IMR. I also have a few eneloops and it would be a bonus if this charged those as well. Also, can I use the charger that of my old ipad for this?



I do prefer the VC2, it is dual channel and has a useful display. The UM10 has one advantage: It is considerable faster to charge 18650 cells.
I have seen some rumors that VC2 will get an upgrade later this year to include NiMH, I do not know if it is true.

I expect the iPad charger will be fine.


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## HaileStorm (Jul 24, 2015)

Okay, great thank you hkj. How much faster does the um10 charge compared to the vc2?


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## HKJ (Jul 24, 2015)

HaileStorm said:


> Okay, great thank you hkj. How much faster does the um10 charge compared to the vc2?



Around 2/3 the time of VC2, but it will depend on the batteries, with old batteries the difference will be smaller.


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## HaileStorm (Jul 24, 2015)

Oh all right, not that big a difference when you factor in a second charging bay. I guess I'll be changing my order to the vc2 then. Thanks so much, hkj!


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## rickwhoo (Jul 28, 2015)

So will a 5v 2.1a adapter be best for this charger? I just ordered this charger and saw that I need an adapter.


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## sandalian (Nov 16, 2015)

Been using this charger for two weeks and sometimes confused with the mAh label shown on the digital display.
My battery is 400 mAh but sometimes it says 0xx mAh and already full.

Does it describe the current capacity of the battery, or else?


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## HKJ (Nov 16, 2015)

sandalian said:


> Been using this charger for two weeks and sometimes confused with the mAh label shown on the digital display.
> My battery is 400 mAh but sometimes it says 0xx mAh and already full.
> 
> Does it describe the current capacity of the battery, or else?



It shows how much the charger has put into the battery. If you starts with a nearly full battery it will not be very much.


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## sandalian (Nov 17, 2015)

HKJ said:


> It shows how much the charger has put into the battery. If you starts with a nearly full battery it will not be very much.



Ah, noted. Thanks!


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## mzil (Dec 5, 2016)

HKJ said:


> It shows how much the charger has put into the battery. If you starts with a nearly full battery it will not be very much.


I was bummed to learn this, because otherwise this charger seemed like a good deal for my needs.  Thanks for the info though.

What's a good, inexpensive charger like this but that actually performs a test to see the true remaining mAh?


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## HKJ (Dec 5, 2016)

mzil said:


> I was bummed to learn this, because otherwise this charger seemed like a good deal for my needs.  Thanks for the info though.



It has its applications. If you start from an empty battery you will get the total capacity else you will get an idea about how far you drained the battery.




mzil said:


> What's a good, inexpensive charger like this but that actually performs a test to see the true remaining mAh?



LiitoKala Lii-500 and Opus BT-C3100 is the two most common chargers for measuring capacity.


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## StorminMatt (Dec 6, 2016)

HKJ said:


> It has its applications. If you start from an empty battery you will get the total capacity else you will get an idea about how far you drained the battery.



I actually feel like this is quite a useful feature on my VC4. It's a shame they had to do away with it when they upgraded to the Plus Master.


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## mzil (Dec 7, 2016)

HKJ said:


> It has its applications. If you start from an empty battery you will get the total capacity else you will get an idea about how far you drained the battery.
> 
> LiitoKala Lii-500 and Opus BT-C3100 is the two most common chargers for measuring capacity.


Thank you for all your helpful reviews. I read the Opus BT-C100 review and I think the price is better for me even though it is limited to only one battery.
If I forget or fall asleep and leave a battery in it for many hours after it is fully charged do I damage the battery, the charger, or potentially start a fire?


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## HKJ (Dec 7, 2016)

mzil said:


> If I forget or fall asleep and leave a battery in it for many hours after it is fully charged do I damage the battery, the charger, or potentially start a fire?



No, but it is never recommended to leave the batteries in a charger.


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## OldSage (Jul 1, 2017)

*Re: Test/Review of Charger Xtar VC2 AND questions??*

HKJ, thanks for another quality review.
This was the charger ordered (in transit). The slower charging speed is not a real issue most days. Quality of charger is.
Looked at the PlusMaster version, but in no need for another NiMh "smart" charger and USB power source. 
You note for the + version a lower termination current would be better. What is considered an ideal termination current?

Clicked over to your power source review page. Now you have me scared/paranoid about my drawerful of probably junky back up power sources. Time for the trash bin. Do use Anker brand USB power sources. Including the 5-port you reviewed. The older model. Like your friends unit have lost one port.


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## scviper576 (Oct 5, 2017)

I am trying to find out why 1 of my batteries caused a reduction in amps going in? This happened with 2 of my batteries the first time it was .2a and the second it was .3a when I remove that battery the other would charge at .5a. All the batteries being charged are LG HG2


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## ChrisGarrett (Oct 5, 2017)

scviper576 said:


> I am trying to find out why 1 of my batteries caused a reduction in amps going in? This happened with 2 of my batteries the first time it was .2a and the second it was .3a when I remove that battery the other would charge at .5a. All the batteries being charged are LG HG2



Are you using a cheap power supply, or is your power supply going bad?

Chris


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## scviper576 (Oct 5, 2017)

I tried 2 different power supplys to make sure and both do the same. If I pull out the battery that is causing the drop in amps it goes back to .5a the first charger is a Samsung 2.0a and the second is an Asus 2.0a.


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