Review : Xtar VC2 Charger

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old4570
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Review : Xtar VC2 Charger

 

Xtarlight.com was kind enough to send me the VC2 for review .. 

http://www.xtarlight.com/05-chanpin/p-001-1.asp?styleid=324  Product page . 

 

If you have not become familiar with Xtar chargers , then it may be time you did ( Perhaps a bold statement on my part , perhaps not ! )

Xtar has been putting in some serious effort in the field of battery chargers for flashlight enthusiasts , and it would not be wrong to say they are taking a leading role in making chargers more user friendly , safer , and informative to prospective users . Im not going to bore you with every detail , that is what the link to the product page is for . 

The VC2 is a full sized charger capable of handling the 18700 and 26650 batteries , as well the 16340 ( more latter ) . As well the features built into the charger make it well worth a careful look .  Lets start with soft start ( I really like this feature ) .

Most chargers on the market start off at high current when the battery is depleted ( lets say 1Amp ) and as the battery charges the charge current progressively lowers , especially as the charger approaches 4.2v or cut off . Now its nice to have a fast charger , but often these chargers are not that fast at all because the current towards the end is so low , the process can be drawn out by over an hour , making the high current fast charger not really that fast after all . Now I was talking about soft start here .

 When a battery is depleted ( low voltage ) , the lower the depletion the more stress the battery is under ( if you let me call it that ) . Is high current a good idea when the battery is in a state of low voltage ? Perhaps not , and to this end Xtar has built in soft start . The charger charges more gently , giving the battery time to absorb the energy more efficiently . This can only be good for long term battery life .  Also the charger analyses the battery , checking a batteries health and charging accordingly . 

 You might think this bogus !  But I charged all my 16340 and one battery it refused to charge .. Over and over again I tried to force the charger to charge the battery and the charger refused every time ..  In the end i pop'ed the battery into another charger for a quick charge and then put it back in the VC2 which refused to charge it . I gave up and walkied out of the room for a minute ( to get a drink ) and when I came back and picked up the battery , it was in a state of Thermal runaway ! 

 I walked very quickly to the back door and tossed the 16340 out the door ..   I then got a container of water and put the battery in it for a few hours . The battery didn't flame or explode but certainly the potential was there !  And the Xtar VC2 refused to charge that battery , if I had not been stubborn , there would never have been a situation . But now we know dont we , the VC2 can pick up on bad batteries . Because I was the test dummy .

Charging and discharging :  

For three days , I kept charging and discharging a AW16340 that was 5 or more years old ..

I put it in my Turnigy Hobby charger and discharged it @ 500mAh , then I would rest it and charge it in the VC2 .. The charger was extremely consistent , my first discharge returned 500mAh capacity , the second returned 494mAh and after that it climbed slowly to where I got 510mAh capacity from the last discharge ( to 3v @ 500mAh ) . The only time I got a soft start was when I pulled the battery from the discharge and put it straight in the charger ( VC2 ) without any rest ( allowing the voltage to find its resting voltage ) . This meant the battery was still under some stress and the charger made the appropriate change to the charge current .  To date I have not seen the charge current increase ( single cell ) when soft starting , so if the charger starts @ 350mAh then for me it has continued at that rate to completion .  

Soft Start :

I have already mentioned that for me , if the charger soft started it did not increase the charge current but rather maintained it to completion. There are two reasons for the charger to soft start that Im aware off . Voltage state of the battery . If the voltage is low ( much under 3.8v ), the charger may soft start , and the second is battery condition .  The nice thing is that the charger shows you the battery voltage before it begins to charge . And it also shows you the termination voltage , well there about's as the increments ( V ) are a little large , but still very much a ball park figure .  If you are charging a battery and it soft starts , wait till you reach about 3.8v and restart the charger and it should revert to a 500mAh charge rate . 

VC2 :

The VC2 certainly gives the prospective new owner some important information . 

The starting voltage , termination voltage , how much current went into the battery and if the voltage is high enough and the charger soft starts this could be a indication of a bad battery . If its due to very low voltage then perhaps you need to charge batteries earlier . On termination I saw no trickle charge going to the battery , so how you feel about leaving a battery in the charger ? 

 

 

Conclusion : 

I have spent more than 3 days charging batteries to get a feel for this charger . And I have only two negative thing to say about it , it really wants two current meters to match the voltage meters , so you can read each channel independently . This is after all a two channel charger , so why the current gauge is  shared between the two channels ? That's my gripe ..

The 500mAh charge rate for me is acceptable , but for many it may be an issue one of two ways . For larger batteries it may be a little on the slow side ( sitting here watching a 18650 get charged very slowly ) . And for 16340 batteries 500mAh is about the maximum charge current you would want to subject the battery to , I would very much prefer around 250mAh for a 16340 myself to possibly 350mAh rather than 500mAh . But I accept the fact that when you make a charger for such a large range of batteries there needs to be compromise , and 500mAh is about as good a compromise as there is .  

Over all , this is one seriously good product from Xtar . I found nothing to fault in regards to quality or design . It charged the smallest 16340 to my 18700 with no issue , it works and works well .  I have no hesitation in recommending this charger , my sample is brilliant and as I sit in front of my computer typing this I am also monitoring a 18650 as it is charging . Its one thing to watch a charger and have no idea what is going on , now with a glance I have instant real world feedback from the charger . 

http://www.xtarlight.com/05-chanpin/p-001-1.asp?styleid=324     Visit the Xtar product page for the VC2 , and get familiar with its features :

Thank you Xtar , 

 Always remember , the easiest thing in the world to do , is to expel hot air from your lungs and through some vocal chords ..
The resulting sound may , or may not be worth listening too ….

 

Edited by: sb56637 on 06/25/2015 - 14:28
WarHawk-AVG
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Nice…sounds like it has a TP4057 chip in it….

Datasheet

here is a charge pattern (notice the low initial charge current)

here is a really cool dual TP4057 board similar to those small TP4056 boards…nice thing about the TP4057, it’s reverse polarity protected!
http://www.icstation.com/product_info.php?products_id=3202

Nice review…thanks

Bort
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How did it determine your 16340 was defective?

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

HKJ
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WarHawk-AVG wrote:
Nice...sounds like it has a TP4057 chip in it....

I does not. My review: http://budgetlightforum.com/node/35962

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

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I have this charger too and I like the fact that it will display the mAh for checking battery capacity. Also, I plan on using it out on camping trips with one of my portable USB power supplys. And in the car with the USB adapter for on the go charging. From my uses so far it sure seems a great product for the money.

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Thanks for the review, old4570 Big Smile

I got the VC2 charger on a whim about a month ago and am very happy with it.
Certainly one of my better purchases.

Lights out! That's when things get interesting...

old4570
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Bort wrote:
How did it determine your 16340 was defective?

Good question ! 

The charger has short circuit protection , the battery might have had a short ( internally ) and sensing the short may have refused to charge the battery .. 

Often very old batteries degrade to the point where they short internally , and charging them can lead to thermal runaway and Boom / flame / fire ...

We have seen plenty of reports on Boom / Flame / Fire over the years ... So having a charger that wont charge such a badly degraded battery is ?  Good !

 Always remember , the easiest thing in the world to do , is to expel hot air from your lungs and through some vocal chords ..
The resulting sound may , or may not be worth listening too ….

 

Bort
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old4570 wrote:

Bort wrote:
How did it determine your 16340 was defective?

Good question ! 

The charger has short circuit protection , the battery might have had a short ( internally ) and sensing the short may have refused to charge the battery .. 

Often very old batteries degrade to the point where they short internally , and charging them can lead to thermal runaway and Boom / flame / fire …

We have seen plenty of reports on Boom / Flame / Fire over the years … So having a charger that wont charge such a badly degraded battery is ?  Good !


Other chargers don’t do this (or do they just terminate immediately)?

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

hank
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Is that a likely guess, or is there some documentation on what it’s measuring when it refuses to charge?

Any guess whether that bad cell would have started heating up if you’d just put it in your sock drawer instead of putting it into the VC2 that one last time?
(Did the VC2 do anything that might have triggered a thermal runaway, or would it have happened without being in the charger?)

I realize the latter is just a guess. But maybe knowing what the VC2 does during the first few seconds when a cell is put in, before it refuses to charge it, might be a clue.

old4570
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hank wrote:
Is that a likely guess, or is there some documentation on what it's measuring when it refuses to charge? Any guess whether that bad cell would have started heating up if you'd just put it in your sock drawer instead of putting it into the VC2 that one last time? (Did the VC2 do anything that might have triggered a thermal runaway, or would it have happened without being in the charger?) I realize the latter is just a guess. But maybe knowing what the VC2 does during the first few seconds when a cell is put in, before it refuses to charge it, might be a clue.

Im not privy to the inner workings of this charger , this is a question probably best levelled at Xtar ...

My guess is that the first thing the charger does is check for a short circuit and or reverse polarity , since it has reverse polarity protection .

So it wont charge AA batteries to 4.2v , it wont try to charge a backward battery , and it wont charge when detecting a short .  How the charger does this , ask Xtar ..

 Always remember , the easiest thing in the world to do , is to expel hot air from your lungs and through some vocal chords ..
The resulting sound may , or may not be worth listening too ….

 

Bort
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old4570 wrote:

hank wrote:
Is that a likely guess, or is there some documentation on what it’s measuring when it refuses to charge? Any guess whether that bad cell would have started heating up if you’d just put it in your sock drawer instead of putting it into the VC2 that one last time? (Did the VC2 do anything that might have triggered a thermal runaway, or would it have happened without being in the charger?) I realize the latter is just a guess. But maybe knowing what the VC2 does during the first few seconds when a cell is put in, before it refuses to charge it, might be a clue.

Im not privy to the inner workings of this charger , this is a question probably best levelled at Xtar …

My guess is that the first thing the charger does is check for a short circuit and or reverse polarity , since it has reverse polarity protection .

So it wont charge AA batteries to 4.2v , it wont try to charge a backward battery , and it wont charge when detecting a short .  How the charger does this , ask Xtar ..


We can’t just trust it can detect bad batteries, we need to know what it can and not detect, maybe it can detect shorts, or maybe high internal resistance, or something else, or all of the above, we can’t assume much from a sample set of one battery.

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

old4570
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Bort wrote:
old4570 wrote:

Bort wrote:
How did it determine your 16340 was defective?

Good question ! 

The charger has short circuit protection , the battery might have had a short ( internally ) and sensing the short may have refused to charge the battery .. 

Often very old batteries degrade to the point where they short internally , and charging them can lead to thermal runaway and Boom / flame / fire ...

We have seen plenty of reports on Boom / Flame / Fire over the years ... So having a charger that wont charge such a badly degraded battery is ?  Good !

Other chargers don't do this (or do they just terminate immediately)?

 

Depending on the charger , ????

If your comparing to the older dinosaurs , or what I like to think of now as brute force chargers ..  These are chargers , that much like a hammer is designed to drive a nail , are designed to charge batteries and never really stop .

 They essentially trickle charge at very low current when reaching a certain voltage and at this point the charge current is hopefully low enough that the batteries internal resistance brings charging to an end ( a stale mate of sorts where charge current is balanced against internal resistance ) .. Obviously these sorts of chargers are CHEAP as dirt , have there uses , but as well can be as problematic as they can be useful . 

I think most of the boom / flame events have been with this style of charger ...

Essentially they do not detect problems ( they are not designed to ) so don't stop charging when and if a battery goes into thermal runaway , so just keep adding fuel to the fire so to speak .

 

 As for my battery , did I forget to mention I popped it in another charger for a moment to see if it would charge ? ( Let me read back )

Nope sure did , .........

 Always remember , the easiest thing in the world to do , is to expel hot air from your lungs and through some vocal chords ..
The resulting sound may , or may not be worth listening too ….

 

old4570
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Bort wrote:
old4570 wrote:

hank wrote:
Is that a likely guess, or is there some documentation on what it's measuring when it refuses to charge? Any guess whether that bad cell would have started heating up if you'd just put it in your sock drawer instead of putting it into the VC2 that one last time? (Did the VC2 do anything that might have triggered a thermal runaway, or would it have happened without being in the charger?) I realize the latter is just a guess. But maybe knowing what the VC2 does during the first few seconds when a cell is put in, before it refuses to charge it, might be a clue.

Im not privy to the inner workings of this charger , this is a question probably best levelled at Xtar ...

My guess is that the first thing the charger does is check for a short circuit and or reverse polarity , since it has reverse polarity protection .

So it wont charge AA batteries to 4.2v , it wont try to charge a backward battery , and it wont charge when detecting a short .  How the charger does this , ask Xtar ..

We can't just trust it can detect bad batteries, we need to know what it can and not detect, maybe it can detect shorts, or maybe high internal resistance, or something else, or all of the above, we can't assume much from a sample set of one battery.

 

A/  I'm quoting Xtar ..

B/ I was giving my best guess

C/ Did I ask anyone to trust anything ?  I simply mentioned it refused to charge it .. And after putting the battery in ANOTHER charger for a moment to see if it would charge , I put the battery down left the room to get a drink , came back and the battery was in thermal runaway ...  That's what happen !

As to why the Xtar refused to charge it , HTF do I know ? I can only give a best guess based on the features of the charger .. Want more , talk to Xtar  .

All I know is what happened , Bad battery , VC2 refuses time and time again to charge it ..  Used another charger and thermal runaway ..

Holly crap , the VC2 just became my no 1 charger .. 

And take the time to read the Xtar literature about what they say the charger can do ...

 Always remember , the easiest thing in the world to do , is to expel hot air from your lungs and through some vocal chords ..
The resulting sound may , or may not be worth listening too ….

 

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HKJ wrote:

WarHawk-AVG wrote:
Nice…sounds like it has a TP4057 chip in it….

I does not. My review: http://budgetlightforum.com/node/35962


Nice…missed that one

Any idea what CC/CV charging chip is on the charger?

HKJ
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WarHawk-AVG wrote:
Any idea what CC/CV charging chip is on the charger?

Probably none, my guess would be that it contains a (probably two) switching regulator that is controlled from a microprocessor.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

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Well I have been giving this some thought !

Battery was a very old Trustfire 16340 with protection circuit , one of the very first Li-ion batteries I have ever purchased ( One of a pair - its sister still lives )

Over the last few years , I have noticed a growing issue with protection circuits , especially in self discharging batteries .

I had a 18650 that would discharge fully in about two months . Now was it a bad battery ? , I didn't think so as I had never noticed such discharge in non protected batteries .

Anyways , I unwrapped the battery removing the protection circuit , re wrapped the battery .. and fully charged it !  A year latter it was still above 4.10 Volts .

 

Back to the issue at hand :

Is the charger sensitive enough to pick up on an internal short in a Li-ion .. ?

Or is it far more likely , the charger picked up on a faulty protection circuit ? and refused to charge the battery !

And putting the battery into another charger to force a charge into it , was enough to short circuit the battery internally creating a thermal event , which was possibly triggered by the protection circuit ? Now this brings up an interesting thought !

Which is more Dangerous , the battery or the protection circuit .. 

For quite some time now , I haven't really been a fan of the protection circuit ( those self discharging batteries and a few other things ) ..

So , how safe is a protected Battery ?

And all the recent flame events , protected or unprotected ?

 Always remember , the easiest thing in the world to do , is to expel hot air from your lungs and through some vocal chords ..
The resulting sound may , or may not be worth listening too ….

 

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Hi Guys,
Today i bought the Xtar VC2 from a vendor on Ebay. I charged a couple an Efest batterys, no problems. According to the instruction manual once the battery is fully charged the display should flash on and off every 10 seconds, this unit doesnt, it stays on continually. this caused concern so i tried to verify that i had a genuine unit. The silver scratch off panel on the label which hides the unique number didnt scratch off it just smudged, further attempts started to rip the label, now im even more concerned. To look at the charger it looks solid, very well built, looks exactly the same as the ones ive seen on youtube even down to the labelling, words all spelt correct, came in a decent box with warranty card. Really does look like the real thing.’‘’‘’ display not flashing indicating charged battery’‘’‘’, ‘’‘‘scratch off label duff’‘’‘’, anyone else have the same issues? thanks in advance.

HKJ
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toad118 wrote:
Today i bought the Xtar VC2 from a vendor on Ebay......

Try writing an email to Xtar explaining the problem and the vendors name.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

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toad118 wrote:
Hi Guys, Today i bought the Xtar VC2 from a vendor on Ebay. I charged a couple an Efest batterys, no problems. According to the instruction manual once the battery is fully charged the display should flash on and off every 10 seconds, this unit doesnt, it stays on continually. this caused concern so i tried to verify that i had a genuine unit. The silver scratch off panel on the label which hides the unique number didnt scratch off it just smudged, further attempts started to rip the label, now im even more concerned. To look at the charger it looks solid, very well built, looks exactly the same as the ones ive seen on youtube even down to the labelling, words all spelt correct, came in a decent box with warranty card. Really does look like the real thing.’‘’‘’ display not flashing indicating charged battery’‘’‘’, ‘’‘‘scratch off label duff’‘’‘’, anyone else have the same issues? thanks in advance.

I hope you have your answer by now from xstar. But with my vc 2 it only flashes when it’s finished 3 times when it’s first done if you miss those three times where the whole.LCD display flashes on and off it won’t flash again it just has over the battery slot going between full and telling you the mah input. I’m surprised no one else has told you that. The scratch off label is really delicate. Almost ripped mine. But it verified. So you most likely for a legit unit.

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