Test/review of Charger Xtar MC4

[HKJ]

Charger Xtar MC4











This is a fairly small 4 slot charger with usb power input from Xtar. It can only charge LiIon batteries.









The cardboard box lists lot of specifications, battery types and features.







The box contains the charger, a usb power supply, a usb cable and a manual.







The charger has a micro usb power connector.







The charger has a red/green led for each slot.

When using only the outer slots the charger will charge with 1A, when charging in any of the center slots the current will drop to 0.5A for all slots.







The slots uses the usual construction and works well. They can handle batteries from 31mm to 71.7 mm long.













The charger can handle two 26xxx battery at a time.

The charger can easily handle 70 mm long batteries, inclusive flat top cells.







Measurements

• Discharges with less than 0.005mA when not connected to power

• Discharges with less than 0.005mA when powered with a full battery

• Will restart if battery voltage drops below 4.10 volt.

• Below 0.5 volt the charger will charge with about 5mA

• Below 2.8 volt the charger will charge with about 50mA

• Above 2.8 volt it will apply regular charge current.

• Charge will restart charging after power loss, but not on battery insertion.

• Power consumption when idle is 0.26 watt for adapter and charger (The charger uses 28mA).

• When center slota are full, outer slots will automatic increase to 1A

This is a nice CC/CV charge curge with a termination current around 120mA.




The two center slots charges with 0.5A, again with a nice CC/CV charge curve, the termination current is lower here (60mA), this is an advantage for smaller cells.



This slot is a 1A slot.




No surprice with these cell, it is nice CC/CV charges.



Even with this old cell.




The two small cells is charged fine, the lower termination current on the 0.5A slot is a good thing here.



With four cells in the charger all slots will charge at 0.5A. This curve is from the first slot and as can be seen it will adjust not only the charge current, but also the termination current (nice).



Using my own power supply I can see the charger uses about 2A from the usb charger.



Adding a 0.5ohm resistor to simulate a long cable or weak charger is very problematic for this charger.
It will charge, but it over charges the batteries. This is not good.



M1: 35,6°C, M2: 38,1°C, M3: 38,1°C, M4: 35,6°C, HS1: 48,6°C




M1: 35,9°C, M2: 38,4°C, M3: 37,9°C, M4: 35,9°C, M5: 38,1°C, M6: 43,4°C, HS1: 54,0°C



The charger is very fast to initialize, it takes about 0.5 second.



When putting a battery in the center slots the charger will reduce the current on all slots to 0.5A.



USB power supply



I decided to do a test of the supplied usb power supply.

• Idle power is 0.06 watt for adapter.

• Output is coded as Apple 2.1A

The supplied usb power can easily deviler the required 2A and maintain 5V output.



Also when used on 120VAC mains.



No problems running one hour at 2A.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.



M1: 53,9°C, M2: 49,9°C, HS1: 57,5°C



M1: 43,5°C,HS1: 49,7°C



M1: 56,6°C, HS1: 60,0°C



HS1: 54,8°C



M1: 54,7°C, HS1: 58,2°C


Testing with 2830 volt and 4242 volt between mains and low volt side, did not show any safety problems.



Conclusion

The charger do a very fine charge curve both for large and smaller LiIon batteries.
BUT there is one serious caveat: It need a good power supply. If it has a week power supply or a long thin cable it may overcharge the batteries!



Notes

The charger was supplied by a Xtar for review.

Xtar is aware of the issue and will fix it. For these first MC4 Xtar recommends using the supplied charger and cable.

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

[zelee]

nice review HKJ :+1:
my VC4 did overcharge my old Li Ion battery once, i use blitzwolf 5 slot charger as it power supply.
too bad this charger can only accept Li Ion battery

[Speed4goal]

Thanks for the review I’ve had the vc2 overcharge older protected batteries until the protection kicked in

[HKJ]

@gauss163

That’s not a “very fine charge curve”.

I did not call that a “very fine charge curve”

@gauss163

But it’s a very fine way to burn your house down with the latest model XTraFire.

It appears to have overcharged to somewhere in the range 4.30-40V (why does the graph not show that region?).

This is one of the worst safety problems that any charger can have, since it could easily cause Li-ion cells to vent with flame.

Charging to 4.3V will not burn your house down. I wonder why you believe it may hit 40V.

@gauss163

I strongly recommend against buying this XTAR (or any) charger that may greatly overcharge Li-ion batteries.

Your usual campaign against Xtar.

[Mr.Scott]

@HKJ

@gauss163

It appears to have overcharged to somewhere in the range 4.30-40V (why does the graph not show that region?).

Charging to 4.3V will not burn your house down. I wonder why you believe it may hit 40V.

I assumed he meant 4.30- . 40V, short hand for 4.30-4.40V. But the missing “.” did catch me on the first read.

[firedome]

Thanks for the review! :+1:

[HKJ]

@gauss163

Those were your words. The review did a very poor job of warning users just how dangerous this XTAR charger can be. Hence my reply.

They where only part of my words.

@gauss163

Of course “4.30-40” means 4.30 to 4.40. But who knows, with your truncated graph, maybe it did reach 40V! Repeated overcharging to 4.30V and above (as shown) can most certainly cause some cells to vent, possibly with flame. And that can certainly burn your house down.

Manufacturers usual test with considerable higher voltage and flame is not allowed

@gauss163

There is most certainly no “campaign against XTAR”. Rather, there is only sage advice from some (absolutely neutral) professionals to avoid dangerous chargers, no matter the brand or marketing hype. Caveat emptor.

You often post warnings against Xtar charger, but not against other chargers that are much more dangerous.
I suppose the reason you are posting in my reviews here is because you got banned on cpf, because you where thrashing one of my reviews there:

Test/review of Conrad energy LiIon 9V 500mAh (Blue)

[chops728]

gauss163 always seems to express how much smarter he is than all of us—I’ve never seen him take the time to review —- only jump to criticize
I thought I was the only one who was not smart enough around here—-Looks like there’s a bunch of us—I have an idea— why don’t we start a forum of our own—maybe something like BLF—— LOL

[teacher]

@chops728

gauss163 always seems to express how much smarter he is than all of us—I’ve never seen him take the time to review —- only jump to criticize

Hmmmm, you have a good point there chops. :+1:

@chops728

I thought I was the only one who was not smart enough around here—-

Well, since you brought it up ole’ buddy…….

@chops728

Looks like there’s a bunch of us—

Yeah…. your right. And I ’be’ one of them. :person_facepalming:

@chops728

I have an idea— why don’t we start a forum of our own—maybe something like BLF—— LOL

Excellent idea!!!
.
.
As always, thank you HKJ for your time & review!! :+1:

[everydaysurvivalgear]

I will not condone the behavior but some people on here frequently charge there lithium cells to 4.40+v per cycle. After many charge cycles the only issue they have had are cells losing capacity quicker and of course then you lose cycle amounts.

We are talking brand name high drain cells. Once again i will not condone what they are doing.

[HKJ]

@gauss163

@HKJ

Manufacturers usual test with considerable higher voltage and flame is not allowed

It is not clear what your point is. Are you seriously claiming that it is ok for consumer Li-ion chargers to highly overcharge cells simply because of the above? Given that you have (religiously!) followed datasheet values in prior arguments, this seems to be a rather dramatic turn of events!

Point is that batteries do not explode or vent flame when slightly overcharged.
This charger do not overcharge during normal operating conditions, if it had done that the conclusion would have been very different.

@gauss163

If you consider the above comments to be “thrashing your review” then we obviously have very different ideas of the importance of safety matters in charger reviews.

When you pick random stuff from my review and then complain about it, it is trashing.
You could have posted the curve and my comment about a caveat (Instead of my comment about the normal charge curves) and then added your opinion.

[chops728]

@gauss163

@chops728

gauss163 always seems to express how much smarter he is than all of us—I’ve never seen him take the time to review […]

I’m afraid you greatly misunderstand my motivation. I joined this forum primarily to share my expertise after working in the industry for many years. After seeing many hobbyists suffer injuries that could have been prevented by proper education, I felt it was my duty to volunteer and help to correct much of the misinformation that permeates the web.

In particular, my motivation has nothing at all to do with “expressing how much smarter…”. Rather, it has to do with sharing knowledge in the hope that it will help others to optimise their use of Li-ion technology in as safe a manner as possible.

OK—I’ll give you the benefit of the doubt—But on more than one occasion I’ve seen you correct me and others— When it comes to me,I’m not a pro by any means— I’m not the smartest or the dumbest—I figure things out like many of us on this forum—- maybe if you tried a friendlier novice approach to adding input we wouldn’t take it to heart so much—- I can see your point to—- I’ve had a hammer and saw in my hand since I was 9—-I watch people in person and on TV that freak me out to their work habits—sometimes I can see the horrors others can’t

[teacher]

…… What about the cornflakes??

[chops728]

@teacher

…… What about the cornflakes??

From the looks of it We’ll have to finish the Cornflakes and graduate to the Wheaties
My Mom use to say “Expect people to be the way they are—Then you won’t be disappointed”

[HKJ]

@gauss163

@HKJ

Point is that batteries do not explode or vent flame when slightly overcharged.

Repeatedly overcharging a Li-ion cell by 0.1V or more is most certainly not a “slight overcharge”, and can most surely lead to venting with flame.

Please post you test of this.
Batteries are tested with considerable higher voltage, without any flames, if you have worked with batteries you ought to know that.

@gauss163

@HKJ

When you pick random stuff from my review and then complain about it, it is trashing.

Serious safety issues are not “random”.

Again pick random stuff to answer, in the next sentence I explained what I mean by random stuff, but as usual you ignore the real point.

[HKJ]

@gauss163

@HKJ

Batteries are tested with considerable higher voltage, without any flames, if you have worked with batteries you ought to know that.

It seems you are attempting to misapply single/few event tests to incorrectly make inferences about future events. Simply because a cell did not vent with flame when overcharged a single/few times does not imply that it will behave likewise after many more cycles of being overcharged. One has to account for cumulative damage, which cannot be done by such simple tests.

As expected you did not post any test.

[everydaysurvivalgear]

I think we all agree that lithiums should not be overcharged at all. 0.1v is on the high side i guess most manufacturers rate cells to say 4.20 volts with a variance of a certain percentage? Say 0.05 volts +/-? Its not really on the extreme side at 0.1v.

This is why it is important for people to check there lithium cells with a multimeter.

I just had a skim through this i am not sure how equivalent it is to modern lithium cells. Plus they dont state end charge current. Actually i think they double the charge capacity.
https://www.researchgate.net/publication/239352605_A_study_of_the_overcharge_reaction_of_lithium-ion_batteries

i will start reading this lol
https://www.researchgate.net/publication/282562588_Overcharge_failure_investigation_of_lithium-ion_batteries

Sorry for the spam HKJ!

[teacher]

@chops728

@teacher

…… What about the cornflakes??

From the looks of it We’ll have to finish the Cornflakes and graduate to the Wheaties
My Mom use to say “Expect people to be the way they are—Then you won’t be disappointed”

Amen brother!!! With Cheerios waiting in the wing………
Where is wd when we need him?

Oh yeah…. your Mom was a smart woman. :+1:
I have not been “disappointed”…… but I am somewhat amazed. :sunglasses:

[teacher]

@gauss163

@HKJ

Batteries are tested with considerable higher voltage, without any flames, if you have worked with batteries you ought to know that.

It seems you are somehow attempting to misapply single/few event tests to incorrectly make inferences about future events. Simply because a cell did not vent with flame when overcharged a single/few times does not imply that it will behave likewise after many more cycles of being overcharged. One has to account for cumulative damage, which cannot be achieved by such simple tests.

@ gauss163 …… Are you saying you are absolutely sure Battery Manufacturers just run what you call a “simple”overcharge test only a single or few times.

Could it not be possible they run it many, many, many times, so as to replicate the “cumulative damage” you refer to?

[HKJ]

@gauss163

@HKJ

As expected you did not post any test.

I don’t need to do my own tests to confirm what is well-known in the industry about the dangers of overcharging Li-ion cells.

Then post a test from somebody else.

@gauss163

Your error is analogous to the same error you made in the past with datasheets and fast-charging algorithms. You are attempting to (mis)apply information in much broader contexts than it applies. You can’t obtain cumulative overcharge damage information from a single overcharge test anymore than you can apply datasheet values on CC/CV algorithms to very different (fast/multistage) charge algorithms (e.g. Philips, Tesla and, more recently, partly in some cellphone fast-charging algorithms).

I believe my biggest error is bothering answering you.