KD all-in-one charger

[LiteTheWay]

I know we have had at least one thread on this ( http://kaidomain.com/ProductDetails.aspx?ProductID=2717 ) KD 'all-in-one' single channel before but no data I could find. So I thought I would give some too see if others had checked out this potentially useful 'travel' charger.

Open circuit - no battery in place: 9.37v

With an AW protected 14500 3.7v in place: 4.17v

With a MAHA Powerex NiMH 1.2v AAA OR AA in place: 1.35V.

My 'experiments' so far seem to suggest it terminates correctly. I don't have any 9v batteries to test but I assume the high resting charge is so it can charge 9v batteries.

ANY OTHER VIEWS/DATA ON THIS CHARGER?

 

[horizonseeker]

i have one, haven't used it much, only charged my nimh AA's, but the batteries seems to be hotter than from other chargers after finishing.

I plan to use this as a travel charger for when I carry multiple type cells since other than the heat, I notice no problem with the cell after charging.

 

[shining]

Is it a smart charger, i.e. does it cut off charging Li-Ion/NiMH properly? What is the charging current?

 

[wapkil]

Re: KD/DX (sku. 14885) HG-103W9V all-in-one charger

I have finished testing the HG-103W9V charger (DX sku. 14885) for LiIon and NiMH AA batteries. I think that for both chemistries it uses a simple algorithm based on diminishing current and stopping the normal charge when the voltage reaches the predefined threshold (~4.18V for LiIons, ~1.43V form NiMHs). Then it starts to behave strange, I'll show it on the graphs below.

The charger seems to be safe (but see below) for batteries - unlike most other cheap chargers, instead of overcharging, it undercharges them.

The plot for LiIon batteries looks as follows:



It can be seen that in the first charging phase, the HG-103W9V charged my TrustFire LiIon "900mAh" cell for 100 minutes. I've measured that during the charge the current was systematically lowered. After 100 minutes and reaching ~4.18V, the charger kept some form of a trickle charge:



At first, this trickle charge was strong enough to cause some jumps in voltage. Also the LED that I think should be green when charge is finished was blinking strangely - sometimes it was red, sometimes green, sometimes it was blinking so fast that it looked like some kind orange. After some time the LED calmed down and stayed green. The charging current was lowered to the level sufficient only to keep the voltage on the approximately constant level. Nevertheless it was still there, since the voltage started to lower only after the charger was unplugged (after 596 minutes).



The charger behavior for NiMHs looks somehow different:



The charger seems to use the same charging method - it systematically lowers the current and charges until the battery reaches ~1.43V. Then it stops charging, the voltage drops, and the LED becomes green. The charger wakes up when the voltage drops below 1.4V - the LED becomes red and the charging continues until the voltage reaches 1.43. Then the charge is stopped until the voltage drops below 1.4V. This procedure repeats itself. Maybe it stops when the battery is finally charged enough to not go below 1.4V?


I'm not sure exactly how to interpret this behavior. Obviously the charging algorithm is not correct neither for LiIon cells nor for NiMHs. If a battery is removed immediately after the LED becomes green, it is undercharged (e.g. for a NiMH I saw that it lacks around 200mAh compared to the full charge on Maha C-9000). If a battery is left in the charger to continue its strange trickle charge it may eventually be overcharged. Or maybe not - the trickle charge current seems to be really low :shrug: ?

Keep in mind that I tested this charger only for AA LiIon and NiMH batteries, other sizes, and even other brands, may behave differently.

 

[wapkil]

Yesterday I converted the Akoray K-106 that died on me to a direct driven light. I used the measurements that I wanted to make as an opportunity to compare also how the TrustFire "900 mAh" batteries are charged when using Ultrafire WF-139 and this HG-103W9V charger.

The results are practically identical - on the battery taken from any of the chargers the light lasted 2 hours before the voltage dropped below 3.00V. The difference was negligible - less than four and a half minutes (~3.5%), and it was the charge with HG-103W9V that lasted longer.

I'm wondering if the charger using CC/CV method could perform better - the WF-139 pushes my cells over 4.25V and even this doesn't seem to make them higher charged...

I'm starting to like this charger, I think I'll order another one.

The second conclusion is that my "900 mAh" TrustFires when driven at around 250mA in reality give less than 500mAh, but it doesn't surprise me anymore.

 

[wapkil]

I'm starting to like this charger, I think I'll order another one.

I got another one and this one is a bit different. Here's how it charges my AW black label 14500 and a Trustfire 900:



As you can see, my second charger finishes the charge at 4.2V (I measured 4.2018 and 4.1980 for AW and Trustfire respectively).

When I compared both my chargers charging AW batteries that just arrived to me it looked like this:



The components tolerance, I guess...

 

[LiteTheWay]

Thanks for these interesting test results wapkil. I have two of these too and have also been quite impressed with them.

While I don't have either of them with me at the moment, I do seem to recall that the second one I got had a higher charging output than the first which would seem to fit your last graph.

 

[wapkil]

I recently bought a second DMM with PC connection so I though I would go back to this charger to simultaneously log the current and the voltage behavior. Here are the measurement results:



The plot shows a few interesting things. First of all, the charger works in the true CC/CV mode. What was surprising and made me misinterpret it before is that most of the CV phase is performed after the LED turns green. It means that if you remove the battery when the LED turns green, it will be undercharged (by ~20% IIRC).

Another important information is that in the measured charger the current started at ~330mA and dropped fast to 310mA. This charger can be used to charge 300mAh and bigger 10440 batteries, recently discussed in many threads.

What is worrying is that the charger unfortunately has a low trickle charge current after the CV phase is finished. You can see the jumping current at the end of the graph when it approaches 0.

I have performed a little more detailed test measuring the voltage on the 0.1 ohm resistor connected in series with the battery to confirm that the trickle charge current is there. It is - at the end of the charge the HG-103W9V switches to the strange mode where it pulses the battery with current pulses of max 7mA (as measured by my DMM). This mode lasts for hours so I suspect it is permanently there. I don't have a scope to look at it, but the battery feels these pulses. They don't let it go below certain voltage (4.176V in my test) but when the charger is unplugged the voltage starts to go lower.

I don't know how this trickle charge affects the battery. If my measurements are correct, it is really low - less than 7mA and because of pulsing probably more like half that value. I think that with such a low trickle charge you can safely leave the battery in the charger for hours but you shouldn't do it for days.

To conclude, I still think that this charger is much better than most budget charger alternatives out there. It does some strange things but if used correctly it should be ok. If I was using this charger, I would remove my batteries when the LED turns green if I wanted them to be slightly undercharged or leave them in the charger for a few hours (but not much longer) to top them off to the full charge.

The usual problem is that I measured only my charger - you may get a completely different version looking to be the same. The batteries behavior will probably also differ for different capacities so e.g. additional two hours may be slightly too much for 10440s and too little for 18650. As always, if you want to be completely sure you have to measure the charger that you bought in the configuration that you use

 

[bigchelis]

I have this charger and love it. I stops charging my 18650's at 4.1~4.20 and I can even charge my Li-on C cells too.

I wish there were a charger like this for the D li-on cell. I have the KD li-on D cell charger with cradle and it is really bad quality and will not charge the D cells unless I fiddle with the cord.

 

[TooManyGizmos]

Wapkil ,

Due to your testing and review below , I got one of these chargers. (DX sku. 14885) for LiIon and NiMH AA batteries.($5.16)

I charged an UNprotected DLG-ICR 14500 cell.

I was there when the light went green - removed it within 30 seconds.

It read way Hi at 4.27v. on a properly performing DMM.

There must be a wide variation in the quality control on these chargers.

I can't use this charger !

I recently bought a second DMM with PC connection so I though I would go back to this charger to simultaneously log the current and the voltage behavior. Here are the measurement results:



The plot shows a few interesting things. First of all, the charger works in the true CC/CV mode. What was surprising and made me misinterpret it before is that most of the CV phase is performed after the LED turns green. It means that if you remove the battery when the LED turns green, it will be undercharged (by ~20% IIRC).

Another important information is that in the measured charger the current started at ~330mA and dropped fast to 310mA. This charger can be used to charge 300mAh and bigger 10440 batteries, recently discussed in many threads.

What is worrying is that the charger unfortunately has a low trickle charge current after the CV phase is finished. You can see the jumping current at the end of the graph when it approaches 0.

I have performed a little more detailed test measuring the voltage on the 0.1 ohm resistor connected in series with the battery to confirm that the trickle charge current is there. It is - at the end of the charge the HG-103W9V switches to the strange mode where it pulses the battery with current pulses of max 7mA (as measured by my DMM). This mode lasts for hours so I suspect it is permanently there. I don't have a scope to look at it, but the battery feels these pulses. They don't let it go below certain voltage (4.176V in my test) but when the charger is unplugged the voltage starts to go lower.

I don't know how this trickle charge affects the battery. If my measurements are correct, it is really low - less than 7mA and because of pulsing probably more like half that value. I think that with such a low trickle charge you can safely leave the battery in the charger for hours but you shouldn't do it for days.

To conclude, I still think that this charger is much better than most budget charger alternatives out there. It does some strange things but if used correctly it should be ok. If I was using this charger, I would remove my batteries when the LED turns green if I wanted them to be slightly undercharged or leave them in the charger for a few hours (but not much longer) to top them off to the full charge.

The usual problem is that I measured only my charger - you may get a completely different version looking to be the same. The batteries behavior will probably also differ for different capacities so e.g. additional two hours may be slightly too much for 10440s and too little for 18650. As always, if you want to be completely sure you have to measure the charger that you bought in the configuration that you use

 

[45/70]

That is pretty high, TMG. You're the first person I'm aware of, that had one of these that was that far off.

As far as wide variance between chargers, I suppose for $5.16, this is to be expected. Mine works quite well and the measured voltages of smaller LiCo cells is usually 4.17-4.18 Volts when the LED turns green. Haven't done very much with NiMH cells, except to top a few off. The biggest complaint I have, is that it trickle charges, less than most cheapie chargers, but a trickle just the same.

Dave

 

[VidPro]

wapkil
Thanks for providing the data.:thumbsup:

Rest of my post is just noise comparably.
I had heard that the ni-mhy charge on it was voltage based termination, and it looks like a (sort of) float maintain type of alogrythm i have seen before.
People were indicating that it would not fully charge ni-mhy, but looks like it will top them off ?? forever??

wonder what happens when . . . the voltage of the li-ion drops below 4.1 (or thereabouts) if it doesnt kick back in again too?
you dont happen to have a crappy self discharging li-ion on you do you
or a creative (but safe) use of a discharge load while the battery is still on the charger, to find out what happens next.

i suspect that from what was said about it (and the other one) in reviews. That for both chemistries it uses the same alogrythm with differing voltages , based solely on where the voltage of the battery falls when placed on the charger. which is a cool & simple concept.
The thing doesn't really know one from the other, it just works with what it is handed, within the voltage rage the item is at. <--- that is what i ASSUME.

 

[TooManyGizmos]

Here is something else I don't understand .... maybe someone can explain ?

Without batteries installed ...............

My Pila max voltage output is 4.15v

The DX Universal (sku 14885) is 9.15v

On any charger that is expected to charge any cell NO HIGHER than 4.21v ....... why would the output be higher than 4.21v ?

Seems that the output should not exceed 4.21v . If it is ... it can overcharge the cell ..... right ?

WHY is the DX Universal output so Hi ?
.

 

[45/70]

WHY is the DX Universal output so Hi ?

Well TMG, I certainly couldn't explain it, but I'm sure it has to do with the charger being able to charge "9 Volt" NiMH/NiCd batteries. Somehow, and again, I'm sure not the one to explain it, this charger determines what Voltage range the cell that is inserted is, and then "adjusts" to the proper voltage, for NiMH/NiCd, Li-Ion cells, and 9 Volt NiMH/NiCd batteries.

I Know, I'm not much help here, but anyway, I'm pretty sure that's why you get a 9+ Volt reading off the charger.

Dave

 

[TooManyGizmos]

Thanks Dave ,

I'm sure you are right .

I didn't even think about the 9v connectors. (which I don't use)

It should have been obvious ..... but Duhhh :duh2:

 

[ToNIX]

My 14500 just came off the charger at 4.22v. I'll have to check the volt meter %. I think (from memory) that it's 0.8%.

 

[wapkil]

Wapkil ,

Due to your testing and review below , I got one of these chargers. (DX sku. 14885) for LiIon and NiMH AA batteries.($5.16)

I charged an UNprotected DLG-ICR 14500 cell.

I was there when the light went green - removed it within 30 seconds.

It read way Hi at 4.27v. on a properly performing DMM.

There must be a wide variation in the quality control on these chargers.

I can't use this charger !

Yeah, it would be too high also for my liking (at least it is still not dangerous). It's just a $5 item from DX so we cannot even be sure that the one you bought has the same design as the ones I have. The protection shouldn't have any effect here so it seems you were unlucky. My two chargers still work correctly. To be honest, I would be surprised if there was any traditional quality control on these chargers. Maybe except catching the chargers that are completely dead...

I had heard that the ni-mhy charge on it was voltage based termination, and it looks like a (sort of) float maintain type of alogrythm i have seen before.
People were indicating that it would not fully charge ni-mhy, but looks like it will top them off ?? forever??

I don't use this charger with NiMHs but it's quite possible that it tops them off in a fashion similar to how it delicately trickle charges Li-Ions.

wonder what happens when . . . the voltage of the li-ion drops below 4.1 (or thereabouts) if it doesnt kick back in again too?
you dont happen to have a crappy self discharging li-ion on you do you
or a creative (but safe) use of a discharge load while the battery is still on the charger, to find out what happens next.

AFAIR there are many dedicated ICs that restart the charge if the voltage drops below 4.0V or 4.1V. Unfortunately I don't have a Li-Ion cell that would drop below 4.1V soon after charging. I don't have an idea either how to easily simulate this behavior.

i suspect that from what was said about it (and the other one) in reviews. That for both chemistries it uses the same alogrythm with differing voltages , based solely on where the voltage of the battery falls when placed on the charger. which is a cool & simple concept.
The thing doesn't really know one from the other, it just works with what it is handed, within the voltage rage the item is at. <--- that is what i ASSUME.

This is how I suspect that this charger works but I prefer algorithms designed specifically for particular chemistries. On the other hand it is much cheaper to manufacture such a simple charger and it seems to be working rather well. At least if you are lucky enough to get the charger with appropriate cutoff levels.

 

[45/70]

......To be honest, I would be surprised if there was any traditional quality control on these chargers. Maybe except catching the chargers that are completely dead...

You're probably right. I only have one of these chargers, but I have to say that one of the things that impressed me the most, is the quality of the soldering job on the PCB, as compared to most "cheapo" chargers. There exist no cold solder joints on the board. This seems to be a rarity, in my experience. Maybe I too, just got lucky.

Dave

 

[Nil Einne]

So am I right that this thing automatically detects what cell type (probably by the voltage) and chargers appropriately?

Hmm I'm a bit paranoid it may randomly decide to charge my NiMH cells as Li-ion or Li-ion as NiMH but I guess it's difficult to make it so it's that flawed. (Well if you've discharged your Li-ion to ~1.2V maybe, but if you've done so they're pretty much dead anyway.)

BTW someone disambled one DX if you wanna look at the insides.

 

[45/70]

BTW someone disambled one DX if you wanna look at the insides.

That's not the charger we're talking about. This is it. I've heard some not so good things about the TrustFire. For one thing, if it charges at anywhere near the rate it supposedly does, it's way too much current for anything smaller than a 16340. Forget about charging 10440's with that one.

Yes, the HG-103W9V does determine the proper voltage to charge the cells at, so far anyway.

Dave