Sysmax/Nitecore/Jetbeam i4 Intellicharger Review (V2): current/voltage comparisons

[HKJ]

Cool review. What happens with all 4 slots charging the same or different batteries? Is that all 4 charging at 750 mAh? That would likely fry the RCR123s I use protected or unprotected. The WF138 or WF139 charger is pretty safe and the only reason I';d buy this is to charge 4 at a time, but not at the expense of cooking the batteries.

Was there any tests done to monitor battery temperature with your review? This is usually a major concern and factor in choosing a new charger.

How effective is this charger at reviving older battteries that will not take a charge on other smart chargers. I'd like to kickstart a bunch of over terminated RCR123s that I can only sometimes fool into charging on my WF138/9 charger.

When using two slots, with a shared charge circuit, the battery will only be charged half the time, but with the full current. I.e. the charge time is nearly double up. 750mA is not a problem for RCR123/16340 batteries, it is a 1C charge and they can handle that.
The charger does not have anything preventing it from charging a low battery, this is not really possible when it also has to charge NiMH.

 

[Beacon of Light]

Thanks but this didn't answer whether it charges at 375mAh or 750mAh using all 4 slots. I would assume 375mAh as how would the charger differentiate the 1&3 slot being used in conjunction with the other paired slot and when used alone 1&3 or 2&4 it halves the charge current.

You say it can a RCR123 handle a 750mAh charge? Maybe, but I sure wouldn't want to charge at that high a setting. For example, a AA NiMH can handle 2000 mAh but is it wise to do? No, it isn't. It fries the cell into premature death.

 

[HKJ]

Thanks but this didn't answer whether it charges at 375mAh or 750mAh using all 4 slots. I would assume 375mAh as how would the charger differentiate the 1&3 slot being used in conjunction with the other paired slot and when used alone 1&3 or 2&4 it halves the charge current.

I believe I did answer that, but obvious not in a clear enough way.

When charging 4 batteries the charge current is 750 mA in about 45% of the time, giving an average charge current of 340 mA for each battery.

 

[Beacon of Light]

That response is even less clear. So it does charge at 750mAh. Too high for RCR123 3.0 volts imo. The 45% of the time makes no sense even when using the idea of alternating currrent 750mAh and then 1 second of 0 mAh. This Pulse width modulation style of charging I would assume is not a very good algorythm for charging. Abrupt surge of current then turn off, then surge again and then turn off. I prefer slow and steady to this. Here's hoping there will be a Maha Wizard one in a style that accepts different cells like this someday.

\

I believe I did answer that, but obvious not in a clear enough way.

When charging 4 batteries the charge current is 750 mA in about 45% of the time, giving an average charge current of 340 mA for each battery.

 

[HKJ]

That response is even less clear. So it does charge at 750mAh. Too high for RCR123 3.0 volts imo. The 45% of the time makes no sense even when using the idea of alternating currrent 750mAh and then 1 second of 0 mAh. This Pulse width modulation style of charging I would assume is not a very good algorythm for charging. Abrupt surge of current then turn off, then surge again and then turn off. I prefer slow and steady to this. Here's hoping there will be a Maha Wizard one in a style that accepts different cells like this someday.\

It can not charge RCR123 3 volt, only 3.6/3.7 volt batteries. The pulsing is not a problem for the batteries, MAHA does exactly the same.

 

[Beacon of Light]

If it will charge 1.2volt AAA/AAs and 3.6/3.7volt RCR123s then why would it have a problem with 3.0volt RCR123s? How would it even determine the RCR123 is 3.0volt versus a 3.6/3.7 volt RCR123? Seems odd as this is advertised as a one charger for all cells/chemistries. This may be a smart charger but I doubt it is THAT smart...

Also will this charge individual solder tab 18650 cells from a laptop battery?

Are you sure the Maha pulses it's charge? I've never been aware of this and I own 2 of these Maha Wizard Ones. Seems you would see the display indicating 0 mAh at times when seeing the charging indicator LED display and I watch it like a hawk when charging cells on the Wizard One.

It can not charge RCR123 3 volt, only 3.6/3.7 volt batteries. The pulsing is not a problem for the batteries, MAHA does exactly the same.

 

[selfbuilt]

Cool review. What happens with all 4 slots charging the same or different batteries? Is that all 4 charging at 750 mAh? That would likely fry the RCR123s I use protected or unprotected.

I see HKJ has already responded to this point (i.e., it alternates the current). I would just add that my testing shows that even in a single channel, RCR doesn't stay at 750mA for long - the average current during charging is less than half of that over the run.

Was there any tests done to monitor battery temperature with your review? This is usually a major concern and factor in choosing a new charger.

The short answer is I don't believe heat is a major issue, as the charger actually charges at a lower current than my Pila or Xtar WP2-2 chargers most of the time. But I don't have comparator heat measurement data for those other chargers, so I wouldn't have a way to put any temp results into context (i.e., I would have to go and re-test those chargers under exactly the same conditions, with the probe in exactly the same spot, etc.).

Plus the reason I didn't do any of this in the first place is that I don't have aother datalogging DMM available for concurrent runs (i.e., I already have to repeat every run twice to get voltage and current readings separately, and would need to everything a third time for temp).

How effective is this charger at reviving older battteries that will not take a charge on other smart chargers. I'd like to kickstart a bunch of over terminated RCR123s that I can only sometimes fool into charging on my WF138/9 charger.

As HKJ said, this charger should charge everything, even over-discharged cells. But I'd recommend tossing cells in that state - it's not really safe to continue to try and charge them.

If it will charge 1.2volt AAA/AAs and 3.6/3.7volt RCR123s then why would it have a problem with 3.0volt RCR123s? How would it even determine the RCR123 is 3.0volt versus a 3.6/3.7 volt RCR123? Seems odd as this is advertised as a one charger for all cells/chemistries.

I have no information on its ability to charge 3.0V cells, but I wouldn't want to try it. Just a guess, but I would be concerned that it would interpret these as overly-depleted 3.7V cells, and then try to way over-charge them. :shrug: Since it is differenting between Li-ion and NiMH on the basis of voltage, I don't see how you could do 3V cells without some additional info. But I will leave that question up to the charging circuitry experts to answer ... :wave:

 

[HKJ]

If it will charge 1.2volt AAA/AAs and 3.6/3.7volt RCR123s then why would it have a problem with 3.0volt RCR123s? How would it even determine the RCR123 is 3.0volt versus a 3.6/3.7 volt RCR123? Seems odd as this is advertised as a one charger for all cells/chemistries.

The charger need to recognize the battery type and then select the correct algorithm. This is fairly easy with only 3.7 volt LiIon and NiMH. I would be just about impossible to include the 3 (or 3.2) volt chemistry in this.

Also will this charge individual solder tab 18650 cells from a laptop battery?

As long as you can get them into the charger. The batteries used in laptops is usual 3.6/3.7 volt LiIon, i.e. the charger supports them.

 

[Beacon of Light]

As HKJ said, this charger should charge everything, even over-discharged cells. But I'd recommend tossing cells in that state - it's not really safe to continue to try and charge them.

Why wouldn't it be safe? It should terminate just like it would as normal. Would the cell being over discharged cause the runaway charge like was notorious on the Lacrosse BC900 chargers where it was charging at over 2000mAh resulting in a complete meltdown including charger and cells?

 

[45/70]

......The pulsing is not a problem for the batteries, MAHA does exactly the same.

Is this your opinion, or......? As we all know, NiMH cells and Li-Ion cells utilize a totally different charging algorithm. Not too long ago, I remember seeing a reference to where Panasonic had some sort of guideline for pulse charging Li-Ion cells. I meant to check for it, but never did. Also, I'm not sure whether this applied specifically to the newer LiNiCo cells, or all types of Li-Ion cells. If you could post a link to where an actual Li-Ion cell manufacturer discusses pulse charging Li-Ion cells, it would be much appreciated.

As for Sysmax/JetBeam/Nitecore calling this a CC/CV charger, I still have a major problem with that. It seems deceiving, to me. From selfbuilt's and HKJ's (first version) own charge graphs, it obviously is not a CC/CV charger, as neither current nor voltage is constant. Similar to the way driver's limit current in our lights, you either have PWM, or current regulation, you can't have both. In the case of the i4 IntelliCharger, it obviously utilizes both pulsed voltage and current and is not CC/CV. That's not to say it isn't a good simulation of a CC/CV algorithm, but......

It could very well be that the way this charger replicates a CC/CV algorithm, that it is acceptable. I'm just not convinced, until I see what the actual Li-Ion cell manufacturers have to say about pulse charging cells.

As for charging smaller cells with this charger, yes, it apparently charges at ~750mA, 45% of the time, as HKJ said. In my opinion, that is not the same as a ~340mA constant current. Not exactly related and perhaps a poor example but, you can drive a 1000mA rated LED at 2000mA with 50% PWM, which is effectively 1000mA. However, regardless of the color bin, it'll have a bluish tint and it won't last very long......

@ selfbuilt, thanks for the review. Fine job.:thumbsup:

Dave

 

[HKJ]

Why wouldn't it be safe? It should terminate just like it would as normal. Would the cell being over discharged cause the runaway charge like was notorious on the Lacrosse BC900 chargers where it was charging at over 2000mAh resulting in a complete meltdown including charger and cells?

LiIon has a safety problem when discharged to much, that is the reason many people warns against reusing over discharged LiIon batteries.

Is this your opinion, or......? As we all know, NiMH cells and Li-Ion cells utilize a totally different charging algorithm. Not too long ago, I remember seeing a reference to where Panasonic had some sort of guideline for pulse charging Li-Ion cells. I meant to check for it, but never did. Also, I'm not sure whether this applied specifically to the newer LiNiCo cells, or all types of Li-Ion cells. If you could post a link to where an actual Li-Ion cell manufacturer discusses pulse charging Li-Ion cells, it would be much appreciated.

As for Sysmax/JetBeam/Nitecore calling this a CC/CV charger, I still have a major problem with that. It seems deceiving, to me. From selfbuilt's and HKJ's (first version) own charge graphs, it obviously is not a CC/CV charger, as neither current nor voltage is constant. Similar to the way driver's limit current in our lights, you either have PWM, or current regulation, you can't have both. In the case of the i4 IntelliCharger, it obviously utilizes both pulsed voltage and current and is not CC/CV. That's not to say it isn't a good simulation of a CC/CV algorithm, but......

It could very well be that the way this charger replicates a CC/CV algorithm, that it is acceptable. I'm just not convinced, until I see what the actual Li-Ion cell manufacturers have to say about pulse charging cells.

As for charging smaller cells with this charger, yes, it apparently charges at ~750mA, 45% of the time, as HKJ said. In my opinion, that is not the same as a ~340mA constant current. Not exactly related and perhaps a poor example but, you can drive a 1000mA rated LED at 2000mA with 50% PWM, which is effectively 1000mA. However, regardless of the color bin, it'll have a bluish tint and it won't last very long......

The 750mA charge current is not to high for the battery and the voltage also stays below the safe limit. The Panasonic specifications I have seen say to stay below 4.25 volt when using puls charge and this charger does that.
The charger does a perfect CC/CV curve on 18650, but it does not look perfect on 16340 batteries, this has nothing to do with the pulsing.

An you are wrong about driving a led at double current, half the time. This has for many years been done this way on 7 segment displays, except the ration is higher than two.

 

[45/70]

The charger does a perfect CC/CV curve on 18650, but it does not look perfect on 16340 batteries, this has nothing to do with the pulsing.

Well, maybe it's my eyes, LOL, but it sure looks to me like the current (green) in the above graph fluctuates initially between zero and ~740mA and later, between zero and a lesser value. The voltage (red) also appears to me to fluctuate as much as a tenth of a Volt, or more initially, and then does smooth out towards termination of charge.

An you are wrong about driving a led at double current, half the time. This has for many years been done this way on 7 segment displays, except the ration is higher than two.

Well, you may be correct about 7 segment displays, I have no idea. The only experience I have is with high power LEDS, such as those we use in our lights. With those, I didn't have much luck.

Any link to the Panasonic recommendations for pulse charging Li-Ion cells?

Dave

 

[selfbuilt]

Why wouldn't it be safe? It should terminate just like it would as normal. Would the cell being over discharged cause the runaway charge like was notorious on the Lacrosse BC900 chargers where it was charging at over 2000mAh resulting in a complete meltdown including charger and cells?

I recall some previous discussions here in the old days that it was a bad idea to try to charge over-discharged cells, but I don't recall the specifics as to what the issue was exactly (or which chargers in particular). I gathered it was a general safety concern during charging.

 

[45/70]

I recall some previous discussions here in the old days that it was a bad idea to try to charge over-discharged cells

The reason it's not a good idea to attempt to charge over discharged cells, is there is a danger of the cell "venting with flame".

You really shouldn't attempt to charge "bad" cells. This includes older cells that do not retain their charge well, those that retain less than 70-80% of their original capacity, cells that seem to get noticeably warmer than normal while charging, and cells that have been over discharged. Cells that suffer from the above conditions are likely damaged in some way and should be considered unstable.

Cells that have been over discharged in particular, are prone to copper shunts having formed across the separator. This is also often the cause of high self discharge, as this is basically a short circuit. When attempting to charge cells in this condition, the added energy from the charging process itself adds to the problem and there is the possibility of the cell(s) venting.

I'll also add here that there is no such thing as "reconditioning" Li-Ion cells. They are a one way trip. Attempting to recondition Li-Ion cells just adds more wear to the cell, making them even more unstable, and increases the possibility of encountering unexpected problems, ie. "venting".

Dave

 

[HKJ]

Well, maybe it's my eyes, LOL, but it sure looks to me like the current (green) in the above graph fluctuates initially between zero and ~740mA and later, between zero and a lesser value. The voltage (red) also appears to me to fluctuate as much as a tenth of a Volt, or more initially, and then does smooth out towards termination of charge.

The pulsing does not really change anything in the CC/CV curve.

Well, you may be correct about 7 segment displays, I have no idea. The only experience I have is with high power LEDS, such as those we use in our lights. With those, I didn't have much luck.

There are some limits you has to obey when puling leds, but when you do I have not seen I led that could not be pulsed at higher than specified current.

Any link to the Panasonic recommendations for pulse charging Li-Ion cells?

I do not have a link to that. I have only seen a few specifications.

 

[sspc]

Now that I have mine in hand I reread this review and it is really helpful for a layman flashaholic like myself. Your explanation of the slot channel/charging is appreciated as the instructions don't go into much detail about the different slots.

 

[PirateBoy]

i'm a noob....

would this charger be good for the AW IMR 18350 (red unprotected cells sold here: http://www.cpfmarketplace.com/mp/sh...nternational-***Part-2***&highlight=IMR+18350)?

Everyone says those batteries are best for my jetbeam rrt01, so i need a good charger. thx

 

[HKJ]

i'm a noob....

would this charger be good for the AW IMR 18350 (red unprotected cells sold here: http://www.cpfmarketplace.com/mp/sh...nternational-***Part-2***&highlight=IMR+18350)?

Everyone says those batteries are best for my jetbeam rrt01, so i need a good charger. thx

Yes it will.

 

[ClassicGOD]

Just a quick question regarding charging single AAA battery in i4 v2. According to the manufacturer spec and a graph provided by selfbuilt charging current for single NiMH cell never goes over 750mA and according to Sanyo Eneloop AAA (normal not the 'Lite' type) spec-sheet there should be no problem with charging currents up to 800mA and AFAIK Eneloops have no problem with charging at 1C. So despite Sysmax not recommending it there should be no problem charging single Eneloop AAA in i4 v2 or am I missing something?

 

[HKJ]

Just a quick question regarding charging single AAA battery in i4 v2. According to the manufacturer spec and a graph provided by selfbuilt charging current for single NiMH cell never goes over 750mA and according to Sanyo Eneloop AAA (normal not the 'Lite' type) spec-sheet there should be no problem with charging currents up to 800mA and AFAIK Eneloops have no problem with charging at 1C. So despite Sysmax not recommending it there should be no problem charging single Eneloop AAA in i4 v2 or am I missing something?

That is correct, there is no problem with eneloop AAA on the i4, only with LiIon 10440.