AW IMR 18650 in sight?

[AW]

RC people find some interesting fact about these safe chemistry cells that they seem to self balance themselves to within 0.01V when used in series. If the voltage output of the serial charger is within spec., chance of overcharging individual cell is slim. The ability of accepting a fast charge up to 3C is a plus. This means charging not-so-balanced cells in parallel will be fine as well ( the initial few seconds of current flow between cells is usually high for unbalanced cells during parallel charging ).

I was more concerned with overcharging one of the cells if charged in series because the charger has no way of knowing what the individual voltage of each cell is. I assume these cells will last longer if charged individually.

 

[ampdude]

I really need the 18500 and 17500 cells more than any other size, I hope these are on the way next. 17500's for my EDC and 18500's for my bigger lights.

I'm sure a lot of people would appreciate some in 17670 as well. I wouldn't mind one to run an E-series led head myself.

 

[mdocod]

Would charging (3) IMR18650's at a time in series be dangerious?

This is the charging method for Wolf-Eyes Storm, Boxer, and M300 lights using their battery cartridge.

YES AND NO.... Please pay close attention:

Lets separate the question into 2 simplified pieces:

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"can I charge IMR18650s in series"

Yes, provided you use a charger that will terminate the charge on it's own, in a reasonably manner (4.20V per cell or very close to it). And provided you, the user, step in once every few cycles and make sure the cells are within ~0.05V of each-other; and if they are not, take the time to balance out the cells by charging them individually, or identify an underperforming cell and swap it out. As AW said, these cells seem to do quite well in series charged applications and should work fine....

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"can I charge 3xIMR18650s with a wolf-eyes charger"

No, the wolf-eyes charging system relies on a high quality reliable protection circuit (found in AW and Wolf-Eyes cells) to terminate the charge. Installing these "IMR" cells in the 3 cell magazine of the wolf-eyes system, and charging them, would just create a major problem. It would just keep on charging the cells, until they were severely overcharged. While LiMn chemistry cells are considered "safe," this would not be good for them in any way, I would not be surprised if they "popped" from heat build up and pressure. (not necessarily a flaming explosion, but possibly a "rupture" with venting gas etc etc)

With that said, you could take a charger that terminates properly, and splice it into the plug for the wolf-eyes 3 cell battery adapter, and use that instead with IMR cells. This would eliminate the issue of severe-over-charging and provide a pretty solid setup....

-----------------

Eric

 

[cchurchi]

Thanks for the information, I was unsure if the Wolf-eyes 3 X 18650 battery magazine charger stopped charging at 12.6V or relied on the batteries protection circuit to stop charging. Now I know.

What about the Wolf-eyes 2 X 18650 parallel charger? Does that charger also rely on battery protection to shut of current flow? I think I have charged some unprotected 14500's using this charger with some spacers....

 

[mdocod]

Thanks for the information, I was unsure if the Wolf-eyes 3 X 18650 battery magazine charger stopped charging at 12.6V or relied on the batteries protection circuit to stop charging. Now I know.

What about the Wolf-eyes 2 X 18650 parallel charger? Does that charger also rely on battery protection to shut of current flow? I think I have charged some unprotected 14500's using this charger with some spacers....

I'm pretty sure that all of the wolf-eyes chargers rely on a protection circuit for charge termination. Just stick to protected AW and WE cells on those chargers.

 

[ToTo]

How do these IMR cells perform concerning outside temperature compared to protected li-ion cells?

 

[ampdude]

How do these IMR cells perform concerning outside temperature compared to protected li-ion cells?

I was about to ask AW this exact same question.. especially regarding extreme cold environments.

 

[PlayboyJoeShmoe]

I just harvested 3 IMR 18650E from a pack to a Ryobi tool of some sort that my buddy bought.

I can always use more 18650!

And if these are not QUITE as dangerous as Li-Ion so much the better!

BTW two of these showed 3.81 and one 3.82 so I'd say they are matched pretty good!

 

[New_World]

When shorted. The IMR cells can dump up to 20C current which will melt the shrink wrap and damage your setup due to external resistance. The cell will be killed as well. NiMH/Nicad/Lead Acid cell all behave the same when shorted. No explosion / vent with fames with the safe IMR chemistry. A pcb will add up to 60mOhm resistance to the cell and hinder the performance considerably.

thanks for the reply AW.
I have been looking for this answer to quite some time.
Google always leads me back to CPF. =)