Charging A123 M1 Cells?

[BrianG]

OK, thanks. It makes sense now. The cutoff is easily done with the FET, I just couldn't understand how it would do the CV stage.

You think that the CV stage is good for only 10% of the charge? When the pack reaches 4.2v, the current is still at the full charge current, but then slowly falls. I would think that's at least 15-20% of the charge. For instance, with my 2s2p emoli, I get about 4500-4800mAh when it hits the CV stage and I end up with a total of ~5800mAh put into the cell. That's at least 17% of the charge missing if I were to pull the pack off at that point. Unless emolis act different than M1's or Lipos?

Even if it was only 10% due to the lack of the CV stage, that's 10% less pack capacity. I don't know if I'd like that. I understand the cost factor, but the price of these packs, sometimes it's worth getting the "good stuff".

[starscream]

The "Dapter" cuts the connection to the charger when the cuttoff voltage is reached. Yes, you have to manually count the number of blinks per cell. I don't find it hard to count to 6 though :005:
Counting blinks beats the $200 price tag for the Xtrema, especially when I have never used the cells before. If I invest more into the M1's, I'll reconsider the Xtrema.
My multimeter typically shows my 6S pack at 20v when the "Dapter" cuts the charge. Thats 92.5% capcity in 16 minutes at 7.5 AMPS. I can live with that for now. I sent my Xtrema back because I couldn't justify keeping it when the $40 LipoDapter charges my packs just fine.

[jhautz]

Yea but in the instructions I found on line they not only talk about counting the blinks for the cell count, but also when the red light blinks 3 times then you push the button and hold it until it blinks again and then when the green light blinks 3 times you push it again and then you are in M1 mode or something goofy like that. Then how are you sure that you are in M1 mode???? I'm sure that you probably get used to it since you have to go through the whole routine of putting it into M1 mode every time you hook up a battery.

I'm sure it is actually much simpler than the instructions make it sound. All I'm saying is there is more to it than counting the cell count blinks. And from what I read there seems to be a pretty good chance for error.

Maybe I'm just paranoid from Lipos:p.

[starscream]

Originally Posted by jhautz

Yea but in the instructions I found on line they not only talk about counting the blinks for the cell count, but also when the red light blinks 3 times then you push the button and hold it until it blinks again and then when the green light blinks 3 times you push it again and then you are in M1 mode or something goofy like that. Then how are you sure that you are in M1 mode???? I'm sure that you probably get used to it since you have to go through the whole routine of putting it into M1 mode every time you hook up a battery.

I'm sure it is actually much simpler than the instructions make it sound. All I'm saying is there is more to it than counting the cell count blinks. And from what I read there seems to be a pretty good chance for error.

Maybe I'm just paranoid from Lipos:p.

I see what you mean about the process but after doing it a couple times, its easy. I also understand about being paranoid from charging Lipos :eek:
Thats why I like these cells so much, they can take a lot more abuse than Lipo cells. I have only done a few charge cycles on these cells but there haven't been any errors thus far. The only thing I noticed is that the "Dapter" only see's 5 cells after I use the pack so I have to increment 1 cell every time I charge. I am also hearing that these cells tend to not accept a charge once they have peaked. I'm not sure how that would work out if you left them on the charger for an extrended period of time but gives credence to thier durable nature.