m1 cell question - RC-Monster Forums

t-maxxracer32 · **m1 cell question -** 12.04.2006, 10:14 PM

hey if i went and got one of my dads old dewalt packs and put together a couple packs is there anything id need to know? also can the ice charge these packs?

thanks alot!

o and what does the "p" stand for in like a 3s2p pack

thanks !

MetalMan · 12.04.2006, 10:22 PM

Your dad's "old" Dewalt packs? Dewalt started using the A123 cells maybe around 6 months ago, so anything older won't have A123 cells.

The A123 cells have a vent on one end (not sure if it is the + or - end), and that shouldn't be covered up. I'll be using sub-c battery bars with a hole in the middle to solder the A123 cells together in a side by side way, so that the vent won't be covered up.

"P" stands for parallel, so 2p is two cells in parallel (twice the capacity and twice the current handling capabilities compared to one cell).

BTW, my PM box is no longer full :D.

zeropointbug · 12.04.2006, 10:47 PM

Metalman, actually apparently the hole (its on negative end) is really for filling the electrolyte. And its just simply filled in with a translucent hard plastic of some sort.

MetalMan · 12.04.2006, 11:48 PM

Yeah, but what if gases were to form inside the cell? That hole could allow the gases to vent out, as long as the temp. is hot enough or the pressure large enough to either melt or push away the blue plastic piece.

zeropointbug · 12.05.2006, 12:10 AM

I don't even think they vent though. You check out there website and they put a 3 inch nail through the cell, and nothing happens just a little puff of smoke out of the nail hole (around it). I don't think anything could ever happen to these things that they would even HAVE to vent, seeing as it you short them out they just get hot for several minutes, and thats it, they are so safe. I will be direct soldering my pack (not recommended) with bars, but seeing as there is lots of room to solder, i will not solder over the hole... JUST in case.

t-maxxracer32 · 12.05.2006, 01:09 AM

you guys knwo way too much lol

and metal man i might end up pming you soon when i find out if he has newer dewalt packs!!
so can the ice chrge them?

MetalMan · 12.05.2006, 01:24 AM

Any charger can charge them (even NiMh), but chargers that aren't made to charge them will have to have the charge manually ended when the pack reaches 3.6v/cell. I'll be using the ICE to charge my packs, and will manually terminate the charge, until I get a charger that is able to charge these packs.

zeropointbug · 12.05.2006, 01:48 AM

Why would you charge it with a NiMH charger? You would only get about 80% charge if you cut it off right when it hits 3.6 volts. The need to be charged using their chargers which use CCCV (Constant-Current--Constant Voltage) which when it hits 3.6 volts, holds it, then the current dies off until hits 50mA then charge can be cut off. You can also charge it on a Lithium charger with the new Lipodapter

Or you could get a good lab quality power supply if you are willing, BK Precision 1696. You could charge any battery with this bad boy. $330 Not for everyone.

crazyjr · 01:58 AM

He means a Lipo charger with a set 4.2v per cell (cut-off), as these are 3.3 to 3.6 v per cell

MetalMan · 12.05.2006, 02:02 AM

Quote:

Originally Posted by zeropointbug

Why would you charge it with a NiMH charger? You would only get about 80% charge if you cut it off right when it hits 3.6 volts. The need to be charged using their chargers which use CCCV (Constant-Current--Constant Voltage) which when it hits 3.6 volts, holds it, then the current dies off until hits 50mA then charge can be cut off. You can also charge it on a Lithium charger with the new Lipodapter

Or you could get a good lab quality power supply if you are willing, BK Precision 1696. You could charge any battery with this bad boy. $330 Not for everyone.

I plan on doing a "manual" CV phase, where I will lower the charge current to keep the pack close to 3.6v/cell.

Just FYI, the LiPo Dapter does the same thing I was talking about - it cuts the charge when the pack reaches 3.6v/cell, it doesn't do CV.

starscream · 12.05.2006, 06:23 AM

Quote:

Originally Posted by zeropointbug

Why would you charge it with a NiMH charger? You would only get about 80% charge if you cut it off right when it hits 3.6 volts. The need to be charged using their chargers which use CCCV (Constant-Current--Constant Voltage) which when it hits 3.6 volts, holds it, then the current dies off until hits 50mA then charge can be cut off. You can also charge it on a Lithium charger with the new Lipodapter

Or you could get a good lab quality power supply if you are willing, BK Precision 1696. You could charge any battery with this bad boy. $330 Not for everyone.

The Dapter charges the M1's to around 90% which should actually increase the life of the cells.

The LipoDapter works with Nihm/Nicad chargers but I suppose you could also use it with a Lipo charger. I've been using my Dapter for a few months now and I'll say that the $40 investment was well worth it as well as giving my Astroflight 110D another use other than collecting dust.

Its my understanding that the M1 cells have silver tabs that are not good for soldering. So, I would not recommend soldering on these cells but if you must, just be careful. I use the solderless power tubes so soldering is not even a consideration for me :017:

t-maxxracer32 · 12.05.2006, 07:57 AM

well if i do do this i will definetely look more into it. dont want to waste my time building a pack and then end up ruining my charger or the batteries because of it. will the lipodapter fit my ice chargeR? i would charge it manually buit i always forget that im charging something... how long would it take to charge these with the ice? still like only 15 min? cause if so i think i can remember that.

MetalMan · 12.05.2006, 10:15 AM

You can charge up to 4s2p with the ICE. With the 2p setup charging at 8amps, it would take about 35mins. In 1p, it would take half that time.

zeropointbug · 12.05.2006, 01:00 PM

You mean you are going to sit there will doing a CV phase! :026:

EEK, i would rather spend $80 on the A123 charger, it will charge your pack in 15 minutes. Of course it only charges up to 3 cell at a time, you also need a balancer cable.

T-MAXXRacer32 - If you don't have any packs, i would if i were you just buy there Hypersonic packs, they have 2s1p, 3s1p, and 2s2p packs, from there you can make pretty well any combo of total pack power/XsXp. You could if you wanted buy a new DeWalt 36 volt pack and manually make a pack, just put an Anderson balancer cable on, and use A123's chargers for 15 min charges.

It's up to you.

Serum · 12.05.2006, 01:09 PM

Metal is a patient person. fyi, he has got a great knowledge on lipoly cells. and he likes the best bang for the buck.. I am not surprised he plays his own current adjuster.

He has got the cells, so why should he buy new ones? His question was if he could charge the cells with the ice charger, which he can.