m1 cell question
 

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 !

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.

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.

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.

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.

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?

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.

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.

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

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.

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:

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.

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.

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.

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.

Oh BTW, the tabs on the M1 cells are a nickel alloy, easily solder able. The cell cans are aluminum. Which is tougher to solder, the ends aren't too bad though. They have some sort of coating which makes solder possible.

ty serum!

and zeropoint- the whole poin for me doing this is cause i pretty much have everything. for rigth nwo i dont wanna spend any more cash on rc since ive already put like 400 into it in the last couple weeks. maybe later i will do that though thanks!

IMO, $80 is a rip off for the A123 charger. I can get an Astroflight 109 for $90, and that will charge 10s A123 cells. Then, I can mod the 109 to charge to 3.6v/cell AND do the CV phase, or I could charge 10s A123 as 9s Lipo (with a slight overcharge). Supposedly Astroflight is working on a chip that will allow for the charging of A123 packs.
Otherwise, the CV phase shouldn't be long with these batteries, considering that when the voltage reaches about 3.65v the cell is almost completely charged (indicated by how the cell will cause the voltage to skyrocket when a CC charge is going on).

Well, for my 5s2p pack on my power supply charging, i charge them in 27 minutes. I get to CV phase at roughly 20 minutes, and then the current is still over 5 amps for several minutes, and negative exponentially dies off. So it's i guess over 85% charged at beginning CV phase.

Okay, the cheapest way to get going with A123's is buy a dewalt drill pack, or buy A123 Racing website. Then just buy the NEW Lipodapter which works with A123 cells, and charge is using a lithium charger if you have one or whatever.

man all this stuff you guys are saying... sheesh... ive got alot to learn... what is the cv phase?

cv=constant voltage. cc=constant current.

hm... sounds cool...

Did you want to know more? I was brief because I tend to ramble...

I agree that $80 for a 3S charger is over priced. The FMA Direct CellPro 4S charger can now Charge & Balance A123 packs at 3Amp for $60. However, The Astroflight 109 for $90 will charge Lipo's and A123's but it will not balance them. Are you planning on configuring you packs with balancing wires? I find the whole balacing connector differences quite a PITA. It seems everyone has their own connector and I'll have to get an adapter if I want to use someone else's charger/packs.

I do plan on adding balancing taps, Polyquest/Hyperion style (what all of my packs use). The Hyperion/Polyquest taps seem to be the most popular, and from what I have seen, are the most popular.

well i just dont knwo what it is. i didnt know if it was a charging method or what lol. i need to know all i can before i go into actually doing this. has anyone made a faw or any kind of good sticky thread i can go look at? i serisouly have no clue on most of this..

thanks for your guys help thoggh!

Well, to make it simple;

A Constant current charge will vary the voltage to be able to push the set amount of current through the battery. This is how NiMH batteries are charged (with an extra step of detecting the peak voltage before the voltage starts to come back down). Simply: Current is constant, voltage is variable.

A constant voltage charge will output a steady voltage and the battery will pull whatever current it can. If you try to charge a depleted battery with a constant voltage, it will draw a HUGE amount of current, which would destroy the battery. Simply: Voltage is constant, current is variable.

A Lithium charger starts by charging at a constant safe current until the pack reaches 4.2v/cell (the battery voltage will rise as it gets charged). If you keep going at a constant current, the voltage will increase beyond the safe battery voltage range. So, the charger switches to a constant voltage charge. The charger maintains this voltage, but the charge current falls slowly until it is near zero, and the charge is done.

kinda get it but idk why youd have to do a cv phase with the a123 cells but thanks for your explanation on it!

Also, maybe note worthy is the fact that the CC and CV are maximum values. Say, for A123's the max recommended voltage is 3.6 (3.8 MAX, 4.2 burst), and the charge voltage is at 5 amps. The charger will never breaking both rules at once... it will pump 5 amps in until it hits 3.6 volts, hold it there, lets the curent die off until no current at all (50mA is cutoff for A123), at which point charge is at 100% SOC (state of charge). Like Brian said.

But the think about A123 M1 cells is that they are very forgiving. You just can't give them a grudge against you. They are very durable to overcharge, under voltage cutoff, and brief short circuits (i did so myself, the tab just disappeared from a flash of light :017: )

Any other questions?

well i would ask for certain specs on how to charge but im going to wait for that untill i make the actuall packs. it may not be till after xmas so theres no use in me asking now.

i do have an off the topic question.. i have these 2 crazzy 3000 packs (6 cell) when i get my brushless i will never use these cause well... itd be pointless i have 3 gp3300s(that im going to convert each into 8 cells) and i have 2 ib3800s. so my question is what would happen if i took these 2 packs and made one? idk if id have to solder them together or what. but it would just be a fun pack to play around with. would it become a 14.4 3000 pack? or 14.4v 6000 pack? not really sure how that works


thanks guys!

I don't know if this is what you meant, but I wouldn't mix the batteries (GPs and IBs). As far as making a big 14 cell (or other cell count); it works fine. I have a single 14 cell GP (from RadioShack) pack for my Revo. I basically took two 7 cell rows and put them on top of each other to form a "brick" pack. If you keep the packs seperate, you have to use a Y adaptor to hook them together. But if they are all in one pack, you don't use a Y connector, just the bus bars between each cell. Less connectors and wiring means lower resistance.

If you hook all 12 cells in series, you'd have a 14.4v 3300mAh pack. Series adds the voltages, parallel adds the current.

no i mean that i have 2 of the same 3000 packs. they both arre 6 cell and both suck. imthinking about combining them to make one 12 cell pack.

lmkhow that would work! gimme a link to the y adapter?

thanks!