Feigao 8XL + 9920 + 6S (a123 cells 19.8V)

[TruckBasher]

Do you think this I can run this system with my E-MAXX?:030:

HB lightning pro diffs
44/16 gearing
Slipperential
big joe tire
GMAXX Chassis
9920 with fan
Feigao 540C 8XL

I'm about to complete my very first EMAXX:004: ...and i plan to run 2 x 3s2p a123 cells (cant afford xtrema at the moment and stuck with cell pro). Let me know your concerns...

Reason for wanting 6S: Brian's speed calculator indicates a top speed of 25mph (no balloon factor) at 5S. I know it would range to 30-35mph at most but i want more:028: ...if possible :036:

[Serum]

Seems like a good setup to me!

Has anyone got some real life discharge graphics of these cells?

[TruckBasher]

Thanks....I just read a couple of thread that 6S on 9920 is too much.....

[Serum]

nope, within specs.. you are not gearing it over the moon, so you should be fine..

[coolhandcountry]

I thought the pro diffs had a 4.3:1 ratio. That will gear you down right much.

[TruckBasher]

I see....so I'll go with with 6S then...thanks Rene and Leroy

[jollyjumper]

you're sure about the 4.3 diff's?
cuz we wouldnt want you ending up with a undergeared truck.:007:

[squeeforever]

Yea, thats why he is only getting 25mph on the calc. Go with the standard diffs with the 3.31:1 ratio.

[MetalMan]

Here's a discharge of the A123 cells:
http://www.rcgroups.com/forums/showp...98&postcount=1

TruckBasher, I'm running 5s2p (of A123 cells) in my Revo, and it's a lot of power! 6s would be pretty insane.

[TruckBasher]

@Metal, what motor/controller do you have? I initially planned on getting 3s2p+2s2p, I already have the pricing from MaxAmps just thought of putting more voltage to my can. I'm wondering how insane is insane?:004:

[MetalMan]

Mamba Max and Feigao 540C 7XL. I believe that "insane" is in the eyes of the beholder. It's definitely enough to at least keep up with the nitros (that use a 2-speed), but it doesn't wheelie much (it does occasionally) because of the center diff.

I went with 5s2p (3s2p + 2s2p) because there are 10 cells in the Dewalt 36v power tool battery packs. On Ebay you can get these packs for ~$100, and then they are broken down to harvest the cells, and a new pack can be made. I'm guessing Maxamps would charge at least $250 for 3s2p + 2s2p.

[TruckBasher]

Nice...

Well, austin told me it is around $220++... I could get 2 sets of Dewalt pack. To bad for me, most of the people selling the dewalt 36v pack on ebay doesn't ship outside the US. Though i can dig up some people selling but with a higher price...

BTW, can you post a picture of the loose cells from the dewalt pack?just want to see. I found a store here that sell hundred of different battery cell for different application

[MetalMan]

I would only recommend buying the Dewalt 36v packs and making your own packs if you have experience in battery building. I had to develop my own method for making stick packs, and it is quite time intensive to do so my way.

[BrianG]

Do you have any pics/instructions on how you do it? I was thinking about going with those M1 cells for my Revo (6s2p) and was mentally toying with how I was going to do it. It's nice to get some ideas for others - no sense re-inventing the wheel. :)

[MetalMan]

Unfortunately I didn't make a tutorial on how to do it. It takes so much time without taking proper pictures, and for my last pack I was under some time constraints (needed the pack done ASAP). If I can cough up $100 more, then I can get another pack and make the tutorial.