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

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:

Seems like a good setup to me!

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

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

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

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

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

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

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

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.

@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:

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.

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

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.

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. :)

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.

these packs don't need an LVC?

Not really. They can handle a low discharge voltage (2v rated, 1v minimum). When they run out of "juice" they pretty much dump noticeable. At that point you should remove your finger from the throttle trigger.

Yep, no LVC needed. That's what made me decide to go Li-ION. Almost as good as Lipo but less maintenance and care needed.

I have less experience on batts. I am worst even on NiMH side by side. I guest I should just buy the packs for now. The price I have to pay for being worst in assembling batt packs.

With all said and done. I think I will go with 5S2P or 3S2P+2S2P, being noob and all on BL setup.