tl1000brad

i have a Stock EMaxx 3903 .16.8v , waterproof, with stock motors(titan 550s) and ESC (EVX2)
i want to get better batteries / but rather use better techn. than Ni-mh
can you rig.up a (lipo,A123) battery to stock esc. and will it work without blowing the ESC or motors
i was thinking of running 2S lipo or 3s-A123 .., i know that you need a LVC with the lipo.. but do you need one(LVC) for A123
and the batteries run in Series (right??) Because of the ESC wiring? so i just cannot run more thn 8volts in series,2packs
please respond to my post ..give advice or even suggestion or thoughts..if u r not sure just say so....

chris6414

My Feedback: (10)

It is all about voltage. The ESC won't care what type of battery you have. The battery(LiPo) will care if you don't set the cut off or have some other monitoring set-up to not run it too far. That will kill a LiPo. (2) 2 Cell Lipos, in series.

COMMENTS: Do NOT use LiPo batteries with the stock motor setup in this vehicle.
The EVX-2 speed control is not equipped with low voltage detection

This comment was taken from a E-Maxx add

tl1000brad

so as long as i run a low volt. cut off or alarm and stop running the truck .
. i will be ok to run the lipo battery ???
i think it would be ok to run lipo if only running 2s -is 7.4volt X2 =  14.8v 
so i wont go over 16.8v spec.,right ??

-2s -2pack series ,,, now my other question is ... if i get a big one that has  5000 mah or more like 7500 mah
is there  to much power if the  C rating is high/ B.C. in series -
   like a 35c constant and 50c burst /is this ok or ,
 is there a such thing as too high punch for the stock ESC and motors // what is the limit
ESC specs   click here   http://traxxas.com/products/parts/escs/evx2
Motor specs  click here  http://traxxas.com/products/parts/motors/titan550
- wow i just looked at the motor spec or small info on page . it says the motor is only rated for 14.4volts but the sell batteries with the truck that are higher voltage that that.... wow . seems like they want your motors to go bad .. so you can buy more...

chris6414

My Feedback: (10)

The MAH is capacity and the higher you go, the more energy(time) you have to run until weight makes it not worth it anymore. The C rating is how much power you can deliver to the motor when it calls for it(AMPS). The higher the C, the more AMPs you can pull from the pack and the higher your voltage will stay when under load. Many packs like NiMh, will sag pretty good under load. LiPos have huge energy for their size and the voltage stays pretty stable until they start to get low and their curve drops off fast and can and will damage the pack. I have seen them go into a thermal runaway when the user ran them until they thought it was dead. So hot you couldn't hold it. So, you can put two 2S packs in your truck with a decent C rating(30 or better) with the highest MAH that will fit and still allow the truck to perform the way you want and you will be fine. You only damage electronics when you exceed the "voltage", usually. It's just like a nitro motor. If the tune is lean, the motor will get hot and overheat. When you under C a battery application, the battery can't put out the current the application requires and the battery overheats and voltage drops under load and that is bad for performance. By the same token you don't need 60C batteries for your truck either. As the C rating goes up, so does the price of the packs.

Hobby King is a good cheap source. Can take a few weeks to get them but they have good batteries. Just measure the space you have to work with a fill it up with two hard-case lipos and have fun.

http://www.hobbyking.com/hobbyking/s...case_pack.html

http://www.hobbyking.com/hobbyking/s...idProduct=7224

jake383

good luck

tl1000brad

so to do it correctly ..
i need two .. LVC / one for each battery  correct ? bc. each battery will need monitor'd
because of the series wiring.//  i just plug them into the balance plug  each battery,  then plug in the battery to the esc correct , then turn on truck and goooo like hell .lol /

jocoo26

I'm sorry to wake up an old thread but I'm having this problem. I pulled old Emaxx off shelf (3906 I believe). Has dual 550 titan motors. Works perfectly fine with 2 NiMH batteries. I recently purchased (2) 7.4V Lipo and LVD and it will not run. ESC powers on and steering works, but no forward or reverse. I went back to the NiMH batteries and it works fine. Everyone is saying stock ESC can run lipo but its not working. ANY thoughts??