I am wanting to upgrade from my nimh batteries & lipo is not an option because of the fire hazzard, yeah I know...the first thing people always say is they're fine if you treat them right! it's not that simple for me because I am paralyzed & cannot use my hands & I live in a nursing home so I absolutely cannot chance a fire! sometimes my batteries get put on the charger & left til they're done so I really need a battery that's stable. I want something that has a substancial power gain over my 7 cell nimh batteries, I read somewhere that someone ran a 9.9v lifepo4 & it was a big performance gain over a nimh. well, I have a mamba max pro esc which is capable of running up to 25.2v so I've been looking at the zippy flightmax 4200mah 13.2v 4s lifepo4 & the 2300mah 4s a123 batteries. the lifepo4 batteries are a flat cell & the a123 cells are round. the lifepo4 are either 4s1p or 4s2p & the a123 is 4s1p, I don't understand the difference, do each have their advantages/disadvantages? or are they just for different applications? I looked up my motor (velineon) & it's 65a continuous current & 100a burst. here are links to the two batteries I've been looking at & I'm not sure which one to get, any suggestions? the lifepo4 zippy battery will fit my slash easier but a small chassis modification is not a problem for a big performance gain. any advice or info will be much appreciated!

http://epbuddy.com/index.php?main_pa...products_id=22

http://www.hobbyking.com/hobbyking/s...dProduct=14067

Velineon 3500 motor is only rated for 3s lipo (11.1v)

If you are planning to run Lifepo packs you should be looking for the 3s size (9.9v)

Something like this pack would work well

http://hobbyking.com/hobbyking/store...dProduct=10310


You will need to change the battery connector to match your ESC

I would also suggest you change your ESC battery cutoff voltage to suit the Life pack

Cheers

thanks for the info! I also checked the max rpm & it's 50,000, a 3500kv at 13.2v is 46,200 rpm. I hope that means it'll be okay. I really want as much power as possible! anyways, thanks again for your reply & info! I appreciate it!

4s life pack is actually 14.4v (3.6v / cell fully charged)

Its not the voltage that will kill the motor its the current

Cheers

I've ran my 4s zippy flightmax lifepo4 battery several times in my slash & so far no problems & it runs great! it's still geared a little too high (21/86) & it gets a little warm after 15 or 20 minutes but not too bad & the temp outside was well over 100 degrees. I'm gonna put about an 18 tooth pinion on it & if it still gets too warm I'll put a heatsink with a fan on the motor.
http://youtu.be/Q42xVonAVys