Li-Fe batteries
 

From my own research it seems like a step forward from Li-Po, but my local hobby shop says they have about as much power as NiMh batteries. Anybody used them? how does power compare with that of Li-Po. I'm running mostly stock classes so power is certainly helpful.
Thanks

Volts = Revs

2s life - 6.6v
2s lipo - 7.4v
3s life - 9.9v
3s lipo - 11.1v

Cheers

Those numbers are right on, and LiFe is slightly more powerful than typical Nimh 6-cell packs even though it has a lower nominal voltage, because the voltage will not sag like Nimh does. Good Nimh packs may hold higher voltage than a LiFe 2s, but they will deteriorate at a faster rate and after 50 runs or so the voltage will sag down to lower levels. You definitely want to go with lithium packs of some sort, I would only use LiFe if I raced a class where I had too much power with 7.4V. They are a good choice for someone who does not want or need a power upgrade but wants the benefits of Lipo. I, for one, am always up for a power boost in any way I can find it!

LiFe packs are usable in open or mod classes since you can use a higher Kv motor to compensate for the lower voltage.

In stock classes or spec class those batteries are at a disadvantage unless you can gear up without overheating the motor.

Running LiFe is close to running NiMh weigh wise, you lose the lighther weight advantage you get from running lipo.

This isn't correct.

A 2100mah LiFe RX pack weighs 106g (from http://media.hyperion.hk/dn/fg3radio/)

The Team Losi 2000mah LiPo pack weighs 86g (http://www.amainhobbies.com/product_...ck-74V-2000mAh).

I couldn't find the weight on a comparable 5 cell NiMH hump pack, but this pack weighs 159g a will provide similar longevity:

http://www.amainhobbies.com/product_...mAh-Losi-Style

One thing you will give up in relation to LiPo is size. The LiFe packs are considerably larger for the same capacity.

It is not correct. The 2100mah 2S Life I bought acually weighs more than a NiMh rcvr hump style pac. I have this LiFe -

http://www3.towerhobbies.com/cgi-bin...&I=LXYAS9&P=ML


Its weight is listed as 143gr - I weighed mine on my postal scale and it weighs 142gr. I weighed a 5 cell NiMh hump pac and that weighed 124gr - 1600 HPI hump pac.

I note in looking at the Hyperion data, they have different weights for the same 2100mah 2S LiFe pac - the one they label as rcvr pacs they list as 106, p/n HP-FG305-2100-2S. Then they list the same p/n under TX pacs but give the weight as 155.2g. It can't be both.....

http://media.hyperion.hk/dn/fg3radio/


Hyperion has a mistake somewhere and IIRC on RC Groups someone said the higher weight is the correct weight.

don't see much racing LiFe's because racers cant be giving up .4v per cell + extra weight. I'm about to move over from NiMH to LiFe for my bashers, LiFe are perfect for bashers - more cycle life, safer, faster charging, and the batteries themselves are harder to damage and less volatile when they are damaged.. etc etc

i'm putting 2300s 2s2p (and maybe 3s2p) in a hpi e-firestorm, and 2s1p in a brushless mini-t. If all goes well i'll be converting my whole stable over.. nimhs to life's do not pass go and do not collect lithium polymer.. oh and eneloop nimhs for my tx :D