Hey guys,
Im new to the whole lipo thing and I was just wondering what the main difference between NiMh and Lipo is. Im lookin to get a lipo setup for my mamba monster system on my emaxx and castle creations says 4s is the sweet spot. It also says that it will only gain 5mph top speed, so is it worth paying the few hundred dollars for a lipo setup???? Please help me out and let me know.
Thanks

14.8V 4S LiPo isn't a bad thing compared to a 12 Cell NiMH Pack (weighs more and less run time)

and top speed depends on the gear setup to,besides watching for overheating because of the wrong gear setup

you can slap 2 14.8V 4S LiPo's with good Mah and get longer stronger run times
with the sweet spot of a gear setup
so yes well worth it
just watch out for the draining of a lipo can't go under 3.3 volts and hot is a bad thing
whereas a NiMh can (uses no memory and heat don't harm at draining times) and can be charged at anytime
EXAMPLE; you don't remember if you ran them dead or half full
so recharging them anywhere in that state won't harm them...

and yes lipo in the end costs more..but has better current drain..
it's kind of like fine tuning the motor once you go lipo...lol

So i will actually get more power out of them??? Also what kind of charger do you recommend???

yes the lipo will and is lighter....
if you can get your hands on a Imax B6 lipo charger or something along the same range that would be the way to go
ebay,hobbyking or Dealextreme.
would be the cheapest but longer shipping time
but if you find a charger in US you pay more
after all there all made in china...lol

Lipo is better about holding voltage while discharging and will be faster longer than NiMh. You can charge lipo as many times a day as you want unlike NiMh thats limited to just a few times a day. Lipo doesn't have the high internal resistance that NiMh does and since lipo is not converting some of its energy into heat like NiMh does (the reason NiMh gets hot when run), you'll have better run time. Lipo is lighter as well so if you have room, you can use a larger capacity (mah) lipo as well.

Lipo requires a balancing charger. This is a popular charger, that has a pretty good rep -

http://www.hobbypartz.com/thac6smbachw.html

What about the horror stories of LiPo fires? Am I just paranoid or is your (several hundred dollar) car likely to catch fire if you aren't careful?

Lipo fires are overhyped.

A lot of the fires were deliberately staged (Utube) for one reason or another. The lipo material itself is way safter today then a few years ago. Most probs or incidents happen while charging and are typically user error - charging as the wrong chemistry, not hooking up balance wires, going off and leaving it unattended etc.


Get educated about lipo, use them kinowledgeably and respectfully and you'll prob never have a prob.

Just get some quality hard case LiPos and be done with it. I put off getting LiPos and was using NiMH in my son and I's SC10s. We recently picked up a couple of 5000 mAh LiPos and the difference is night and day. One car is RTR with the Reedy 3300kV motor and the other has a Castle Sidewinder 5700 combo and they RIP with the LiPos. Don't even waste your $$$ on old battery technology.

If top speed is your concern, battery isn't the best place to look.

The difference between NiMh and LiPo are in chemistry, and physical makeup.

The part that matters to you, is internal resistance. LiPo batteries have far less internal resistance than NiMh, this means there is less voltage drop under load.

Also, the discharge curve on LiPo batteries is flatter. A fully discharged LiPo is 3.8v, instead of .9v for a NiMh cell. The NiMh cell loses 1/3 of it's voltage, while the LiPo loses only 1/5th. This means your car slows less before the battery dies.

NiMh cells use Nickel as one of their electrodes. And they use metal cans to support their cell structure. LiPo batteries use lithium as their electrodes, which is very, very light, and they're enclosed in plastic, which is also light. Which means for a given physical size, LiPo's are lighter. For a given capacity, they're smaller.

What you didn't touch on, was what was your goal?

i still use my orion 3200 carbon lipos that i bought back in 2006. it was one of the first car specific lipo batts you could buy back then. i still get a full charge (8.4V) and full capacity (3000-3150 mah.. my cutoffs are set to 3.0V/cell) even after 4 years and 400+ cycles. Lipos are a lot safer some make it out to be.