Batterys
 

o.k. a question I have of Kokam 7.4volts 1200 mah 2 cell pack would it be the same as a 7.2volt 1500 mah car battery 6 cells? I know this might seem stupid but I have to ask anyway. thanks lmalone

RE: Batterys
 

Not a stupid question at all. LiPolys are expensive, and picking the wrong pack for a particular application can be costly.

Whether the LiPoly will be a good replacement for the NiCd depends on the situation.

While the LiPoly has a little more voltage, and almost as much capacity as the NiCd, it's also physically much smaller, and can't handle near as many Amps as the NiCd. Try to put that pack in a 1/10 scale buggy, and you'll turn the buggy into a smoking heap in no time. The pack will overheat, and probably burn inside the car, because the load is more than it can handle.

The LiPoly might work well as a replacement in a smaller airplane, but again, it depends on the plane.

What in particular are you trying to power with LiPoly.

RE: Batterys
 

Matt, Im just trying to make sense of all this battery stuff. I was thinking the two batteries I was talking about seem to be matched by label but understanding that is going to take some thinking on my part. My thought was with my Electra sail plane that used a 6 cell nicad pack the same as a rc car I was thinking iI could use the poly cell in it's place? As you can see I have a lot to learn. I just got my ElectricCalc program maybe I can learn something from it. also as lone as we have people like yourself all of the new people like my self just might learn something, thanks lmalone

RE: Batterys
 

Let's use your Electra as an example:

For the Electra, the voltage of the LiPoly is perfect. Problem is, the Electra's motor draws 25-30 Amps at full throttle. If you check the documentation/advertising/labeling for that 1200mAh LiPoly pack, you'll see a "C" rating. That tells you how many Amps the pack can draw as a multiple of its capacity (C is for capacity, thats good enough for me, oh capacity capacity capacity start with C!!!!! :D). Okay, enough channeling Cookie Monster...

Anyway, the pack will be rated at something like 10C, for example. To figure out how many Amps the pack can handle, multiply the capacity of the pack times its C rating. 1200mAh times 10C is 12000mA, or 12 Amps.

We have a motor/prop setup that draws 25-30 Amps, and a pack that can only handle 12 Amps. You can probably guess already that it's not going to work.