Lipo specs?

[ReddyWatts]

What are the specs for different lipo batteries? I want to try adding a few brands to FeCalc.

Brand?
ohms per cell?
weight per single 3.7 volt cell?

[ReddyWatts]

The normalized resistance of the Lipo cell is HALF of the resistance of the NiMH cells. This means that for 20A+ loads, the Lipo output voltage will be higher and the internal losses [heat!] will be half of the NiMH. As a side, note that the Lipo resistance decreases with discharge. This seems common with LiPo, and apparently is a function of the cell warming up. The upsweep on the NiMH curve is typical of Ni* and contributes to the "brick-wall" effect at the end of discharge.

CELLS _______MAH_ OHM__ WGT.____volts

Lipo 3200-20C 2990_ .0025 __1.1 oz__ 3.7

NiMH 3300* __3210_ .0050 __2.2 oz__ 1.2

Plug the Lipo numbers into FeCalc and see if it comes close. For a 2s enter 2 cells, 4s enter 4 cells..............

[ReddyWatts]

Will someone post your setup and results for a fiegao motor running on lipo's with direct drive. I want to check or adjust the generic lipo numbers for FeCalc. I emailed some battery shops and they do not want to give up their (ohm) numbers for any of their packs. It was no problem with NiMH batteries, but it is top secret with lipo's.

setup:
motor and winding
lipo/?s / mah / brand
prop
hull
number of battery connectors and length of wire.

results:
Speed
amps
battery/final temp

[andym]

Reedy hope this helps
setup; 5s, 4800, elite . Polyquest 5s, 4500mah, 30c = 125deg F
m447 prop
toysport triton
6mm gold bulletts, 6" wire to esc
84.5 kmh
peak 130a
145deg F

[SJFE]

I will suply you with data Saturday afternoon. It will be a Kb motor however.

[ReddyWatts]

AndyM: which motor and turns?

SJFE: a KB45 will be great.

The more setups with results I get, the better.

Thanks!!!

[NorthernBoater]

I can get you some data next week after I run.

[Doozie870]

How do you measure ohms on either chemistry, my meter (standard type) sends voltage out and measures the drop, Im worried it would blow up if I tried to hook it to a pack.

[ReddyWatts]

You have to use special equipment to read the actual ohms(impedance) of a battery. A regular volt ohm meter will not work. We have people that use this equipment at work but I do not have any lipo's to test, so I am going to try and use FeCalc and adjust the battery ohms until the calculations match the results of your tests. Then hopefully use that data to find other lipo setups.

I did find one 3300 lipo that was .0025 ohms per cell. I want to see how close FeCalc figures this to an actual setup.