Battery Internal Resistance & Max Current

[Lollandster]

Polymer batteries have a tend being fired on any short or even on over- charge/discharge. LiFePo4 have no this trend...
Just search www.youtube.com for polymer batteries and you will find some very amazing videos.
You should be very careful while dealing with polymer batteries...

Who told you my batteries aren't LiFePO4? Take a better look at the description. I think its only called a polymer cell because it has a polymer laminate case or something similar and not a rigid metal case like many lifepos. Looks like most of Hobbykigs lifepos are pouch cells too.

According to this Headway cells are 3-4mOhm. They should work for you and are very cheap from bmsbattery and greenbikekit.

[Bikemad]

Polymer batteries have a tend being fired on any short or even on over- charge/discharge. LiFePo4 have no this trend...

Check out this post to see what can happen if a LiFePO₄ pack does catch fire.

Alan
 

[Lollandster]

Shorting a battery big enough to power a car is bound to generate enough heat to catch something on fire. If the battery itself doesn't catch fire, everything aroud probably will. Nothing with potential of releasing that much power should be considered fail safe.

[Cornelius]

I think 100mOhm are a sign of a tired LiFePo cell...

I use some 'Hether' 3.3V, 10Ah cells, which have a spec of max 2C cont., and an internal resistance of <= 15mOhm/cell.
I built a 36V, 20Ah pack with these cells; 2p12s, and each 2p cell-pair measures 4-7mOhm, even after 1/2 year use...

When battey cells reach its end-of-life (by normal wear or misuse), the IR will rise, which gives less max Amp discharge, and lower Ah.

[MAGICPIE3FOCUSPOWER]

I like Headway the best.
Value for money and quality.
Don't forget easy to build with screws terminal