8Ah batt - 6.1Amps used=??? ... calc range with C ratings

The Cycle Analyst manual says you can determine your range simply by subtracting Amps used from the Ah of your battery. So if you've used 6.1 amps of a 8 Ah pack you have just shy of 2 amps to get you home.

But what if your 8Ah pack is rated 5C?

I have two 36V20A LiFePO4 Headway packs wired in series but haven't "emptied the tank" yet, so I'm not sure how deep I should expect them to go. I'm told they're rated 5C but that real world results can vary. I guess I'm not too sure what that even means. Thanks for your help.

Hi ryan...
Ah capacity and "C" rates aren't directly related... they are with lead acid but with lithium not much. If you have a 10Ah lithium cell for example, at 1C it should deliver 10Amps for 1 hour. 2C would be 20A for 30min. 5C would be 50A but only for 12min... When the cell mfgr specs their cells as eg 5C continuous, means that's about as fast as you want to draw them down (aka continuous power output) before yer starting to shorten their claimed cycle life. Yer packs probably have BMS cards and those should stop your cells from reaching "zero". Diff. C-rates should not change the Ah countdown (countup?) except to speed it up. Not directly related to C-rates, but the higher rates implies you are moving faster, and it actually does require more Ahs per mile as the aero drag becomes more significant at higher speeds.
Cheers
LocK

Thanks Lock! That was very helpful!