Thread: Discussion IR readings?
View Single Post
Old Nov 23, 2010, 04:14 PM
mrforsyth is online now
Find More Posts by mrforsyth
Registered User
So. Cal.
Joined Oct 2004
9,032 Posts
For a rough indicator of performance, I divide 12000 by cell capacity to get what I consider to be a very good internal resistance number. e.g. - for a 2000mAh cell, any number below 6 (12000/2000) is quite good in my book.

As Wayne indicates, charge state does not matter much. However, temperature matters greatly as lipolys have a negative temperature coefficient (hotter = lower internal resistance). As such, I always measure when cells have stabilized at room temperature (72 deg F) for at least one hour. If I want to track performance over time, I perform the measurements at 3.85+-.05 volts per cell and 72 +- 1 degree F.

Mark
mrforsyth is online now Find More Posts by mrforsyth
RCG Plus Member
Reply With Quote