Single Tesla Battery 18650 Cell Test Results

[kennybobby]

A couple of fellows over at the DIY Electric Car site have purchased and dismantled a Tesla pack to open a module to get an individual cell for testing.

One measured 2.9 A-Hr capacity, which is right in line with some of the Panasonic datasheets found online.

The other fellow measure 3.02 A-Hr using a 10A discharge rate down to 2.55V and a 100mA cutoff current while charging.

They were reported to be from a 'rev B' pack.

tesla model S module for sale - Page 2 - DIY Electric Car Forums

 

[techmaven]

A couple of fellows over at the DIY Electric Car site have purchased and dismantled a Tesla pack to open a module to get an individual cell for testing.

One measured 2.9 A-Hr capacity, which is right in line with some of the Panasonic datasheets found online.

The other fellow measure 3.02 A-Hr using a 10A discharge rate down to 2.55V and a 100mA cutoff current while charging.

Very interesting. They had a much higher cut charge and only tested to 2.55V instead of 2.5V and was still able to get 3 amp-hours. From the follow up postings, these cells came from a Rev B pack with 3200 miles, but they sat at 0 miles for 2-3 months. Still had 3.3 volts in the cells, that's terrific.

The NCR 18650A datasheet shows 3.1Ah at 2C, but with a 59mA cut-off at 25 degrees C
The NCR 18650B datasheet shows 3.3Ah at 2C, but with a 65mA cut-off at 25 degrees C

I certainly can't tell if it is closer to a NCR18650A or a NCR18650B.

 

[okashira]

I tested the cells. They are neither NCR18650A nor NCR18650B. They are NCR18650BE.
I was going to post a thread once I have a more proper test done. This was quick and dirty. We are still working on cell removal.
Ignore the 2.9Ah measurement. That was done on a really old, cheap hobby charger that cut at 3V and is horribly inaccurate...