In preparation for posting the A123 26650 test results I wanted to briefly list how the lithium-ferrous-phosphate chemistry (“LFP”) batteries from A123 Systems, Inc., differ from the batteries we normally use when vaping.
A123 batteries have several advantages:
- Their low internal resistance means they are able to supply more current before overheating and they hold their voltage up better.
- LFP is the safest of the Li-Ion chemistries. It has a higher threshold temperature for thermal runaway and less violent reactions if the battery does go into runaway.
- LFP offers long cycle life, i.e., it is capable of a larger number of charge/discharge cycles than the other Li-Ion chemistries.
A123 batteries have a few disadvantages though:
- The 26650 is only 2400mAh and the 18650 is only 1100mAh.
- They have a nominal voltage of 3.3V versus the 3.6V/3.7V for the li-ion batteries we normally use. At high discharge current levels the voltage can be down close to 2.5V.
I hope to have the test report for the 26650 posted in a couple of days. I won’t be testing the 18650 as its capacity is so low. For more information about A123 technology, LFP chemistry, A123 battery specifications, and working with A123 batteries:
Overview of A123’s technology:
http://www.batteryspace.com/prod-specs/6610_1.pdf
ANR26650M1-B Brochure/Specs:
http://www.batteryspace.com/prod-specs/6610.pdf
APR18650M1-A Brochure/Specs:
http://www.batteryspace.com/prod-specs/6612.pdf
Cylindrical Battery Pack Design Guide:
http://www.formula-hybrid.org/wp-content/uploads/A123-Pack-Design-Guide-for-Cylindrical-Cells.pdf
https://imgur.com/a/8UefF
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