I got the West Mountain Radio tester and ran my three K2 Energy 9.6 AH (two years old) One tested at 8.7 AH, the next at 8.5 AH, and the final one 7.3 AH. They are all charged using a dedicated LIFEPO4 charger. Not sure why the one should have so much less capacity. I will be giving K2 a call.

David
ASG29E BV