On Friday, May 8, 2020 at 12:21:11 PM UTC-7, John Silverberg wrote:
Hi,

I'm hoping someone with experience with K2 batteries can help determine if mine are due for replacement. I have dual K2 batteries wired in parallel to supply avionics power. I have an LX9000, S8 and V8 varios, trig transponder, FLARM core, and becker com radio running off them. I'm not sure how old they are but they're at least 3 years old as this is my 3rd season with the ship. Yesterday, after a little over 5 hours I got a low battery warning with the batteries at 11.3 volts. I had all the above avionics on but did virtually no transmitting on the com, just listening. They were fully charged at takeoff.

I'm not sure if this normal endurance for these batteries or not, any advice would be appreciated.

Thanks,

John S.

I am not sure which K2 batteries you are using, but they are likely at the end of their life. I have all of the avionics you have, and am drawing 2 - 2.1 A at a higher voltage (meaning you are drawing even more). I put in a Bioenno 20AH lithium battery and it can handle an 8 hr flight. You should only be discharging an SLA battery no more than 50% of its capacity.

Tom