As part of my condition inspection, I would like to perform a battery endurance test on the internal batteries in my EF and EM. Only problem is, the units keep trying to power off every 5 minutes, even though at initial power-up I cancel the power-off message. Is there a way to keep these units powered on in my hangar (with no engine running, tach signal zero rpm)?

Or is there a better way to perform an internal battery endurance / capacity test? I don't want to find out that my internal battery endurance is only 6 minutes when I have an electrical failure in IMC!

Thanks.