If you are contemplating an EarthX battery, spend 15 minutes acquainting yourself with the EarthX charging requirements. On their website is a chart of battery chargers that are acceptable for charging their batteries other than the fully automatic Optimate chargers they recommend and sell.
https://earthxbatteries.com/our-batt...ttery-charging
I purchased the Optimate from EarthX with the continuous power option and have used it several times for hours at a time while upgrading and programing avionics.
I also have their jump pack which came in handy the two times I’ve left my Garmin Aera 500 on all night and ran the battery down.
BTW Steve, I have the EXT-680 for my 912uls and it is mounted in Kitfox Aircraft’s firewall battery box. The “C” version has same cranking specs in a slightly smaller case and slightly less weight.
B7A19542-F1EE-48D7-85FA-5A59FD490070.jpg