It started up OK at -19F on Feb 4, at Togwotee Lodge Wy.I used a Shorai LFX27A3-BS12 rated at 405 CCA. Fits in stock location on my 2020 MC M-8000. It includes shims to snug up the fit. Only used a few. The + terminal is on the PTO side which matches the stock battery. About 3.5 lbs. So far so good however haven't been in negative temps yet.