For the first time I've seen the battery heater kick on. Here some pics and info I learned in case people were curious. When I first started the charge, I noticed it was drawing 8 Amps & 120v, display says it was doing battery heating. After about ~15-20mins it switched to normal charging and now drawing 12 amps. Seems to match up with the ~1000 watt model at (page 76).