I picked up a similar unit for $30.00. I tried it on the cigarette outlet and it was getting pretty warm after about 15 minutes. I'm pretty sure my power supplies won't handle any more than the 2 chargers each they're already running so I'll have to add another smaller power supply for the heater. Hope to try it at the field this weekend at the field if it doesn't rain. It's definitely cooler out than it was at Quincy so I'll need to do something. I thought Quincy was more like low to mid 60's. Have you taped off your air inlets or are you relying on just pre-warming the batts?
Verne
ORIGINAL: rm
Tried it out this morning. Air temp was 60-64F. Highest inside temp measured was 113F, that was close to 1.5hrs. Packs were coming out at about 85 -103, depending on how long they were in there, last one, 103, was prob close to 1.5 hours. Had good power from the outset. Handy to carry them in also, worth the $5. I would guess it was in the mid to upper 50's the morning we had problems?