Advice Running an Electric Blanket from a Battery

Hi all, More and more, I'm digging cold weather camping. You get the whole place to yourself, check-in and check-out times are rare, and the day time temps might be totally manageable. You just have to handle night time lows.

Colorado has plenty of non-developed places to camp. Free camping is great. But, you do have to take that night-time insulation seriously.

If I go to a state park, I can pay $35 per night (our state parks are pricey) for a reliable electric site and run an electric blanket. But that's sort of steep when compared to the alternate cost of free.

So, I'm looking to bridge that gap. If I ran an ordinary electric blanket overnight in my tent from a battery, plus the sleeping bag, pad and layers, then the free winter time camping is all mine.

Does anyone have experience with this? How much battery capacity would I need for one or two night runs? Can you recommend any good battery brands? I have heard of Goal Zero and Jackery.