Battery blankets

What do you guys think of leaving a battery blanket on with the block heater in really cold tempatures? I have read you should have them on a timer? Will leaving it plugged in all night damage my battery?

 

-41

 

I use one and it makes a big difference. On a warmer Saturday (-5F) I plugged my truck in and kept track of the battery voltage each hour. When the truck was cold the battery was at 11.66v, after being plugged in for three hours it was at 12.1v. A trickle charger would also work to keep the battery warm and charged.

 

One of those things it can`t hurt !

But then 200 yards of extension cords can be a pain

Then the days when your far from electric for days

 

lol it’s mostly overnight I’m concerned, where I can park nice and close to the plugs on the house.

At work isn’t so bad I could run a cord but haven’t needed to usually once it’s warm and the sun shining on it it’s fine. Remote start it for a few minutes before I go if it’s below -20

 

Battery blankets i use usualy have a thermostat in them. It makes a huge difference. Along with a battery tender n a coolant circulating heater.

 

Last year at -30 I used a laser thermometer after two hours the top of the battery was around 0 degrees. Perfect for good cranking. Combined with the basic block heater it turned over like a warm fall day.

Without being plugged in at -30 is not a good feeling if it turns over at all.

 

I've left mine plugged in almost constantly for the last 3 weeks. It's been an unrelenting frozen hellscape here for almost a month and the blanket makes a huge difference maintaining cranking juice. Unlike a block heater I think these almost need to be left on all night. At only 80 watts it takes a long time to raise temps when it's colder than a hooker's heart. But every morning there's a small patch of hood above the battery with no frost on it so I know it's still working. Lengths of velcro strapping also a lot better job at keeping the blanket snug to the battery than the shitty ties usually included. Easier to pull off in the summer too.

Checking your block heater for resistance is another thing to do in this cold. Our 400 watt BH should read around 35 ohms. After a hard start the other morning I checked mine and had 0 ohms. Traced it to the cord, snipped off the plug which actually looked perfectly fine, replaced it and that was it.

 

Yeah it’s sure not much power consumption and keeps that battery in good condition. I plugged in the wrap inside before installing and it didn’t take long to be very warm. Warms up the battery very effectively in about 2 hours I think.

 

I have at times taken the battery in side to keep it room temperature, car started right up with a warm battery. I only drove to town about once a week though. Temps were -50F at night for about three weeks.