Cold weather dwellers - do you use a battery warmer/blanket?

[James9100]

For those of you that get cold weather (I mean really cold, not just 20°F at the coldest) do you bother using a battery warmer/blanket?
I’m considering picking one up but not sure if it’s really needed. My TJ sits outside and does not get used regularly, it does have a block heater and new AGM battery.
Average temp right now is about -5°F/-15°C, I never start it in colder than -13°F/-25°C even if the block heater is plugged in.

So in temps of lets say 15°F/-10°C to -5°F/-20°C is a battery warmer really needed/that helpful or is just a block heater and good battery enough?
Keep in mind as I said it’s also not driven on the daily, if it was being started every morning could totally see the blanket being worth it.

 

[ColoJeep]

For those of you that get cold weather (I mean really cold, not just 20°F at the coldest) do you bother using a battery warmer/blanket?
I’m considering picking one up but not sure if it’s really needed. My TJ sits outside and does not get used regularly, it does have a block heater and new AGM battery.
Average temp right now is about -5°F/-15°C, I never start it in colder than -13°F/-25°C even if the block heater is plugged in.

So in temps of lets say 15°F/-10°C to -5°F/-20°C is a battery warmer really needed/that helpful or is just a block heater and good battery enough?
Keep in mind as I said it’s also not driven on the daily, if it was being started every morning could totally see the blanket being worth it.

For what it's worth I started our 99 4.0 Tj and 04 Tacoma 3.4 this morning at 11F without anything . No issues with either. Both have NAPA Legend AGM's and Mobil 1 oil .

 

[James9100]

For what it's worth I started our 99 4.0 Tj and 04 Tacoma 3.4 this morning at 11F without anything . No issues with either. Both have NAPA Legend AGM's and Mobil 1 oil .

Oh of course it will start, I’ve started it in plenty cold (with the block heater plugged in). Just cranks a little slower due to the battery cranking amps dropping in the cold.
A guess another way to word my question would be, is a battery warmer really only worth it if you’re starting it up in colder than -15°F(ish)?

 

[ColoJeep]

A guess another way to word my question would be, is a battery warmer really only worth it if you’re starting it up in colder than -15°F(ish)?

Yes.

 

[ChadH]

Usually I get a good solid month of -20 to -30 F. This winter so far has been unusually warm. That said, I never bothered with a battery heater. Just keep it on a high quality charger that will function at those temps. Something like a Victron or CTEK. And not just a 5a charger, usually a 15a minimum. Also having a good quality AGM, not the cheapest option, is helpful. So far these methods have not let me down. Jeeps and the tractor stay plugged in to the charger when not driving, usually they get unplugged before starting and fire right up ever time.

If anything I would explore an oil heat pad that can stick to the bottom of the oil pan, or a block heater. Personally though if I were to look into the heater option, at least for my temps, I would just go for broke and install a wabesto coolant heater that can run off the gas tank to pre-heat the coolant and part of the block.

 

[DuckNut]

When I lived up in the frozen tundra, when it got really cold, I just left my vehicles running. Oil gets like jelly and diesel fuel turns from liquid to solid. Several times I had to build a BBQ under the fuel tank.

In your case, your overthinking it. If you parked it for the winter, leave it parked.

 

[Steel City 06]

Not really necessary for those temperatures depending on the condition of the battery.

A good alternative might be an onboard battery float charger wired to operate with your block heater. That will not only make starting easier (float charge plus a tiny amount of battery heating) but also help extend its life.

 

[MikekiM]

Not really necessary for those temperatures depending on the condition of the battery.

A good alternative might be an onboard battery float charger wired to operate with your block heater. That will not only make starting easier (float charge plus a tiny amount of battery heating) but also help extend its life.

Tell me more about the battery float charger thing... please.

 

[James9100]

Tell me more about the battery float charger thing... please.

Just an onboard battery maintainer.

Not really necessary for those temperatures depending on the condition of the battery.

Basically a brand new AGM, made by East Penn.

In your case, your overthinking it. If you parked it for the winter, leave it parked.

Not 100% parked for the winter, just driven a time or two on the weekend as I have a company truck.

 

[sab]

When I lived in Roseau, MN, temps in the -20°F to -30°F happened every year for long periods. The coldest I experienced was -54°F. All of my vehicles had either block heaters and/or oil pan heaters (a silicone pad glued to the oil pan to keep the oil warm.) None of them had battery warmers. I never met anyone up there who used a battery warmer. As long as a lead-acid battery is kept charged, it can withstand very cold temperatures. It's only when it gets discharged a bit that temperature comes into play.

 

[ColoJeep]

When I lived in Roseau, MN, temps in the -20°F to -30°F happened every year for long periods. The coldest I experienced was -54°F. All of my vehicles had either block heaters and/or oil pan heaters (a silicone pad glued to the oil pan to keep the oil warm.) None of them had battery warmers. I never met anyone up there who used a battery warmer. As long as a lead-acid battery is kept charged, it can withstand very cold temperatures. It's only when it gets discharged a bit that temperature comes into play.

The only thing I've seen a battery warmer on was a new Cummins Onan standby generator . It was in a mission critical building application.

 

[DJ_w_TJ]

I live in Manitoba Canada where it gets very cold (-14°F right now!), and I've never used a battery warmer. For peace of mind, maybe get one of those little booster packs instead. If your battery is not too old, you shouldn't ever need more than that.

 

[squirrelmaster]

When I lived in the Minnesota / Wisconsin area I used a block heater, oil pan heater, and fuel tank heaters (on my diesel trucks), but always a good quality AGM battery. I also had a trickle charger on my diesel trucks for those -60 degF days, as it can help keep the battery topped up but also to keep the battery a bit warmer to increase cold cranking amps. I didn't add the trickle charger to my Jeeps, but the block heater and oil pan heaters kept the oil viscosity down enough that it never felt warranted (unlike the high-compression diesels).

 

[Limestone]

Usually I get a good solid month of -20 to -30 F. This winter so far has been unusually warm. That said, I never bothered with a battery heater. Just keep it on a high quality charger that will function at those temps. Something like a Victron or CTEK. And not just a 5a charger, usually a 15a minimum. Also having a good quality AGM, not the cheapest option, is helpful. So far these methods have not let me down. Jeeps and the tractor stay plugged in to the charger when not driving, usually they get unplugged before starting and fire right up ever time.

If anything I would explore an oil heat pad that can stick to the bottom of the oil pan, or a block heater. Personally though if I were to look into the heater option, at least for my temps, I would just go for broke and install a wabesto coolant heater that can run off the gas tank to pre-heat the coolant and part of the block.

I agree. From original post, it sounds like it sits for some period of time and battery drain would be primary concern. So if taking the battery out/in while not in use is too inconvenient, a trickle charger is the best bet.

I DD my TJ. I'm thinking about a stick on warmer for the oil pan to keep the oil a little thinner and if it happens to get really really cold for a few days I can drag out my trickle charger and plug that in. If it struggles after that, I'd reconsider my need to leave the house tbh.

 

[NDSpeed]

https://www.amazon.com/Schumacher-S...-Maintainer/dp/B07894CFCR/?tag=wranglerorg-20

Every vehicle i have, one of these has been installed.

this year alone i’ve put 395 miles on the F-350. so it helps every month or so i’ll plug this in for a few hours. but in winter. when it hit 20F or lower i would plug it in more often.

the heat pad just boils the acid. which then ruins the blanket. a tender will warm it up from the inside.

with my Jeep i put a space heater in the engine bay and then put a foil blanket over the hood. but that’s because my glow plugs were not working. i also didn’t drive on the ice with the LSD. made it too sketchy.

the colder it gets to more you have to do. the guys i know in the North Slope just leave the vehicles running all winter long. they bring them in to the garage to do the oil changes. that’s the only time those trucks get shut off

 

[NDSpeed]

Remember with trickle chargers you don’t want to off gas the electrolytes.

so don’t over use them.

 

[squirrelmaster]

Remember with trickle chargers you don’t want to off gas the electrolytes.

so don’t over use them.

This is a fair point. I should note that I used a floating point trickle charger on mine, so the charger only operated below a certain voltage threshold (which generally happened when it got stupidly cold).

 

[NDSpeed]

https://www.amazon.com/5in-Engine-Silicone-Heater-Self-Adhesive/dp/B0CL7876PM/?tag=wranglerorg-20

Heating pads for reference

again with these it needs to be really Cold. you don’t want to cook your oil living in Phoenix and it got down to +20F

 

[ChadH]

Tell me more about the battery float charger thing... please.

I have the CTEK on my tractor.

I have the second link mounted permanently in the Gladiator, it will eventually go on the LJ. The TJ currently has the third link mounted under the hood and will eventually receive the same as the LJ. They are aswesome as you can access them via bluetooth app to see the charging history and graphs as well as change adjustments like the charge voltage.

https://www.amazon.com/CTEK-56-353-12-Volt-Battery-Charger/dp/B000FRLO9Y/?tag=wranglerorg-20

https://www.amazon.com/Victron-Energy-12-Volt-Battery-Bluetooth/dp/B07TMRJQTH/?tag=wranglerorg-20

https://www.amazon.com/Victron-Energy-12-Volt-Battery-Bluetooth/dp/B07DWJD84N/?tag=wranglerorg-20

 

[JEEPSTEVENANAIMO]

Oh of course it will start, I’ve started it in plenty cold (with the block heater plugged in). Just cranks a little slower due to the battery cranking amps dropping in the cold.
A guess another way to word my question would be, is a battery warmer really only worth it if you’re starting it up in colder than -15°F(ish)?

When i was on the farm in 7persons alberta (basically saskatchewan ) we just put a 100watt bulb in a trouble light holder and left it under the hood. kept it warm and toasty. same thing we used under the mobile home as well to stop pipes from freezing. its cheap and works. now finding a 100watt bulb that could be a different problem. thankfully i left where the wind trys to eat my face for the warmth of the ocean.