Diesel Heater Muffler/Battery Question


I have two questions for people here who use a diesel heater (I’ve got a Planar heater but this really pertains to any portable diesel heater).

  1. Do you use a muffler? Mine has a somewhat loud exhaust so I’m wondering if a muffler even makes any sort of significant difference.

  2. What do you do with your deep cycle battery when it’s running the heater? Do you put it in a box? Do you leave it in your truck bed? Do you leave it open to the elements all winter?

I’m new to diesel heaters so I’m just wondering what the best practices are, mainly.

Thank you so much!

It makes a MASSIVE difference. It won’t change the pump clicking, but definitely will make the heater quieter on the exhaust.

My lithium batter is installed in the box of the truck as the heater is not the only thing it powers. Before getting a Planar gasoline heater myself, my diesel heater was installed in a box and exposed to the elements.

You can check out my two iterations in my build page here:

I haven’t fully field tested the Autotherm (now Planar) yet but bench tests have been positive.

Hope that helps. There are links in my build as well to details on the diesel heater guru on YouTube. John McK 47 , dudes a legend and an Ausi so it’s a good watch :smiley:

Amazing, thank you! I’ll check out that link. You used a lithium battery with your heater? When I was talking to Planar they said that I should be using a Marine Deep Cycle Lead Acid battery. I’d love to switch to lithium - I guess it doesn’t have any issued with the amperage? I think mine draws about 10 amps and then drops to around 2-3 after startup.

In any case, thank you so much and I’ll check out the link now. Much appreciated!

  1. Yes, use the muffler as it makes a big difference. I got this one here and it helped out a lot

  2. I will either run it off my Eco Flow Delta 2 or with alligator clamps directly to my secondary AGM battery. They do pull a lot on start up so I do start my truck for 10-15 mins on start on and to recharge slightly with the initial power draw.

That’s the first I had ever heard of that with regards to battery type. That’s common for the amp draw, and it also does the same thing when it turns off to ensure it burns off any carbon and prevents fouling of the glow plug. I’ve been running a 100aH Lithium for 2 winters going on three. No problem. I switched because a deep cycle doesn’t cut the mustard for me, not to mention the additional weight. You only get 50% of the usage out of a Deep cycle if you want to not shorten the life of the battery. Also, they perform like shit in the cold. So depending where you’re from, I strongly discourage the use of those.

Depending on your build out, pay attention to the weight you’re adding to the truck. Every pound, including yourself, counts agains your GVW. Depending where you live, if it’s found during an accident that you are over weight. You can kiss your insurance coverage goodbye.

I will book end this with batteries, you’re going to find differing opinions. Having worked in telecommunications for 15 years. We use deep cycle batteries in our subs carrier cabinets. We HAVE to run either a heater, or at a minimum a heat pad. Otherwise you will loose performance from the battery DRASTICALLY. So, unless you want to be tasked with removing the unit from your truck when you’re not using it you have to keep it warm. That’s why they make heated lithium batteries (also so they can be kept above 0 for charging)

So it all really comes down to what the average temperature is where you live in the winter.

I do have a deep cycle in a box that I’ll sometimes use in one off uses. But my 1/2 ton with a build out pushes 700lbs of payload. So by using a lithium I shed about 30lbs or so on a 100AH battery. That means a lot more candy in the candy cubby.

Thank you for this information! I’m in Ontario Canada so it definitely gets pretty chilly up here in the winter. Since I already have a deep cycle lead acid maybe I’ll give that a go this year and switch to lithium next year to compare the two. I have a battery heater blanket as well so maybe that’ll help? Time will tell.

This is all great information though - thank you so much!

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Awesome thank you! I’ll check out that muffler.

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I grew up in Sudbury :wink: and coached Freestyle Skiing at Horseshoe resort before moving out west. I’m familiar with the cold there that’s for sure. I think you’ll be surprised with the heater I think the heated blanket will be overkill. But personally I use my -20 bag in the winter and generally shut the heater off at night to avoid having to deal with it messing up in the middle of the night.

I’ve had it overheat, I’ve run out of fuel, I’ve had it kill the battery (lead acid), all of which are unpleasant ways to wake up. I’m a light sleeper, and it’s not a good sound when you wake up to hearing it Puff itself off in shutdown (you’ll know the sound I’m talking about when you hear it)

I’m in a full size with a 5kW and it is the perfect size. My gasoline Planar is 4kW and I have no doubt it will be sufficient. The best thing is…I can dry my ski gear!!!