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48VDC Heater mats

B

Blue Devil

New Member
Joined
Mar 20, 2022
Messages
4
Location
Northwest Ohio, USA
Does anybody know of a 48 volt DC heater mat that I can keep my batteries warm with?

I have a DIY system in a enclosed trailer and at the beginning of last winter I started getting low temperature disconnect for charging. To protect my batteries and my investment I decommissioned my system and removed the batteries and stored them in the house over the winter. Since spring is going to be arriving very shortly I want to get the batteries put back in. With doing that I would like to put some heater mats on the batteries before I install them that way I do not have the same issue next winter.

Of all of the heater mats that I have found so far they are only 12 or 24 volt DC or 120 volt AC. I really do not want to use 120 volt AC ones, I just think they are inefficient with all the conversion losses. Also if I was to use 12 or 24 volt ones how much, if any, loss would I have in the voltage step down to run them from my 48 volt system? Is it possible to series connect either the 12 volt ones or the 24 volt ones to work on my native 48 volt system?

I know I would have to have some sort of temperature controller to turn them on or off, but that would be the next step after I find what heaters I want or need to use.
 
Blue Devil said:
Is it possible to series connect either the 12 volt ones or the 24 volt ones to work on my native 48 volt system?
Click to expand...
It's not only possible, but likely to be your best solution. There are tons of 12VDC heater pads, and connecting four in series will allow you to spread them around a bit to cover more area. I experimented with several for my 24V 8S pack, and found that a couple of the little 12V 12W pads were perfect.

I can give you a link to the pads I used (if they are still available) if you want. You can also look at the build thread for my heated, insulated battery box (I'll need to find it first though).
 
Blue Devil said:
Does anybody know of a 48 volt DC heater mat that I can keep my batteries warm with?

I have a DIY system in a enclosed trailer and at the beginning of last winter I started getting low temperature disconnect for charging. To protect my batteries and my investment I decommissioned my system and removed the batteries and stored them in the house over the winter. Since spring is going to be arriving very shortly I want to get the batteries put back in. With doing that I would like to put some heater mats on the batteries before I install them that way I do not have the same issue next winter.

Of all of the heater mats that I have found so far they are only 12 or 24 volt DC or 120 volt AC. I really do not want to use 120 volt AC ones, I just think they are inefficient with all the conversion losses. Also if I was to use 12 or 24 volt ones how much, if any, loss would I have in the voltage step down to run them from my 48 volt system? Is it possible to series connect either the 12 volt ones or the 24 volt ones to work on my native 48 volt system?

I know I would have to have some sort of temperature controller to turn them on or off, but that would be the next step after I find what heaters I want or need to use.
Click to expand...

Actually, you'll need to consider the whole package.

Whilst series connecting the pads will help with the 48V issue, most of the temp. controllers are 12V.

I use these:

Amazon.com: LM YN DC 12V Digital Thermostat Module -58℉ to 257℉ Fahrenheit Temp Display Temperature Controller Board With 20A Relay Waterproof Sensor Probe Dual LED Display Red Blue: Home Improvement

Amazon.com: LM YN DC 12V Digital Thermostat Module -58℉ to 257℉ Fahrenheit Temp Display Temperature Controller Board With 20A Relay Waterproof Sensor Probe Dual LED Display Red Blue: Home Improvement
www.amazon.com

Cost effective and a perfect fit for what needs to be done.

My opinion is to just get the 48 to 12 conversion out of the way and run everything off 12. Lots of inexpensive DC-DC converters for that.

The heat pads I have used are:

 
The thermostat can run off a really cheap buck converter, then you can still run the heating pads (which will consume way more current) directly off 48V.

However, if there are lots of other 12V loads the OP wants to power (he didn't mention any) I suppose he can do what you have suggested.
 
Horsefly said:
It's not only possible, but likely to be your best solution. There are tons of 12VDC heater pads, and connecting four in series will allow you to spread them around a bit to cover more area. I experimented with several for my 24V 8S pack, and found that a couple of the little 12V 12W pads were perfect.

I can give you a link to the pads I used (if they are still available) if you want. You can also look at the build thread for my heated, insulated battery box (I'll need to find it first though).
Click to expand...
Thanks Horsefly. I have found your thread and will read it after work today.
 
v_green57 said:
Actually, you'll need to consider the whole package.

Whilst series connecting the pads will help with the 48V issue, most of the temp. controllers are 12V.

I use these:

Amazon.com: LM YN DC 12V Digital Thermostat Module -58℉ to 257℉ Fahrenheit Temp Display Temperature Controller Board With 20A Relay Waterproof Sensor Probe Dual LED Display Red Blue: Home Improvement

Amazon.com: LM YN DC 12V Digital Thermostat Module -58℉ to 257℉ Fahrenheit Temp Display Temperature Controller Board With 20A Relay Waterproof Sensor Probe Dual LED Display Red Blue: Home Improvement
www.amazon.com

Cost effective and a perfect fit for what needs to be done.

My opinion is to just get the 48 to 12 conversion out of the way and run everything off 12. Lots of inexpensive DC-DC converters for that.

The heat pads I have used are:

Click to expand...

Thanks v_green57. I have not thought about finding a 48vdc controller yet. If I'm thinking correctly, could I use a 12v or 24v controller to control a compatable relay to control 48v.
 
Horsefly said:
The thermostat can run off a really cheap buck converter, then you can still run the heating pads (which will consume way more current) directly off 48V.

However, if there are lots of other 12V loads the OP wants to power (he didn't mention any) I suppose he can do what you have suggested.
Click to expand...
Thats what I was thinking of doing if I had to use a lower voltage unit to control the heating pads. I will have a 48v-12v converter to operate 12v lights and the powered awning on the trailer. I do not have one yet, just haven't sized it yet. Currently it is a 12v deep cycle battery on the trailer that charges off the vehicle while towing.
 
batteryhookup.com

24/48v 150w Battery Heating Pad Hi-Heat - Made in USA

These heating pads were recovered from our 24v Super Beast batteries. This is made specifically for lithium batteries. All you need is a relay to trigger this on and off when temperatures reach below freezing. These are usually very expensive online but here just $6. They were all removed in...
batteryhookup.com batteryhookup.com
 
42OhmsPA said:
batteryhookup.com

24/48v 150w Battery Heating Pad Hi-Heat - Made in USA

These heating pads were recovered from our 24v Super Beast batteries. This is made specifically for lithium batteries. All you need is a relay to trigger this on and off when temperatures reach below freezing. These are usually very expensive online but here just $6. They were all removed in...
batteryhookup.com batteryhookup.com
Click to expand...
Well, I think there are lots of ways to do it. My 24W (2 x 12W) is plenty for my 8S 24V pack. You don't want to heat them fast, you want to heat them slowly. It allows the heat to be absorbed through the whole battery pack before cooking the side that is closest to the heating pad. But maybe 150W is still OK. I personally would go for something with fewer watts.
 
Here is a thought…

You may want something like a Victron Battery Protect (BP-65). Something to kill power to the heaters if the voltage gets too low at say 12.5v times 4 = 50v.

You don’t want the heaters to drop the batteries to empty (bms cutout) then the bms’s trickle draw finish killing the battery. It would be far better to leave plenty of power in the battery for the bms and have the low-temp cutoff stop charging.
 
Rocketman said:
You may want something like a Victron Battery Protect (BP-65). Something to kill power to the heaters if the voltage gets too low at say 12.5v times 4 = 50v.
Click to expand...
Yep, that's exactly what I did. It's a bit overkill, but it is s sweet little device and keeps the battery from going dead.
 
I've used two 24v 40w truck mirror demisters, these are wired in series and stuck to the bottom of a 10mm thick aluminium plate that the 16 cells sit on. I've not built the rest of the heater system yet, but the intention is to use a Victron 12v power supply, through the Cerbo relays to control a solid state relay, which then supplies power to the heater from my 48v distribution system.
 
Anybody run a 48V heating pad setup that is relay controlled with a Victron Cerbo or other device?
 
@AlaskanNoob any decisions here? I only found 1 or 2 48V pads in my search, and they were 300W which seem excessive. I know I could series the 12V ones together, but I am thinking of using one of the many 12V pads with this buck converter (UR certified) between it and my battery, and then using a relay on my VenusOS pi to turn it on/off based on temp if the pad doesn't have its own temperature switch:

Note: I edited the URL below, I originally posted the wrong model

trcelectronics.com

DDR-120C-12

Shop for the Mean Well DDR-120C-12 DC/DC converter from TRC. We offer unbeatable discounts and ship same day. Buy DDR-120C-12 with confidence and get fast shipping!
trcelectronics.com trcelectronics.com
 
cdsolar said:
@AlaskanNoob any decisions here? I only found 1 or 2 48V pads in my search, and they were 300W which seem excessive. I know I could series the 12V ones together, but I am thinking of using one of the many 12V pads with this buck converter (UR certified) between it and my battery, and then using a relay on my VenusOS pi to turn it on/off based on temp if the pad doesn't have its own temperature switch:

trcelectronics.com

DDR-120D-12

Shop for the Mean Well DDR-120D-12 DC/DC converter from TRC. We offer unbeatable discounts and ship same day. Buy DDR-120D-12 with confidence and get fast shipping!
trcelectronics.com trcelectronics.com
Click to expand...

We got some off Amazon but I haven't wired them up yet. I'm going to be moving all the batteries down into the root cellar and building a super insulated new rack for them, then I'll install 4 of these 12V mats on some metal under the 8 batteries. We got an Orion to step down our 48V to a 12V bus bar to power the mats and other things.

Plan is to use Node Red and some USB relay extension on the Cerbo GX to turn them on if and when needed. But I think there is a decent chance I won't need them once they're in the cellar even at -5F outside.
 
cdsolar said:
@AlaskanNoob any decisions here? I only found 1 or 2 48V pads in my search, and they were 300W which seem excessive. I know I could series the 12V ones together, but I am thinking of using one of the many 12V pads with this buck converter (UR certified) between it and my battery, and then using a relay on my VenusOS pi to turn it on/off based on temp if the pad doesn't have its own temperature switch:

Note: I edited the URL below, I originally posted the wrong model

trcelectronics.com

DDR-120C-12

Shop for the Mean Well DDR-120C-12 DC/DC converter from TRC. We offer unbeatable discounts and ship same day. Buy DDR-120C-12 with confidence and get fast shipping!
trcelectronics.com trcelectronics.com
Click to expand...

Seems like we have both come to the same relative plan. Do you use your Pi to control everything, or is that in addition to a Venus GX device (like a Cerbo)?
 
I was going to use the heat control on my 24V JK BMS batteries with the small 12V pads, but just decided it's cheaper and simpler to heat the whole battery cabinet with an Amazon seedling heated mat with temperature probe and thermostat, yeah it's 27W AC but should do the job. Now I've got it it's got warmer outside!

IMG_20240201_164915_794.jpg
 
AlaskanNoob said:
Seems like we have both come to the same relative plan. Do you use your Pi to control everything, or is that in addition to a Venus GX device (like a Cerbo)?
Click to expand...
I use a Raspberry Pi running VenusOS to monitor my inverter, charge controller and battery. The first two are Victron and the battery is EG4 LLv2 which can talk Victron Protocol. I am a Linux guy by trade so doing it this way instead of Cerbo gives me a bit more flexibility, but it is the same OS as a Cerbo.

I only run cameras, lights, and occasional use AC in a barn (with PtP WiFi back to house to watch animals) so my setup is small. If your handle indicates where you live, it is a lot colder there than here, so while I'll need the pads for around 2 months, you'll need them longer
 
AlaskanNoob said:
Interesting. Do you set the temperature you want, and it then opens/closes when it gets 5C off that temp?
Click to expand...
these generally have a set temperature and a set threshold, you also need to make sure you get NC [normally closed] for colder than room temp and a NO [normally open] for warmer than room temp. that 5C NC will close around 0C and open when it is warmer than 5C, if you wanted the batteries to be warmer get a 10C or 15C

i'm fairly certain that is how the NC and NO work but i would double check in case my lexdysia is acting up.
 
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