Heating element question

[Doc Harley]

Cordless drill battery can be a handy power source for tests like this, just don’t leave it hooked up for prolonged periods of time if it’s an 18 or 20v unit.

Why didn't I think of that? Lol....

Well I suppose it comes down to this. After further testing I found my particular heating element gained approximately 23° f. From appx 65° f to 88° f after 5mins tied to battery.
I'm not sure if 23° increase is what the manufacturer is expecting but I will say this. When riding at 9° or lower the contents of the bag is still below freezing.
Does make a whole lotta sense?!?!

 

[Doc Harley]

There should not be any issue with polarity in your wiring so yes, it looks like your element may be bad. I should have asked however, how long are you waiting for it to heat up? With only 9v and depending on the condition of the battery it may take awhile, especially if the battery is older. ..minutes anyhow. I duplicated your setup using a nogo genius battery charger running in 13v supply mode. As you can see, the thermal pad pulled the charger down to 6.52v but quickly heated the pad up to 128' F.

View attachment 169566

Earthling, do you have a part# for that particular pad that you tested?

 

[earthling]

Looking at your heating pad, its a pretty large area to heat for such a low wattage. I suspect that this is more of a 'warming' pad as opposed to a heating pad. The orange-y heating pads get very-very hot. When I look at all the varieties of orange silicon heating pads out there you can see that wattage = area. Larger wattage pads are larger in size and all of them have a relationship of wattage to area that ends up in a lot smaller size than what you have.

But.. it depends on what you want the pad to do. In my case I want it to heat up a larger chunk of metal plate and through that heat a larger chunk of metal that is the case of a small tablet. I would have used a smaller pad as I think I really need like 40w of power but have not stopped to actually figure it out yet and access to these heating pads is limited in Canuckistan.

No, I don't have a part number because it was just some random pad that was available through amazon.ca prime. Convenience FTW.

This is what I bought but don't buy that one, its way overkill I think for what you are looking for and draws 10 amps.

I am going to do some more research and maybe do the math to figure out what I really need, first and foremost however I need a better place to buy the heating elements.

 

[Doc Harley]

Looking at your heating pad, its a pretty large area to heat for such a low wattage. I suspect that this is more of a 'warming' pad as opposed to a heating pad. The orange-y heating pads get very-very hot. When I look at all the varieties of orange silicon heating pads out there you can see that wattage = area. Larger wattage pads are larger in size and all of them have a relationship of wattage to area that ends up in a lot smaller size than what you have.

But.. it depends on what you want the pad to do. In my case I want it to heat up a larger chunk of metal plate and through that heat a larger chunk of metal that is the case of a small tablet. I would have used a smaller pad as I think I really need like 40w of power but have not stopped to actually figure it out yet and access to these heating pads is limited in Canuckistan.

No, I don't have a part number because it was just some random pad that was available through amazon.ca prime. Convenience FTW.

This is what I bought but don't buy that one, its way overkill I think for what you are looking for and draws 10 amps.

I am going to do some more research and maybe do the math to figure out what I really need, first and foremost however I need a better place to buy the heating elements.

Haha....yes, that one is way too much.
I appreciate your time and working with me on this project. Very thankful!
Your assessment of my heating element is, more than likely, spot on. Glad I didn't make the mistake of replacement. $25+/-only to be further disappointed.
My short term solution will be a box of hand warmers, as I did this last year.
Until I find an equitable solution.

Planning two long excursions, one in the UP and another in Ontario, Canada.

Ty, Earthling.....peace

 

[earthling]

Well, I more or less committed to solving this problem for my buddy for this season so I will post my findings if it seems worthwhile.

 

[earthling]

New heating pad I ordered was 12v 15w and I have it controlled with a 12v thermostat. It is working well on the bench so far, 1amp draw as expected. Trying buck convertors next.

 

[earthling]

Using the buck convertor and limiting power to 6v drops current use to .25 amp. The heating element holds a nice 100 degrees but that is inside a room at an ambient temperature of 71f. Its too warm outside right now for real testing but I think a high-low switch with the buck convertors is the way to go. Now to build a few harnesses and start designing the tablet holder(s). @jtmetal I will stop posting here in your thread, if you want to pick up your project later in the season or next season just PM and I will share whatever details I come up with for parts and wiring harness.

 

[Doc Harley]

Using the buck convertor and limiting power to 6v drops current use to .25 amp. The heating element holds a nice 100 degrees but that is inside a room at an ambient temperature of 71f. Its too warm outside right now for real testing but I think a high-low switch with the buck convertors is the way to go. Now to build a few harnesses and start designing the tablet holder(s). @jtmetal I will stop posting here in your thread, if you want to pick up your project later in the season or next season just PM and I will share whatever details I come up with for parts and wiring harness.

View attachment 169764

Right on....nice work, Earthing...in order to make it marketable you'd need to have a simple plug & play set up that works with RCA input.
I was just saying....lol. Lots of riders complain about the lack of heat these warmers provide.