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Discussion Starter #1
I wanted to buy a heated vest and since I am so bored with the Covid-19 lockdown, I said to my self BUILD IT!!

I searched what is the thinnest wire I have on hand and it is from a single twisted pair from a Cat5e Ethernet Cable.
I untwisted one pair, straightened with a screwdriver and fabricated a mat with adhesive tape on both side.

Once finished, I applied 13.5V to simulate the voltage from the bike when running.
I gave it 5.7A and it dissipated around 40 degrees C.
I have no idea how much amps the alternator can supply, but it is to be researched.
I think this is too much amps draw from the bike.

Next I tried a 20V max Dewalt battery.
I gave it 3.6A and it dissipated around 43 degrees C.
Which means a 1.5Ah battery wouldn't last more than 30 minutes.

I need a thinner wire for this work or I guess it is better if just I buy a heated vest from Amazon.
Either way, I had fun with that project.

Setup

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13.5V (Simulate Voltage From R9T Battery)

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18V (Dewalt)

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I wanted to buy a heated vest and since I am so bored with the Covid-19 lockdown, I said to my self BUILD IT!!

I searched what is the thinnest wire I have on hand and it is from a single twisted pair from a Cat5e Ethernet Cable.
I untwisted one pair, straightened with a screwdriver and fabricated a mat with adhesive tape on both side.

Once finished, I applied 13.5V to simulate the voltage from the bike when running.
I gave it 5.7A and it dissipated around 40 degrees C.
I have no idea how much amps the alternator can supply, but it is to be researched.
I think this is too much amps draw from the bike.

Next I tried a 20V max Dewalt battery.
I gave it 3.6A and it dissipated around 43 degrees C.
Which means a 1.5Ah battery wouldn't last more than 30 minutes.

I need a thinner wire for this work or I guess it is better if just I buy a heated vest from Amazon.
Wow what a great way to spend your time during this flu explosion. I’m the same kind of DYI’er. What you said about the alternator is a very important observation. The load your going to put on it is considerable. My situation is a bit different. When I tour I’m going to pull a small cargo trailer so I’m testing the idea of running a second alternator and battery set up in the trailer powered by the trailer wheel. It’s a single wheel set up and I’ll use an alternator from an automobile and a lithium bike battery. I can survive riding cold if the trailer system fails but if I fry the alternator the bike is dead, can’t have that. As long as you are confident in your build and don’t fry the system .... go for it. I’ll be anxious to hear about your progress. I’m going with factory made garments. I’m sure the research they have done is extensive and to DIY seems like re-inventing the wheel. Good luck my friend. Blitz
 

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Discussion Starter #3
Here are my observations:

  • I need to buy some heating pads. What I made is really not efficient.
  • I looked online and the vast majority of heating pads are 5V made in Cheena. I think you can go up to 12V on those pads but it needs to be tested first.
  • If using a power bank 5V, you will be limited by how much amp you can draw from the batteries. The best case scenario that I saw was 18W power draw. Which means 3.6 Amps. This could work but the battery bank is expensive.
  • I can go with the Dewalt 18V route, these will work, they are high output battery. With a small PWM controller attached to the Dewalt these would work fantastic.
  • What I really want to do is heat the seat and heat a vest connected to the 12V battery of the bike. The vest would connect to a USB plug somewhere on the bike. And yes you are right, it all depends on the available power of the alternator.
  • Last year I removed my OEM headlamp bulb which is 55W and replaced it with an LED one. I need to see how much power I saved...I am guessing around 20-25W.
  • On the other BMW forum, some people are changing the alternator for a 60A from 40A...however I think ours is already 60A.
  • I need to think about it...
 

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Here are my observations:

  • I need to buy some heating pads. What I made is really not efficient.
  • I looked online and the vast majority of heating pads are 5V made in Cheena. I think you can go up to 12V on those pads but it needs to be tested first.
  • If using a power bank 5V, you will be limited by how much amp you can draw from the batteries. The best case scenario that I saw was 18W power draw. Which means 3.6 Amps. This could work but the battery bank is expensive.
  • I can go with the Dewalt 18V route, these will work, they are high output battery. With a small PWM controller attached to the Dewalt these would work fantastic.
  • What I really want to do is heat the seat and heat a vest connected to the 12V battery of the bike. The vest would connect to a USB plug somewhere on the bike. And yes you are right, it all depends on the available power of the alternator.
  • Last year I removed my OEM headlamp bulb which is 55W and replaced it with an LED one. I need to see how much power I saved...I am guessing around 20-25W.
  • On the other BMW forum, some people are changing the alternator for a 60A from 40A...however I think ours is already 60A.
  • I need to think about it...
That’s interesting about the LED headlamp, i hadn’t considered that angle. That’s good ! On a different bike a few years ago I went so far as to tightly wrap the header pipe right up close to the head with 1/4” copper tube on top of heat sink silicon. It was about a 12” long coil of copper that hooked to rubber hoses. This system was filled with distilled water and a 12v pump. I made plastic pouches much like your adhesive sheet with wire. I used upholstery grade vinyl sheet and sonically welded a surreptitious path for the water much like your wire. It worked great until the water began to boil. I need to program an Arduino board to read the output temperature and control the flow rate by speeding up the pump to keep the water hot but under 212 so the system gets the heat but not the excessive pressure. I kept blowin the damn thing up. The excessive heat made the vinyl to soft and when you add the pressure to that .... well you get the picture. The problem was temperature control not concept. The idea worked well, a little to well. I need to determine the appropriate surface area, the number of winds of tubing and then thermostatically control the pump speed and I’m sure I can make it work. Who knows if I make it thru Covid19 and cancer and live to be 80 I might just get back to that one. I even investigated buying the water jacket liner manufactured for the astronauts space suits from a company in Florida. O Well. So many things to try and never enough time. Just seems like there’s an abundant heat source in those headers that’s going to waist. It’s used efficiently in automobiles, ...why not bikes? Can you imagine having a lined jump suit fully heated top to bottom? I can, I hate cold weather but I love to ride, I’ll find a way. I too am constantly re-inventing the wheel Manyakus. Have fun my friend...
explore the possibilities... there endless. ...Blitz
 

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Discussion Starter #6
FWIW, we’ve got watts to spare. I run without issue a heated jacket liner that uses up to 74 watts (6.2 amps). Admittedly, I almost never have it on high.
That is good to know!
Thanks for the info!
 

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Discussion Starter #7
That’s interesting about the LED headlamp, i hadn’t considered that angle. That’s good ! On a different bike a few years ago I went so far as to tightly wrap the header pipe right up close to the head with 1/4” copper tube on top of heat sink silicon. It was about a 12” long coil of copper that hooked to rubber hoses. This system was filled with distilled water and a 12v pump. I made plastic pouches much like your adhesive sheet with wire. I used upholstery grade vinyl sheet and sonically welded a surreptitious path for the water much like your wire. It worked great until the water began to boil. I need to program an Arduino board to read the output temperature and control the flow rate by speeding up the pump to keep the water hot but under 212 so the system gets the heat but not the excessive pressure. I kept blowin the damn thing up. The excessive heat made the vinyl to soft and when you add the pressure to that .... well you get the picture. The problem was temperature control not concept. The idea worked well, a little to well. I need to determine the appropriate surface area, the number of winds of tubing and then thermostatically control the pump speed and I’m sure I can make it work. Who knows if I make it thru Covid19 and cancer and live to be 80 I might just get back to that one. I even investigated buying the water jacket liner manufactured for the astronauts space suits from a company in Florida. O Well. So many things to try and never enough time. Just seems like there’s an abundant heat source in those headers that’s going to waist. It’s used efficiently in automobiles, ...why not bikes? Can you imagine having a lined jump suit fully heated top to bottom? I can, I hate cold weather but I love to ride, I’ll find a way. I too am constantly re-inventing the wheel Manyakus. Have fun my friend...
explore the possibilities... there endless. ...Blitz
First: Be strong man and never give up!

Second: I never thought about stealing energy from the headers...when you think about it, there is so much energy loss from heat...I admire your creativity! Do you have some pictures?
 

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No pictures, this was before the digital age began. I can however make some sketches and give you some source info if your genuinely interested. Its not like I’m going anywhere for a while. None of it was rocket science. Like I said the missing link was finding the optimum number of coils of copper tube around the header and a thermostat sensor that could control a DC motor on the pump and vary the speed to eliminate the overheating. In my day I would have built a circuit board from scratch but today you can use pre-fabed boards you can find on the internet or contact the “Make” community on the internet and they can hook you up with people who can build it for you cheap. Look for Arduino builders. I believe your biggest challenge will be the creation of your jacket liner to carry the water, “leak free” to what ever parts of your body you want to heat. My proto type was just a seat warmer, had I been more successful I’d have built a body vest first then leg warmers. Let me know and you can leave your email address as a PM and I’ll send you more details. Blitz
 

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Discussion Starter #9
No pictures, this was before the digital age began. I can however make some sketches and give you some source info if your genuinely interested. Its not like I’m going anywhere for a while. None of it was rocket science. Like I said the missing link was finding the optimum number of coils of copper tube around the header and a thermostat sensor that could control a DC motor on the pump and vary the speed to eliminate the overheating. In my day I would have built a circuit board from scratch but today you can use pre-fabed boards you can find on the internet or contact the “Make” community on the internet and they can hook you up with people who can build it for you cheap. Look for Arduino builders. I believe your biggest challenge will be the creation of your jacket liner to carry the water, “leak free” to what ever parts of your body you want to heat. My proto type was just a seat warmer, had I been more successful I’d have built a body vest first then leg warmers. Let me know and you can leave your email address as a PM and I’ll send you more details. Blitz
I am still thinking about your idea...I know how to use Arduino, been using it for lots of projects...I think the bottleneck is the water hose in the jacket...too small hose ID would be harder to pump but they would better blend in the vest...too big ID hose would be easier to pump but bulkier in the vest.
Also how would you control the heat temperature? By flow rate?
 

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Discussion Starter #10
I bought some heating pads and temporarily taped them on a vest. I am burning 38 Watts of heat (13.5V x 2.86A)...it is generating a temp of around 50 degrees C...to be continued

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I am still thinking about your idea...I know how to use Arduino, been using it for lots of projects...I think the bottleneck is the water hose in the jacket...too small hose ID would be harder to pump but they would better blend in the vest...too big ID hose would be easier to pump but bulkier in the vest.
Also how would you control the heat temperature? By flow rate?
Yes exactly, flow rate in unison with the correct surface area collecting the heat. I had to many winds of copper tube. You want the water hot of course but no where near boiling. I never got as far as the vest, I had a vinyl bag I sat on that I made from heavy vinyl that I welded the seams in a fashion that pushed the water thru a path, see the drawing pict. The hoses were auto vacuume lines because they could put up with the heat and pressure. I believe if I could have controlled the degree of heat by flow rate it would have worked beautifully. The heat collection at the headers was so efficient the water would boil after 15 minutes at Hwy speeds. Either fewer winds of copper tube or relocating the coil further down the pipe or increasing the rate of flow or maybe all three, I think would have solved the overheat problem. I’m major A.D.D. and staying focused is not my forte’ so other things took over and I never got back to it, but the problems I faced I’m confident could have been easily overcome. The Arduino and a thermo-couple sensor measuring the temp and regulating the flow by pump speed would work well.
The bag consisted of two sheets of vinyl sonically welded together as shown below ...
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