Can I pull 12 volts to heat my hands?

[dgk02]

It's getting cold and I must have really crappy circulation in my hands because they always freeze in cold weather no matter what gloves I wear, and I even have pogies. I have a pair of crappy electric gloves that really don't work well so I'm thinking of getting good ones, but they're $170 with a battery pack, $100 if they plug into your 12 volt system - meant for motorcycles. So, since I have a 36 volt 15 ah battery that is more than sufficient for my commute, can I step that down to 12 volts and not harm the rest of the electronics? I already ran wires to operate a front light, but that takes variable voltage and I just run the 36 volts to the light. To go from 36 volt DC to 12 volt DC, what do I need? Should I do it or just get the ones with the battery?

 

[bowlofsalad]

It's getting cold and I must have really crappy circulation in my hands because they always freeze in cold weather no matter what gloves I wear, and I even have pogies. I have a pair of crappy electric gloves that really don't work well so I'm thinking of getting good ones, but they're $170 with a battery pack, $100 if they plug into your 12 volt system - meant for motorcycles. So, since I have a 36 volt 15 ah battery that is more than sufficient for my commute, can I step that down to 12 volts and not harm the rest of the electronics? I already ran wires to operate a front light, but that takes variable voltage and I just run the 36 volts to the light. To go from 36 volt DC to 12 volt DC, what do I need? Should I do it or just get the ones with the battery?

http://www.amazon.com/gp/product/B007YFPD06/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B007YFPD06&linkCode=as2&tag=xbnijgbr-20&linkId=W5BZHWFZNYMPE23L

http://www.amazon.com/gp/product/B005V3K0P6/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B005V3K0P6&linkCode=as2&tag=xbnijgbr-20&linkId=VZZINOKHJZ7YU7ZY

Also, do a search for bar mitts for a little extra warmth.

I've never done this myself, but I've considered doing so.

I don't know if you are already wearing mittens, but they are radically warmer over gloves (the things with individual fingers). Something to keep in mind is some materials 'breathe' and others do not, more breathing means more heat escaping.

 

[dgk02]

Thanks, I actually have the bar-mitts already. They help but not enough.

I'm a bit concerned that the tusk-grip heater might pull too much current and be too hot from some of the comments. Apparently the idea is to put them under the grips! They must get really hot to work like that. I'm thinking that maybe I could put them in some cloth bag and just keep them loose in the bar-mitts. Looks like fun to try though, and much cheaper than the gloves.

 

[bionx 1954]

Hi I have used the heater wire before they work well and do not take much current. I wrapped mine to the handle bar grips and the heat traveled through to my mitts. The golf cart dc/dc converter from Amazon is all you need to power the heaters, and have lots of power for other devices. I bought my grip heaters from Ebay the were only a few bucks shipped.

 

[dgk02]

They're ordered and should arrive tomorrow. I still don't know if I can get them under the grips but it should be easy enough to try. I have a lot of stuff on those handlebars, shifters and brakes and throttle. But if that doesn't work I can always attach them to the bar-mitts by Velcro or something. The wires I have running from the battery to the front light are a pretty thing gauge, I'll have to see how they react to more juice running through them. I guess I can knock it down to 12 volts back by the battery rack since the light is supposed to work with variable voltage. I'll have to see where I can fit the converter.

 

[Ykick]

Hey Dave, did I mentioned the electric vest I use through winter? If you keep your core warmed, toasty blood will reach your hands, feet, etc. E-vest also reduces bulky outerwear. I use an old 3S-4S RC Lipo battery to power my vest which needs about 5A full ON. Of course it never runs 100% of the time once the thermometer/regulator kicks in.

DC-DC convertor would work but 5A/60W peaks require a rather large and expensive convertor so I just opt for the battery.

 

[bionx 1954]

I just wrapped the heater on top of the grips and used heat shrink or electrical tape to hold them there. I do not think under the grips would transfer much heat threw the grips.

 

[dgk02]

Hey Dave, did I mentioned the electric vest I use through winter? If you keep your core warmed, toasty blood will reach your hands, feet, etc. E-vest also reduces bulky outerwear. I use an old 3S-4S RC Lipo battery to power my vest which needs about 5A full ON. Of course it never runs 100% of the time once the thermometer/regulator kicks in.

DC-DC convertor would work but 5A/60W peaks require a rather large and expensive convertor so I just opt for the battery.

I thought about that but my hands just freeze no matter what. The other day it was 42F and my hands were freezing inside gloves. Other folks were biking without any gloves at all. My hands just get cold, or I have no resistance to pain. My core was warm, three layers that morning. Too much actually. Each winter I have to relearn my whole dressing scenario.

 

[teklektik]

I have similar "warm core/cold extremities" problems.
If the grip heaters don't pan out:

I use First Gear glove liners with a wireless PWM temp controller clipped to my jacket zipper pull. Liners are very thin and flexible, you can use any glove you want, and the control is easy to adjust, even with fat 3-finger gloves. Heat is generated inside the glove and uses very little power. Highly recommended.

For really long cold rides I plug Gerber heated insoles into the second temp control channel.

+1 for dedicated batts. Even though I already have an on-board 10A converter I use spare Headways in a small bag with cross-body shoulder strap. Goes with me for dismounts with no wire fiddling and makes the heaters handy for other winter activities.

 

[dgk02]

So while cleaning up the room, I came across a 11.1 volt Li Ion battery that I used to put neon tubes on the bike. I haven't used those in a year since so many nice lights have come out. I think maybe I'll use that to power the grips instead of using the bike battery. It's 2400 mAh so that should last for a while. How long? No idea. Anyone have an idea?

I still don't know whether to use the heated grips under the grips or just leave them loose in the pougies.

I did run them through the 36/12 volt Golf Cart reducer, and they got very hot. But I have to try them now with the 11.1 volt battery and see how they do. One can certainly go under the grip, but I'm not sure about the right side where the grip shifter is. I'll have to play around a bit, but I think maybe my hands won't freeze this winter.

 

[Wrecker Magoo]

Please give us an update later once you've had a chance to play around with it., Let us know what you tried and how it worked out for you.
My hands are always freezing too..

 

[dgk02]

I tried the 11.1V battery and the pads certainly got hot. On low power (the kit has two settings) they're too hot to really keep a hand on. I'll try to install it over the weekend. I'll put one under the left grip just to see how easily it goes on. I've had trouble with grips before; nothing really holds them on except friction and once they get loose they seem to stay loose. But that side has a mirror that will prevent the grip from slipping off. There is a shifter on that side but it's the big cog and that normally stays in the highest gear. The right side has the cassette shifter as well as the throttle so everything is pushed over a bit and the pad would have to go partly under the shifter. I'll see how I can do it - motorcycles don't shift that way as I recall, I think it's all done with the right toe so they don't have to worry about having it under a moving part.

I was going to order a second battery since I'm not sure of the condition of this one, but they're around $50 for a 3000mAh or so, plus expensive shipping. I think I'll wait and see how this one holds up.

I think I prefer this to using the main battery. Less complicated and if I forget to turn it off at least I'll still have the main battery to power the bike!

 

[dgk02]

Quick update. The shifters on my bike are too tight to fit over the heating pads on the handlebars. The grips fit over them fine, but I can't use it that way because there is just no way the shifters will fit on top of the pads. My handlebars curve so there isn't enough room to move the shifters over enough to clear the pads. So, I just stuck the pads on the inside bottom of the Bar-Mitts. I have not yet tried them with a real test, probably Monday will be cold enough. They won't be necessary, since it will be at least 35F when I start out, but I'll get some idea whether it will work.

The wiring is a bit of a pain. I'll try to get a pic up here. There are SO many wires around those handlebars since I have a battery powered light as well as a light running off the main battery at 36 volts.

One question is how long the battery will last. It's 11.1 Li-Ion left over from another project, and 2600 mAh, which I guess is 2.6 Ah? That seems like a fair amount of power. I also have a spare 6 volt NiCad from one of the bike lights that I can press into service if the other doesn't last for 25 miles.

Hopefully the pad won't get so hot that it actually melts the Bar-Mitts. I doubt it, and there will be nice cold air on the other side of the Bar-Mitts to keep it cool. I'd hate to have them melt on my hands.

 

[Wrecker Magoo]

Thanks for the update.

grip shifters or trigger shift??

 

[friendly1uk]

My mind keeps coming back to wire wound ceramic resistors placed within the bar. It's getting the wire in that holds me back from trying. M/C riser bars with the cross brace might take a hole though without significantly weakening the bars, when used as a simple commuting tool.


If I put fingerless gloves on sat here at the pc, my finger tips feel cold almost instantly. I believe it is conservation of energy. If my hand is warm, that is enough blood. I'm no doctor though.


I just picked up some gloves with a mitt built in. Quite good: http://www.ebay.co.uk/itm/171126486028?_trksid=p2059210.m2749.l2649&var=470287734744&ssPageName=STRK%3AMEBIDX%3AIT
You can have the dexterity of a glove one hand, and warmth of a mitt on the other. Ive found mitts are really just for long non-technical rides, while gloves are better if your using the controls a lot.

Just a couple of ideas to mull over when your meant to be sleeping

 

[friendly1uk]

Oh, some proof. My finger tip was 29.5c for some time. Put on a fingerless glove and within a minute I was down to 28.5c and dropping. 27.2c now I have typed this. Freezing... I'm taking them off...

 

[dgk02]

My mind keeps coming back to wire wound ceramic resistors placed within the bar. It's getting the wire in that holds me back from trying. M/C riser bars with the cross brace might take a hole though without significantly weakening the bars, when used as a simple commuting tool.

That's an interesting thought. I could put the pads into the handlebar instead of on them. The sticky side should be able to pretty much hold them to the inside surface. I'd need to run the wires out the ends, and one end has a mirror in it so that would be a problem. It's something to keep in mind in case the "stick to inside of Bar-Mitts" concept doesn't pan out.

And the pad that I tried to stick to the handlebars isn't sticking well to the Bar-Mitt. I think I might need to stick it to some velcro and stick that onto the Bar-Mitt.

The bigger problem is that the battery, on low, made it all the way to work but quit halfway home. So i'll need to carry the charger or pick up another battery pack. All-Battery has a Li-Ion charger for 11.1 packs for under $20, but as I recall their shipping is pretty expensive. And I'm likely to want the pads on high. The good news is that I did feel the heat but we'll see how it works when it really gets cold. By Wednesday it will be in the thirties so I'll have more of an idea.