# heated grips



## Pauly1971 (Feb 23, 2020)

Hey.

I purchased a Kimpex 12-170 handlebar heaters. I installed them by splicing in the headlight wire. They do work but they are very weak on high.

What did I do wrong?


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## crazzywolfie (Jun 2, 2014)

they might need dc power to really put out heat and headlights are usually a/c. that is how the ones i installed on my machine are. they didn't like a/c but warm up pretty nicely when running on d/c.


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## RIT333 (Feb 6, 2014)

I didn't think that a resistance load cared whether it was ac or dc. I would guess that your alternator isn't large enough to power both the lights and hhg. I had the same issue with my Toro, so I put a couple of switches so I could have light and/or hhg, but with both, the light got dim, and hhg was not as hot.


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## Pauly1971 (Feb 23, 2020)

Would an ac to dc rectifier work?


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## crazzywolfie (Jun 2, 2014)

it would but may be best to try running some dc power to them first and see if it makes a difference. maybe try hooking them to a 12v battery or something first for testing purposes. i tested mine before i even installed them.


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## Pauly1971 (Feb 23, 2020)

I actually tested them yesterday with a car battery and they do work well.


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## melson (Feb 9, 2015)

A pure resistor such as your grips doesn't care in the least whether it's provided ac or dc. 
What it does care about is the amount of power being supplied. 

From your comment that the grips warmed when supplied from a 12v car battery source then it's reasonable to conclude the engine alternator isn't rated to supply the power being demanded by the resistance value of the grips. Or, at the least, they're not being provided the power their resistance value can draw.

I think I remember the spec for my Ariens with heated grips as drawing something like 3 amps (at I-don't-know-how-many volts). That's a fair amount of current and many manufacturers didn't sell their products with alternators capable of supplying more than 20 or so watts. Because, if the blower wasn't built with heated grips then why waste money installing a more powerful alternator than is necessary? Usually, when a snow blower is built with heated grips it has more like 30 to 50 watt alternator installed.

There are many exceptions, like always, and many blowers without grips or lights were, nevertheless, built and pushed out the door with 50 or 60 watt alternators, whether they needed it or not. 

Those are just guesstimate numbers; I don't have the specs for every blower. But the idea is valid.
Hope this helps.


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## Pauly1971 (Feb 23, 2020)

Ok. I understand. I'll buy better gloves.

Thanks for the help.


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## orangputeh (Nov 24, 2016)

Pauly1971 said:


> Ok. I understand. I'll buy better gloves.
> 
> Thanks for the help.


you can search thes forums as this question comes up quite a bit. someone here suggested installing a different rated stator or coil. I don't know which.


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## melson (Feb 9, 2015)

[I said:


> Pauly1971;1725087]Ok. I understand. I'll buy better gloves.
> [/I]


Hah! Yep. As for gloves the best I've used in cold and wet conditions are the top-line Columbia. I hate to be a brand booster, but those $85 gloves never fail to amaze; even if fully soaked, dripping wet, my hands are warm. They might feel squishy but it's a warm squish. Never had gloves able to do that, don't know how they do that.


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## tabora (Mar 1, 2017)

Did you wire the grips in parallel or in series? In series, I think they would be about 1/4 the amount of heat?


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## crazzywolfie (Jun 2, 2014)

i just went and played with mine. if mine are putting out heat on a/c it is my temp gun can't pick it up. same a/c output with a bridge rectifier and i start getting heat out of them. i think they are meant to run on dc despite the fact they are advertised as being good for both a/c and d/c. it doesn't even have to be fancy dc. the single diode on the 1 line of my engine seems to work good for powering the heater.


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## Shovel (Mar 26, 2019)

crazzywolfie said:


> i just went and played with mine. if mine are putting out heat on a/c it is my temp gun can't pick it up. same a/c output with a bridge rectifier and i start getting heat out of them. i think they are meant to run on dc despite the fact they are advertised as being good for both a/c and d/c. it doesn't even have to be fancy dc. the single diode on the 1 line of my engine seems to work good for powering the heater.


You have something else going on.
Amps times volts equals watts regardless of polarity or alternating polarity.
A single diode inline on one leg would block that leg half the time on AC ...cutting your power consumption in half



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## crazzywolfie (Jun 2, 2014)

you would have to talk to briggs and stratton about about the dual output stator coil. as far as i know the only difference between the a/c and d/c terminal is just a diode. it puts out 12vdc and it runs the handle bar warmers like it should. the a/c terminal only works on the heaters with the bridge rectifier. i really don't understand it.


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## Shovel (Mar 26, 2019)

crazzywolfie said:


> you would have to talk to briggs and stratton about about the dual output stator coil. as far as i know the only difference between the a/c and d/c terminal is just a diode. it puts out 12vdc and it runs the handle bar warmers like it should. the a/c terminal only works on the heaters with the bridge rectifier. i really don't understand it.


A bridge rectifier changes AC to DC with the only a minimal loss at the diodes.
DC doesn't use diodes unless for reverse polarity protection.. in that case it is almost fully blocked 
The warmers will work fine on AC .. standard filament light does as well.
The rectifier is needed for battery charging or polarity specific devices ...such as a solenoid or LED lights .


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## melson (Feb 9, 2015)

@crazzywolfie, when rectifying ac to DC the power can increase, depending upon the circuit used to rectify. Sometimes dramatically so. 

The bottom line is a pure resistance doesn't care whether it's ac or dc. It only cares about the power being supplied.


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## Shovel (Mar 26, 2019)

melson said:


> @crazzywolfie, when rectifying ac to DC the power can increase, depending upon the circuit used to rectify. Sometimes dramatically so.
> 
> The bottom line is a pure resistance doesn't care whether it's ac or dc. It only cares about the power being supplied.


A rectifier only points which lines to send the current to
One wire is positive and one is negative(DC) With AC they aren't /they switch back and forth depending on which wave it's on.... . A full wave bridge rectifier directs the current from one wire of the AC to another wire on your full wave bridge rectifier and it does the same thing for the other wire as well at the same time..if it's positive at the moment then it goes to the positive side if it is negative at the moment it sends it to the negative side...there are two diodes in that section..while at the same time..the other AC wire is doing the exact same thing so you have four diodes... anything less and you are not taking advantage of the full wave...and cutting what's available in half.
You can not create more power(watts)...you actually lose a touch as heat as the diodes are doing their thing.
Power (watts) can not be gained in the conversion
A full wave bridge is merely four diodes with the job of blocking or passing current.
The top and bottom wires are your ac wires... notice how the two diodes are pointed the same way to the negative of what is to be our DC wire...and the other two are pointing the diodes to the positive side of what is going to be our DC wire.. those diodes only pass one way.. which is how we get DC... Technically if we fed the AC lines with DC ... it will still direct that current to the correct 'outs' for our DC...even if we reverse the wires on the AC side again... the current is always directed to where it needs to go....Just think of them as four gates... anything less interrupts the possibility of a full time pass and reduces available power.











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## RIT333 (Feb 6, 2014)

Shovel said:


> You can not create more power(watts)...you actually lose a touch as heat as the diodes are doing their thing.
> Power (watts) can not be gained in the conversion



Nuts - There going my plans at making a perpetual motion machine ! LOL


Yep - I was going to make the same statement as you about losing power in the conversion.


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## crazzywolfie (Jun 2, 2014)

Shovel said:


> The warmers will work fine on AC .. standard filament light does as well.


maybe in theory you might be right but in reality i could not get mine to work on a/c. they would only put out heat when fed d/c power.


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## melson (Feb 9, 2015)

Shovel said:


> _You can not create more power(watts)...you actually lose a touch as heat as the diodes are doing their thing.
> Power (watts) can not be gained in the conversion_
> 
> 
> ...


That should be theoretically logical. In practice it becomes complicated, . 

Remember, ac voltage is rms with a (hopefully) 50% duty cycle. A full-wave rectified DC, on the other hand, gives something closer to 100%.
When you add capacitance things become complicated; it has been shown such 'extra' power is caused by harmonics.
Unfortunately for me, the ability to further discuss this with any insight is above my brainpower ('can we get an electrical engineer over here?')... 

The bottom line is that, apparently, in some cases a pure resistance (with transformer action) sees a higher average power.

Here's but one discussion if you're curious: https://electronics.stackexchange.c...-twice-as-much-ac-current-through-transformer


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## Shovel (Mar 26, 2019)

melson said:


> That should be theoretically logical. In practice it becomes complicated, .
> 
> Remember, ac voltage is rms with a (hopefully) 50% duty cycle. A full-wave rectified DC, on the other hand, gives something closer to 100%.
> When you add capacitance things become complicated; it has been shown such 'extra' power is caused by harmonics.
> ...


Capacitance can smooth out the wave.. in a simple circuit such a heated grips it is not needed.
Capacitance is 'storage'.. but that storage had to be filled to begin with so there is no free gain
No circuit is 100 percent efficient due to heat losses along the way... The more complicated the circuit the more the actual losses.. A person then may have to step the voltage back up with a transformer.. but that is also another loss.
A higher voltage does not equate to more power.. watts is power.. which is amps times volts.
They have a much more complex than what we are dealing with.

The rule still however still applies.. power can not be gained in the conversion.
If that was the case we could rig one up in the garage from the receptacle and create more power that what we are actually using.. then repeat and repeat and so on then power a city .. it can't happen.


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## dugt (Jan 23, 2020)

Cheap mittens are warmer than expensive gloves and you don't need the dexterity of gloves when operating a snow blower. Also, you can buy battery powered heated mittens and gloves.


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