Heated grips on small scooter (and oddball electrics!)

[stinkwheel]

Long and technical.

Just got a Honda Wave 110 for Mrs stinkwheel for a commuter and she would really like heated grips on it. This is a bit of an ask for the wee thing but I'm thinking through it and will need to do some more testing.

It's pretty much the same setup as a Honda Innova 125 (although not interchangeable). This took me some time to get my head around. It's a "modern" bike with electric start and fuel injection however it only has a single charging coil and has direct lighting just like the older hondas... Except it isn't like that.

The coil feeds into the reg/rec and there is one take-off for the 12v 4Ah battery charging and another for the lighting which is a separate circuit. The lighting only comes on when the engine is running. I had it on good authority that the lighting was actually DC rather than AC, albeit "dirty" DC. I put an LED taillight bulb in and the brake light worked but the tail didn't. I put an LED numberplate bulb in and that did work.

Long story short. It takes a single phase input, half rectifies and regulates it for the battery charging as you'd expect. The lighting (rather cleverly I thought) uses the OTHER HALF of the output. Rather than a split single coil system using half the coil for one and half of it for the other and dumping the bottom half of the waveform like the older ones did, it uses all of the output, the only wasteage is cropping of over-voltage. Put another way, the charging is negative earth and the lighting is positive earth on the same bike!

Not sure how this will play with the LED taillight bulb. A negative earth one definately won't work. A positive earth one shouldn't be polarity sensitive but I have no idea how it will play when asked to be both positive and negative earth (stop light is -ve earth, tail light is +ve earth).

Anyway, to the heated grips. By using LEDs throughout, I'll free up a good 2A of constant draw. Most grips are 4A on full power but I'll check how much they draw on lower settings. What we need to avoid is them drawing so much it stops the FI working. Although these bikes will apparently self-excite and start on a flat battery with the kick-start providing there is fuel in the injector line (again, a marvel of electronics!).

My thoughts are to use the lighting output to trigger a relay for the grips, hopefully halfwave DC will keep the coil energised. Then I can have the grips on a fused "clean" DC supply from the battery but they can only be turned on when the engine is running. My concern is I'm saving most of the power on the lighting side then drawing extra on the charging side.

Then there's the danger of flattening the battery. At a basic level, it'll be doing about 25-30 miles a day tops so simply plugging it into a trickle charger every night would most likely keep on top of it. Another option is a charging indicator lamp (the ones that show green for charged and red for low voltage) so the grips can be shut off if it goes red.

Another thought is one of those voltage sensitive relays like they use for charging leisure batteries on camper vans. Most trip in at 13.8V and cut off at 12.4V. If I fitted one of those it would only allow the grips to be on once the power hits 13.8 and they would turn off if it drops below 12.4. Could be a pest though because I suspect idle voltage will be pretty low and might make Mrs stinkwheel ride it about with the engine screaming to keep the grips on. I'm also not sure if they have any parasitic draw when off. Although combined with the switching relay, it wouldn't be able to draw anything with the engine off.

Or do I run grips on the lighting circuit? Heating elements won't worry about polarity or the cleanliness of the power supply BUT the electronics on the grip heater will probably have a tantrum. That leaves the low-tech sticky pad grip heaters but they are less flexible for low power settings.

Thoughts?

TL;DR

Will a +ve earth LED stop and tail bulb have a tantrum if asked to be positive and negative earth similtaneously?

Will a normal automotive relay trigger properly off "dirty" DC?

Is a voltage sensitive relay likely to be useful?

Should I run electronically controlled grips off the battery or basic grip heaters off the lighting circuit?

These questions may have to be answered by experimentation...
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Nobby the Bastard]

You need a positive earthed led light for the rear and number plate and a negative earth for the brake light.

Good luck....
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Easy-X]

Given the recent discussions on Lithium-Ion batteries how about an entirely independent system.

Grips > manual switch > li-ion battery

For example, run the grips cable to the underseat storage and use a cheap jump-start pack (which usually have a powerbank feature.) Unplug the pack, stash helmet, surreptitiously charge pack at the office and save £££

You could probably even dispense with rigging up a switch if you just get into the habit of disconnecting the power pack when not using the bike.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[stinkwheel]

[stinkwheel]

[A100man]

.. or go old school and fit one of these for the grips..

https://fawkes-cycles.co.uk/images/axa-trio-dynamo-steel-wheel-right-p11427-800_image.jpg
____________________
Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[Nobby the Bastard]

Thinking about how a transfoirmer works, is there some way you could convert the positive earth lighting side to negative using two coils and a suitable piece of laminated iron?

In theory it should work but in reality the losses could make it unviable.

Alternately, make it fully rectified and make it one circuit, that way you you can use the full power of the generator. This strikes me as much more do-able and any regulator/rectifier should do the job.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[stinkwheel]

[Nobby the Bastard]

In this case, this.

(Top picture)


This is true full wave rectification. You just need 4 diodes, but I believe a suitable capacitor to flatten the output from spikes to nearer a flat constant voltage is preferable. It's called Bridge rectification.

https://www.electronics-tutorials.ws/diode/diode_6.html

Further down is full rectification using a coil but that's harder to do by the hobbyist.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Nobby the Bastard]

Actually, when I say 'I believe' I used a capacitor doing the experiment that proved full rectification back when I was in the process of failing A level physic about 33 years ago.

It was a standard experiment that everyone on the course did.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[stinkwheel]

Good, lots to think about. Complicated by the fact that it's complicated. I'm ok with the electrics but not so hot on the electronics of these things

There aren't actually only two outputs from the reg/rec, others go to the main relay and directly to the ECU which I think may be to allow self-excitment on a flat battery. I'm not actually sure what these are outputting or their exact function.

I've attached a circuit diagram for an innova which is broadly similar. There is a distinct lack of any sort of manuals specifically for the FI Waves.

I'm actually moving towards the idea of a seperate removable battery for the grips with a charge relay to allow battery overspill to top it up, a bit like how they rig leisure batteries on camper vans.

I'm going to get more into it at the weekend and see how much it's actually drawing from the battery normally.

If this seems like a lot of faffing, it's because Mrs stinkwheel has pretty bad reynauds and needs heated grips AND bar muffs on her bikes. Especially if she's going to arrive at work in a fit state to do surgery.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Nobby the Bastard]

I'm prepared to bet that the ecu is purely dc side (ignoring the pick up coil) so.converting the lights to negative earth won't be an issue.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Nobby the Bastard]

I've been through the lighting circuit (excluding indicators and brake light) on the wiring diagram and it's not connected to anything else so I would say your ECU side is wholly DC and so full wave rectification should be an easy matter to do.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Islander]

[A100man]

[Islander]

[MarJay]

Ummm...

Battery powered heated gloves? All this putting lithium batteries under the seat and things, but you can get gloves with built in battery pack connections, including battery packs which are rechargeable.

https://buysimple.co.uk/products/rechargable-heated-motorcycle-gloves-battery-powered-warm-motorcycle-gloves?variant=41073196826781&gclid=CjwKCAjw6dmSBhBkEiwA_W-EoKQT3wTab3TkxminI88Wimj0V8h_tg6gDTVel4BXiqBd2NY_8GWf_BoCHkYQAvD_BwE

Something like that?
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[WD Forte]

I doubt the supply is that 'dirty' as well
As said, if the ECU can cope with it then the other components
wont be fussed.
You'd need a scope to be sure but I reckon Honda had a pretty good idea what they were doing and nowadays can do better then raw AC and half wav rectified stuff we'd see on a 1980 CG125

Fowlers parts shows a stator with 12 bobbins and if they're all wound in series with one end to ground and one final output
the overlapping wave forms wont be that bad even before they get rectified and smoothed by caps and the battery itself acts like a big smoothing cap.

Actual usable power/spare capacity will be limited of course
so going all led is a good start.
The guy I know who does Deliveroo all year round has never asked me to fit heated grips to his scoot
But, his screen has a wide base that cuts wind chill on the grips
and he always has those muff things fitted.

If heated grips are really needed I'd fit a voltmeter to keep things simple
It's a cheap handy warning system for any bike to let you
know if alls well electrically anyway.

If heated grips and or other gadgets do suck too much power from the system and the running voltage drops below say 13.7V, you'll know immediately
and can turn them off before they leave you stranded.

As a rough guide with a running voltage of 14V
A grip element of 10 ohms will burn 1.4A or 20Watts
double that 2.8A/40Wfor a pair if wired in parallel
Half that 1.4A/20W for a pair wired in series
With good thermal insulation and wind chill protection 10W
a grip may be enough to keep fingers comfy.
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bikers smell of wee

[sickpup]

I'm trying to work out why you don't just use the genuine honda moped heated grips that are designed for the application and for the life of me can't?

And the rear stop/tail light led problem is quite common, needs diodes on the positive sides of the circuits. It's a problem that turns up when fitting alarms.

[Nobby the Bastard]

I'm not sure how you'd use diodes so you can use a led bulb replacement that does both rear and brake light when the power for one is +ve earth and other is -ve short of making them both the same in the previously described full rectification approach.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[stinkwheel]

[stinkwheel]

Empirical experimentation now shows positive earth stop and tail lamps do not work in this application either, you get the tail light but not the brake light.

I might have a fiddle with a bulb some time, in theory just a case of desoldering the tail light inputs from inside a standard -ve earth LED bulb and flipping them round (assuming they don't just have a common earth on the PCB). It's getting the bulb apart without destroying it that'll be the tricky part.

I have a set of R&G grips on Mrs stinkwheels CBR6. Battery is flat just now but once I get it started, I'll measure the current draw at the different power levels and post it up here.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[sickpup]

[sickpup]

This the latest kit but its quadrupled in price 08ESYK40HG19. Prepare for a heart attack.

The original kit was about £115.

[Nobby the Bastard]

In that case.....

https://www.ebay.co.uk/itm/Oxford-Hotgrips-Essential-Scooter-Moped-Hot-Grips-Motorcycle-Heated-Grip-New-/125239084918?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=710-127635-2958-0
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050