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Discussion Starter · #1 ·
Any idea what sort of spare output I should have from the alternator?

The reason i ask is that when running with my heated vest on the low voltage warning lights on my heated grips switch comes on. It's a bit weird though: when I first start the bike, when you would expect the battery to be slightly discharged everything is fine and the warning lights don't come on even with every electrical item going. Once it warms up though the warning lights will come on intermittently at any revs and at low revs or with any other item on the switch detects low enough voltage to switch the heated grips off altogether. It could be the switch I suppose. I also suppose this hints at R/R but it was supposedly replaced last year when I was having other electrical problems.

How do I check R/R output? Is it just a case of putting a voltmeter across the battery? I assume I should get 14 volts or so all the time no matter what load is on???
 

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Discussion Starter · #2 · (Edited)
Just got off my arse and looked it up n the Haynes manual. The charging system checks look to be pretty straightforward so will have a go one evening this week.

FWIW the alternator output is 0.315Kw at 5,000rpm.

Regulated output is 13.5 to 15.5 volts at 5,000rpm.

I think this means that with the ignition off I should about 13.2v at the battery. With engine running I should get 13.5 at low revs rising to 15.5 max at 5,000rpm.

The only fix for the R/R is to clean the connections and I assume also clean the heat sink.

I think this also means the bike has about 100watts spare for accessories - based on say 120watts for head and tail lights, plus say another 100watts for fuel pump, fuel injection, ABS pump, ignition, speedo, tacho, etc etc. It's not a lot spare really.... Heated jacket = 50watt, grips 25watts. Add in the wife's heated vest and I am discharging the battery. Hmmmm
 

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Austin mate, with that kind of load you're going to be spending a lot of money between R/R and alternator windings, the max output of the alternator isn't the usable amount of power it's the max!
I personally wouldn't be loading mine to the max with gadgets, if it's that cold just stay at home mate, or take the car!
 

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Discussion Starter · #4 ·
Austin mate, with that kind of load you're going to be spending a lot of money between R/R and alternator windings, the max output of the alternator isn't the usable amount of power it's the max!
I personally wouldn't be loading mine to the max with gadgets, if it's that cold just stay at home mate, or take the car!
I know, but a heated vest and heated grips ain't exactly an extensive set og gadgets.

Just a thought, if I put my ammeter between the earth lead and battery earth I should a read out of actual power consumption shouldn't I? Is this safe to do? I don't really know about this electric stuff.
 

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With the lights and the vests taking over 200w of power I think the alternator will be struggling to maintian the electrics of the bike, yes a meter set on amps will tell you the bikes power use.
One vest maybe but two? Too much I thinks. This will also put the bikes petrol consumption up as well, the alternator will drain power from the engine. I would have thought you could have ECU problems as well when the voltage starts to go down? Tigers suffer from that, they run like dogs with low voltage.
I recall Robster having a heap of gadgets on his Varadero over in Spain, in the morning he had to get a jump start from a fellow camper to get going! Lucky he wasn't middle of nowhere with nobody to jump start him eh? Just pointing out the pitfalls of battery abuse! Sorry! :thumbup:
 

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I think you will find the lights using about 140 watts, add to that the grips, 40 watts, FI and pump another 20 watts, that is 200 watts and the vests ?

To work out the wattage check the fuse size and multiply by 12.
Headlights use a maximum of 60 watts each x2 = 120 / 12 =10, fuse therefore 10 amps. this can be used to calculate the maximum usable wattage and also the fuse size needed for a particular circuit.
 

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I know, but a heated vest and heated grips ain't exactly an extensive set og gadgets.

Just a thought, if I put my ammeter between the earth lead and battery earth I should a read out of actual power consumption shouldn't I? Is this safe to do? I don't really know about this electric stuff.

Hmmm, you'd need a fairly big ammeter capable of measuring in the region of 30 Amps. Not your usual household variety multimeter, I'm afraid. I have one that tops out at 20 Amps.

Going from your figures, alternator output 315 Watts / 12 Volts gives just over 26 Amps.

Even if you take the voltage as higher than 12, say 14 Volts, this will still be 22.5 Amps.

Just a word of warning.



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Discussion Starter · #9 ·
Hmmm, you'd need a fairly big ammeter capable of measuring in the region of 30 Amps. Not your usual household variety multimeter, I'm afraid. I have one that tops out at 20 Amps.

Going from your figures, alternator output 315 Watts / 12 Volts gives just over 26 Amps.

Even if you take the voltage as higher than 12, say 14 Volts, this will still be 22.5 Amps.

Just a word of warning.
Yeah I had thought about that, mainly though about how do I start it with the ammeter attached coz that will be a damn sight more than 30amps.

My multimeter is a B&Q special so probably very average in performance.
 

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I fitted Ring fog lights (2x55watts) and they drained the battery fairly quickly , unfortunately I was at the bottom of a valley and had to push the bike uphill before I could jump start her.
I've changed the bulbs to LEDs and use them as running lights no heated grips (I will invest in a set of muffs though) I do have a heated back protector but dont use it for very long

the moral - dont overload the system it will turn round and bite you
 

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Discussion Starter · #13 ·
Havng browsed the Internet a bit I am coming to the view that the vara's charging system is a bit of weak spot for it. Alternator output of 315watts is frankly pathetic for a fuel injected bike which according to the guide in the link below needs about 285 watts. It's not surprising therefore that adding anything electrically significant to the bike compromises the charging system. Upgraded alternator anyone?

Calculating Excess Electrical Capacity - Learning Center - Powerlet Products
 

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Had a think about this and the measuring of the current might not be as difficult as it first appeared.

Looking at the Haynes Wiring diagram, this is the starter solenoid -



What this shows is that there is no fuse between the battery and the starter motor - which is pretty obvious really.

The 30 Amp fuse feeds ALL the electrics on the bike except the starter motor. So, what you will need is an ammeter that can measure at least 30 Amps in place of the 30 Amp fuse.

To make a proper job of it, you will want to measure the voltage across the battery at the same time.

Alternatively, you could replace each of the Individual circuit fuses with a suitably capable ammeter.

For instance - on the Transalp -

10A - Clock (?)

10A - Fan

15A - Tail light, horn, instruments, sidelight

15A - Head light, passing, brake, start

10A - Ignition

10A - Turn signals

as well as any other extra accessory circuits that you have fitted.



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Going back to the start austin my varas heated grips also suffer in the same way if i put my running lights on 2x55w, i can have either warm hands no light or loads of light and cold hands. but i have had the lights on for several hours without any sign of battery drain.
 

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Discussion Starter · #16 ·
Going back to the start austin my varas heated grips also suffer in the same way if i put my running lights on 2x55w, i can have either warm hands no light or loads of light and cold hands. but i have had the lights on for several hours without any sign of battery drain.
This is what puzzles me - on Saturday I went to Richmond with my wife on Pillion wearing her heated jacket on max (say 4amps / 50watts), my heated jacket on 60%, (say 2.5amps / 30watts,) heated grips, say (2 amps / 25watts). That was for 4hours there and back.

If the bike was using 24 amps / 285watts out of the 26amps / 315watts available just to run, the the battery is draining at 4.5amps. I think its a 12amp/hour battery so in theory it should have been flat after 3 hours. I would have probably had symptoms though after just 2. I didn't though it was fine and the battery seemed fully charged still when I got home.

Either, the alternator output is more than 315 and Mr Haynes is wrong or that 285watts to run the bike is a huge overestimate. This is why I want to put the ammeter on to see what actual consumption is. I like the idea of connecting across the fuse of each circuit as suggested by Lutin. A job for the weekend not an icy cold dark garage.

The other puzzling thing is that when the bike first starts I can switch on every electric component including two vests and press the headlight flasher (dip and main) and the heated grips light still don't go into the low voltage flashing mode. This suggests that one (or both) of the alternator or the R/R is more efficient when cold or that the sensor in the heated grips switch also functions differently when cold.

Another thing to check at the weekend.

The other annoying thing is that it would seem Honda upgraded the bike from a carb model to FI without also upgrading the electrical system. Does the TA700 suffer from similar problems?
 

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there are threads on here where everyone says how good the varadero alternator is, and i agree. ive never had a problem with my heated grips or gps or accessories or anything.
my grips are that type that dont heat up fast when idling, and im glad. why did someone say that was rubbish? at 1100rpm the alternator is barely powering the bike and charging the battery, why twist the lead plates like pretzels making it heat up both ends of a cold metal bar? put the choke on and give it some help while you get your gloves on, and then riding it will give it much more amperage. 3mins on high while riding has my grips too hot to hold onto, but idling they dont feel like they are working at all.
dont forget the varadero lights are on all the time, in fact theyre the first thing that goes on as soon as you turn the key, then you have to count to three for the fuel pumps to charge before starting. if its freezing cold thats already used up the best cranking volts out of the battery.
if you scraped ice off your car, jumped in, started it and turned on the lights, rear window demister, heater, fan, aircon are you surprised when it grinds to a halt 50 yards from your house?
 

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Todays Lesson: how to use a shunt (small resistor in parallel with your ammeter) to effectively change the scale on your ammeter without damaging anything.

Proviso:. you would have to know/measure the resistance of your ammeter to allow you to calculate what shunt resistance to use

e.g. Lets say my crummy ammeter has a resistance of 2 ohms, full scale deflection of 250mA, and the shunt resistor has a resistance of r ohms. I want to use the multimeter as a 30A f.s.d. ammeter.

I want a max current through the ammeter of 250mA so I want the other 29.750 amps to go through the parallel shunt. Multimeter and shunt both have same voltage across them since in parallel, so:
29.750 x r = 0.250 x 2
so r = 16.8 milliohm

Do a P= I^2r calculation to make sure your shunt can handle the power, (e.g. using these figures P=14.8W) then wire it up and off you go.:p

Another proviso: this shunt is a very small resistance - in the real world your contact resistances and connecting leads could affect readings considerably. Nice idea though eh.....;)
 

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Discussion Starter · #19 ·
Update on the alternator output - it is 434watts. Which is a bit more like it and means there is about 150watts or 12amps available for accessories.
 

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look, austin, mate,

its a stonking bike and honda have had plenty of time to iron out all the problems,

so no disrespect but stop worrying and just

RIDE THE ###KING THING.
:D:D:D:D:D
 
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