When the engine is at low speed (idle) the battery will be providing some power, more if you have stop light on, more if you have indicators on, and much more if you have the headlights on. At idle the alternator is at minimum power and may only just provide power for your ignition system. :(

As the engine speed increases the alternator power increases too, but it is not a linear relationship. See the Car and Deep Cycle Battery FAQ, Battery Manufacturers and Brand Names List, and for info (section 5).

From your given info I suspect the dual hi beam was added by an over enthusiastic owner .. who only used it for short periods of time .. or who realized he had a problem and sold it off. :thumbdown:

Remove the dual high beam

At idle the bike should charge fine with a normal 60/65w headlight, and 5w rear, and all the instruments working......Mine does, i've got a voltmeter fitted to the bike.

Again....Turn of one of the front lights, and you should be good to go.

You can always save a few watts if you get a BAY15D SMD bulb for your rear stop/brake lights!

It WAS the law. That law has been repealed as the statistical results said it made no difference. So you can now turn your headlight off in Australia. But some motorcycle manufactures are not equipping their bikes with the switch... makes it common with some other markets who also don't have a headlight switch. But you can legal turn the headlight off, you just need a way of doing it.

Faulty wiring! I realised that I had checked that there was no voltage drop between the regulator and battery, but with no load and a bad battery! Checking again under full load and with a new battery, I found almost 1 volt drop from the regulator to the battery. So I cleaned all the contacts, added solder to the joints, thickened the wire and shortened the amount of wire between the regulator and battery (all on +ve side). Now it'll maintain 14.4V with normal lights, and 12.9V with the dual hi beam, which is not ideal but at least should not drain the battery. To save power I got some of those delivery scooter hand covers so hopefully I won't need the heated handgrips as much (although I am loath to make my tenere wear them, I think it's better to look like a pizza delivery bike than always ask for a jump)

Thanks for the help, I'll post here again after testing the viability of the dual hi beams on a bit of a ride.

12.9 won't damage the battery in the short term. But you'll want to run it higher 10 to 15 minutes before your stop to have enough energy to start the bike the next morning. As you'll probably want to run at a slower speed with the light reduction that will cool the motor too, a good thing to do.

Some led's for the instrumentlight, and the rearlight should save up some extra wattage to get the voltage over 13v.

I'd still use an on/off switch so you could turn of one of the frontbeams, when its not really needed. Or perhaps change one of them for a "smaller" one in the 30-50w area, it should really help :)

The saving is very small when compared to the overall power.

The instrument lights are 3 watts each, the tail light is 5 watts .. so if LEDs save half and you have two instrument lights you'd save some 7.5 watts out of some 168 watts ... less than 5% saving.

LED's save way more than half, they use well under 1w each.

Theres the 2 bulbs for the indicators, and the rear/brake-light. Theres also the parking light. He could change the neutrallight and the high beam indicator, eventhough they're not on much.

He's running right on the egde, im sure the charging system would be thankfull for an additional 10w "buffer"

Well, I took it for a ride, mostly on hi beam except when I was too high (cold) and had to turn the heated handgrips on. Left with the battery at 12.86, returned and it was up to 13.05. So it looks like the problem is prett much solved. I like the idea of switching out to LED where I can, as you say a bit of a buffer would be a good thing, but I may put that off for a while until I have a good workspace for 'nice to have' items.

Quick question about the LEDs - do drop in replacement bulbs for the dedicated hi beam projector exist? I remember doing a bit of research a few years ago and found that the throw pattern would be useless. Anyone know of a change to this situation?

There are H4 SMD bulbs but they are expensive (around 50€ if you can find them cheap) and the maximum I've found had only 300lumen...

The only way you'll save some real wattage is if you go with HID ballasts and bulbs! check them out!

If I had the spare cash right now I'd get an HID projector lens preferably with a 3" diameter lens and with an H1 4300K 55w bulb!

In the XT600E stock headlight you can only fit a 2.5" projector lens with a proprietary bulb (unless you hack the sh*t out of your headlight reflector!

BAY15D SMD rear brake light 1.5W: (stock is 21W brake light and 5W rear "presence" light)

1157 BAY15D 18 SMD 5050 Pure White Tail Turn Signal 18 LED Car Light Bulb Lamp | eBay


You can also go with LED turn signals/blinkers whatever you wanna call it!

Vando ;)

Its actually only running light in the back that is worth mention here, turn signal and brake light is on so short of a time on that there is no point counting them here.. Original there is 55W headlight bulb, buy HID 35W then you really save power.

HID's is illegal many places, and the lightpattern in a stock reflector sux. I wouldn't call it an option. :innocent:

Dont agree, the pattern isnt much different from stock. And with 35W no one will tell the difference from stock. The rules about HID on motorcycle i dont know about, if the light strength is about the same as stock and colour is same i cant see any problem. Have you tried HID on your bike?