My MK Indy Hayabusa seems to have a charging problem and I'm not sure what part it is that is causing the problem.

I fully charged the battery which showed 12.4v after charging.
As per the manual I turned the headlights on ran the engine at 5,000 rpm and the battery shows about 12.5v. so not charging.

I unplug the generator and tested the resistance between all 3 yellow wires and I got 0.7 ohms on all.
I then started the engine and tested the voltage from the generator. At idle I was getting 22volts at all yellow wires. If I rev the engine to 5,000 rpm I got 85volts.

I then moved to testing the regulator. I carried out a diode test.
1st I put the red cable on the multi meter to the live and the black to each of the yellow wires. Next the black cable on the multi meter to the live and did the say test. Then I did the same test on the earth.

Multi meter red cable to live
690 730 730
Multi meter black cable to live
0 0 0
Multi meter red cable to earth
690 730 729
Multi meter black cable to earth
0 0 0

Looking at the manual 0.7 ohms is a high reading on the generator but it seems to be giving a good voltage.
Does the fact the one reading on the regulator is different to the others mater?

Hopefully someone can make something of all this.

Here are a couple of my thoughts I am an electronic engineer but new to bike charging systems. One observation bikes do not normally have two headlamps so the power demand is somewhat lower than a car. The key issue is what revs does your BEC do 30MPH if when you have those revs and you get 12.5V then the battery is being charged admittedly only just (at least it is not being discharged). If I remember correctly I get about the same. The alternative is to put on a car alternator. If I am wrong I would like to know. Perhaps more efficient headlights are the answer? Or perhaps I am just plain wrong!

I use one of these:eBay item number:

200537741230

And switch off the headlamps at tick over. I also have very bright running lights that are lower power.

[Edited on 6/5/14 by theprisioner]

Hi,
I have just had the same problem, I recommend to check and clean all the earths from battery and engine. Mine was giving about 12.7v running with no lights and dropping a little with revs. Check voltage output directly from rectifier block if you can. I ended up cleaning earths and changing rectifier (twice) before finally volt output was around 13.6v, may also wire direcly from rectifier to battery to cut out any further weak links in earth or live wires. Also get your battery checked, should be more like 12.7v at full charge.
I'm sure others will be along to offer info but I recommend speaking to cosmick if you can.
Kev

Thanks for the replays.
I don't think it is a problem with the headlamps cause it doesn't charge any better with them off.

On_the_busas when you say you have got 13.6v is that at idle?

Hi,

at idle I believe i'm around 13.4v ish, doesnt move a lot at all with lights on or off.

Thanks for all your posts.
After a conversation with Cosmick I have managed to sort out the problem.

I carried out a few more wiring checks and everything seemed ok.
So as suggested the next thing to try was taking a wire direct from the 12v live on the regulator to the battery. I tried this which made no difference. Next I did the same with the earth wire from the regulator earth to the battery. Tested for charging again and I got 13.6 volts at idle.

So looks like problem sorted in time for the rainy weather.

Glad you got to the bottom of it, hopefully sorted now. I think I will be wiring my earth from Rec/Reg direct too, certainly seems a weak point.

you can also make it easier on the battery drain by reducing the amount consumed - ie convert to HID lighting as it consumes lower amounts, or swap all the bulbs for LED bulbs - less consumption.. etc etc.. it will help.

on a run out i get abot 13.2 - 14v when im ticking along lights off - doesnt really alter much with lights on