Charging Problem?

[ChasF]

The battery keeps going flat on my 100GS. It seemed to decline last winter despite being on a trickle charger (BMW one) when not in use.

Yesterday I measured the voltage across the battery on the 100 and 80. on the 100 the light goes out as normal but voltage peaks at 13.5V. On the 80 the light just dims a bit but the voltage goes up to 14.2V. Could just be differences between the batteries??

Any advice appreciated.

 

[MickDB1]

One will probable have the original regulator tuther would prob have a high out put one
Its the red box under the tank with a plug under it = that an original
My high output is aluminium capped
HTHY

 

[ChasF]

The unit on the 100 is a red plastic unit marked 14Volt. I've never had a problem with it so it is the original unit (but then I've never measured the battery voltage before).

I would expect the both the standard and high output to have the same maximum voltage but I think the high output one just reaches the maximum voltage at lower revs.

The problem seems to have gone away after I cleaned the earth connection on the gearbox although it looked OK to me.

 

[Steptoe]

My high output is aluminium capped
HTHY

That could be an early original mechanical regulator. If you open them up it's adjustable.

The later standard regulator is red topped, the high ouput is black topped.

 

[MickDB1]

I would definately say Steptoes is always right - cos he is

But only reson mine is ally topped is its a new un that was ordered from Thunderchild with an updated newer styled Diode board last year

Best thing would be to measure your voltage at the battery when the bike is at 1500 and at 4500 revs
Then do same to yer other bike if they differ swap the regulator over and check again
There are some regulators for sale on fleabay that let the voltage rise to over 14v for about 20 quid
I do not know there quality
Thunderchild stuff has been first class and the postage delivery time it bang on toooooooo - that is for me anyway
HTHY

 

[Valker]

That could be an early original mechanical regulator. If you open them up it's adjustable.

The later standard regulator is red topped, the high ouput is black topped.

I have a black one on my GSPD, I'm told its the high output(Police type) Not sure what the differant is,can Steptoe enlighten me PLZZZ,,, I also have the 400 watt alternator fitted,dose this mean I can run my house off the bikes power!!!!!

 

[ChasF]

The bike was fine on our trip last week (Millau Viaduct, Gorges du Tarn etc.) so have to asssume that cleaning the connection on the gearbox solved the problem.

Front brake needs some work

 

[MickDB1]

I would still get the multimeter measurements off the battery teminals at both revs - also sometimes with these bikes you get a slight glow on the red charge light - mine was caused by a diode board fault that showed itself only when the bike got hot

 

[electric_monk]

The bike was fine on our trip last week (Millau Viaduct, Gorges du Tarn etc.) so have to asssume that cleaning the connection on the gearbox solved the problem.

Front brake needs some work

Don't think the brake is the problem.....