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Discussion Starter · #1 ·
Hi All
Just a quick one here’s the story.
Just gone out to the F650gs and the battery was flat.
I have only recently replaced it; (within the last 3-4 weeks) the bike has only been used once in that time short trip her indoors has not had the time to use it.
So I put the battery on charge, and thought that there must be a drain on it.
HERES THE 3 BITS OF INFO I AM AFTER.
1= What is the draw on your battery ignition off ? (none alarmed bikes)
2= Has anyone disconnected or put a switch in the circuit of their clock?
3= Anyone put a master switch in the main feed or earth for total battery disconnection while not in use.

Reasoning behind asking
Can anyone tell me what the draw on their battery is with the ignition off mine is 0.04 of an amp after 1-2 mins of reconnecting it (once the brain has shut down)
Therefore the std battery being 12 amp/hr sitting doing nothing with that draw will be totally flat in 300 hrs = 12.5 days if the battery is in tip top condition which it was (fully charged and checked) and not very usable after 8-9 days I would think.
As the only item obviously using power is the clock has anyone disconnected or put a switch in the circuit of their clock? or put a master switch in the main feed or earth for total battery disconnection while not in use (extra anti theft).

I know the easy way is to leave it on an opitmate !!!!
I am just curious.

:thanks2:
 

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And never checked the current draw yet as my battery is still strong enough after winter, also no switch between the clock and no need to put any switch in the circuit here.

Ton
 

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Discussion Starter · #4 ·
Battery

Hi Ton
Yours is an ST addmitedly it has a clock my own Funduro can sit for a while no problems has no clock.
But the GS I think (stand to be corrected) the clock has no separate fuse and I think runs via the ECU.
 

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Well perhaps your current draw is caused by something else. I can't imagine that your clock will draw so much current that it drains the battery in that time. I can just start mine up and that means my voltage is not far of 11/12 volt after been not used for 3 months

Ton
 

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Calculation is right yes but seems weird dat the clock draws all that current. O well lucky again to have my ST. And mine has even an old battery too.

Ton
 

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On the GS models, there is also some drain caused by the ECU. You can here some clicking noises for quite a while, after switching off the ignition, & I don't mean from the engine cooling down.

I would always start at the Battery Terminals, checking that they are clean & tight.



 

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Discussion Starter · #9 ·
Battery

Hi
I have looked on a BMW (genuine wiring diagrams) on the single spark they do not show the clock or wiring , but they do on the twin spark which is of no help because on this later type they show it has a separate circuit and gets its power via fuse box.

Wilber
I also checked the draw on inital connection of the battery and like you state the bike must have a small inital systems check or power up as the draw then can be as much as 1-1.5 amps but after 2 mins it settles down to just the 0.04 as previously mentioned.
As the genuine wiring diagams for both models show a difference in the 2 models (apart from the obvious) this might suggest it was an issue (small) with single spark and they changed it on the twin spark and did not run the clock power via the ecu maybe ?
To check my theory I will pop out and disconnect the ecu to see if the clock stops working.
I will let you know.
 

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Discussion Starter · #11 ·
Battery draw no getting technical

Hi
What a way to spend an afternoon when I could be over my friends fixing some 1972-3 Triumph Trident carbs.

Anyway I have been studying my BMW wiring diagrams and playing with the bike.

Some more interesting figures and facts
The instrument console on the 00-03 is not fuse protected
ECU disconnected also all fuses removed = inital connection = 0.085 draw
= after 2-3 mins = 0.001 draw

everything reconnected = inital connection = 0.13 draw
= after 2-3 mins = 0.04 draw
So clock / instrument draws only 0.001 amp at rest
ECU draw = 0.03 amp at rest.

I will check when I get back to work if the f650gs's ECU's have an internal clock (not that it matters)but they/do draw some power to retain machine settings etc.

But was very suprised to find an unprotected circuit on this type and age of bike and very un BMW :puzzled: .

I have worked on bikes for 30 plus years (all various make main dealers) (now in a Police workshop) and this was a suprise and no wonder they appear to have changed it on the later 03 > models.

I would put it on the GT1 but the other workshop have it and I only have access to a GS-911 at work. And these are great but still limited application at the moment.

It has kept some of your entertained I hope , it is just something I need to know now I have come across it.
 

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Just a thought, why did you replace the battery?
Symtoms could be due to V/R problem? plenty of info on FAQ's on this, bit of a weak area on these bikes.
Was it 'not holding its charge' ? Was this tested ? generally under/over charging is the problem with V/R's , but diodes can fail, allowing current to flow back when alternator not producing current.
It would not be the first time that a battery was replaced when it was the V/R at fault. I am talkng in general and cars too, many a garage has replaced the battery as most do not not check charging system.
If you have checked this already then my appologies . . .. . .

If not take a amp reading with v/r disconnected. At least this could be ruled out, as a few members have said some 'electricery problems' can be a bas**rd to find! :wall:
 

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Discussion Starter · #13 ·
V/R

Battery flat so :
Checked battery draw in case the V/R had an issue and gone tits-up in the diode area thats ok. Then procceded to check the rest of the bike draw.

The previous battery was poor due to lack of use so I put a new one on because I did not want any issues with V/R and lack of grunt in the battery for starting as it is her indoors bike and I like it spot on ( no grief).
 

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Discussion Starter · #14 ·
Still no figures on draw

Hi
Just noticed no figures on draw yet mainly from a single spark but would be interested in twin spark figures. Just to log in the old grey matter for future reference.
Remember NON alarmed bikes only.
Thanks
 

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Discussion Starter · #15 · (Edited)
Just for info clock only draw

If any F650 model only has the clock draw on it and the draw is the same as my GS figures.
It would = if the following figures are right and my maths are correct.
Clock draw = 0.001 amp
Battery = 12 amp / 0.001 draw = 12000 hrs = 500 days before totally going flat
 
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Buy an optimate and you won't get these problems. Cold weather, lack of use or even a dude battery could be your problem. Also, as Wilbar regularly stated, those blinking battery terminals work loose with the singles vibration! :big grin:
 

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Well even with mine it won't last 500 days. As it is not just the drain from the clock. The battery will get weaker every day even when not connected. It drains itself.

Ton
 

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Discussion Starter · #18 ·
Battery figures

The figures I quote are just figures from measurements taken and what a battery's potential output should be , not taking into account the normal losses that occur to battery left .
As a battery loses charge its output when it is just over half depleted drops even quicker.
 

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I know that is what you were saying. So your battery might be flat a bit sooner as the potential output will indicate. Not good really that the battery goes down so quickly. But not much that can be done about it so best to leave them on charge if not used too often.
A switch is an idea but that might create new problems again.

Ton
 

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Just my own experiances of owning these bikes for the last 5 years, my single spark bike used to get parked up for a couple of months over the winter without starting it up, and without been on a optimate/charger, and it used to start up reasonably easy. The same happens with my twinspark that I own now. I know there is no statistical data from me just personnal experiance, makes me wonder if there is something more amiss with your machine.
 
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