F800GS/F650GS Electrical System Capabilities

First of all....I am not an electrical engineer, but I like to think that I have a basic understanding of how electrical systems work.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
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There are several small discussions out there regarding the capacity of the BMW F800/F650GS electrical system and my goal here is to draw those discussions into one thread. Hopefully, this will create a single thread that describes current (read amperage) capabilities of the accessory plugs (a known trait of the BMW CanBus system), the available room to add accessories, and the capabilities to increase the available capacity of the system (either through aftermarket/optional alternators, alternator modifications, or reducing the draw of the standard systems).<o></o>
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The motorcycles currently have 400W alternator. (I expect the alternator size to grow over the next few years just as it has on other BMW models. Hopefully, those alternators will be direct bolt-on replacements for the current alternator.)<o></o>
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Questions:<o></o>

• Does anyone know what the standard system draws? (Obviously this will be affected by a couple of the features on each motorcycle; <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-comffice:smarttags" /><st1:stockticker>ABS</st1:stockticker> and heated grips.) <o></o>
• What capacity is available to add accessories such as additional lighting, heated accessories, etc.? <o></o>
• Can we increase the available capacity of the system by upgrading to HID lights or other methods, thereby reducing the lighting draw and increasing overall capacity? <o></o>
• Is it possible to have a motor shop rewind the alternator to increase the alternator output?<o></o>
• Can someone provide the allowable current capacities of the accessory plugs (the BMW plug next to the ignition, the <st1:stockticker>GPS</st1:stockticker> pigtail and the alarm system pigtail)? <o></o>

Obviously, there will be other questions so please ask at will.<o></o>
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I ride year round and want to make certain that the accessories that I run will not overload the electrical system of the motorcycle. If the total does overload the system, what combinations can I run to prevent overloading the system?
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The accessories I am or want to run are:<o></o>

• <st1:stockticker>GPS</st1:stockticker> (Garmin Zumo)<o></o>
• Heated clothing (currently Gerbrings jacket and G3 gloves)<o></o>
• Additional front lighting (TBD)<o></o>
• Additional rear lighting (Dual-function 16 LED Hyper-Lites)

The accessories my F800GS has are:<o></o>

• Heated Grips<o></o>
• <st1:stockticker>ABS</st1:stockticker><o></o>

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LET ‘ER RIP!!!<o></o>
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Hmmmmmmmm I don't know either.... one thing I have heard is that the standard DIN plug on top of the tank is limited to 5 amps (70 watts or so) at which point the CANBus shuts off power -- so most heated clothing might (?) have to be connected via alternate means....

The aftermarket grips seem to be roughly 35W .... so that might be a good working number for the factory grips as well...

Some of the clothing could draw big wattage ... very dependent on details it appears...

You could try "working backwards" and see if you could stay under say a 300W "budget" ... I can't imagine that the bike its self uses more than 100W not counting the heated grips??? (that's a guess) ;-)

Jim

400W doesn't sound like a whole lot to me. What was BMW thinking? I'm kind of curious to see what the bike pulls in stock form as well. When I get some time this winter I'm going to use some equipment from work to determine total draw. I'll post up my findings when I do.

FWIW, here's a couple formulas to help figure out current and power.

E = I x R
P = I x E

E = Voltage, I = Amperage, R = Resistance, P = Watts

That is true. I just ordered one of these from Powerlet Products. It's a replacement for the CAN-BUS-powered outlet next to the ignition. You use the same hole, and it gets wired directly to the battery.

http://www.powerletproducts.com/shop-by-vehicle/product/low-profile-powerlet-socket-kit-12/164/690



I'm also going run an PKT-001-48 SAE cord...

http://www.powerletproducts.com/product/sae-battery-leads-heavy-duty-15-amp/107




...back from the battery to under the back part of the seat, and tap one of these into my panniers, for charging stuff:


http://www.powerletproducts.com/product/luggage-electrix-connector/286/



Rob in Seattle

Believe it or not, our MOM does tell us the wattage requirements of some of the components on the motorcycle:

Page 129 confirms the electrical rating of the onboard socket is 5A.

Page 130 details the wattages for the bulbs. If my math is correct, the motorcycle lighting system consumes 115 watts of power with the high beam on and 60 watts with the high beam off. Turnsignals consume 20 watts (10 front/10 rear) unless you are running LED turn signals.

So what does the rest of the CanBus consume? ABS? Heated Grips?

Rob, I like your ideas.

I received my Centech AP-1 fuse block today. Anyone out there have any good pics of their AP-1 installation on their F800/650twinGS? My immediate plan for the fuse block is to supply power for my heated clothing (gloves - 27 watts, jacket liner - 77 watts) ...once the weather gets cooler. Eventually, I plan to add aux lighting.






Still trying to figure out what the system can handle....

Maybe someone can tell me if the following is a silly solution to that question:

I had planned to purchase and install a voltage meter before a single electrical farkle was installed. I'm thinking of something similar to that shown below, but maybe not so fancy. My theory was that if the alternator was not able to keep up with power demand as accessories were added, the voltage meter would show a value less than that shown when no accesories were installed.



Granted, this won't tell you the answer until you've exceeded the limit, but it bypasses a whole bunch of research and head-scratching beforehand.

why not use the extra cutout space on the right side of the key, and have two plugs?

There are two threads on F800Riders.org that should answer your question:

http://f800riders.org/forum/search.php?searchid=259360 -- Overview
http://f800riders.org/forum/showthread.php?t=14126&highlight=alternator -- Specifics in post 2

There is also a complete writeup of how to add an additional power outlet on the GS in the F800 Riders Hall of Wisdom:

http://f800riders.org/HoW/showentry.php?e=29&catid=6

Rob,
This link does not work for me.

George has shown us a wattage value that is too much (175W) which is great, but how much can we use before supply is overpowered by demand?

I've already used this one to wire up my Zumo. Thanks.

Sorry - http://f800riders.org/forum/showthread.php?t=8539

The engine computer and fuel injectors & fuel pump consume "something"... but I've got no good idea how much...

I can't imagine the ABS system drawing enough to worry about on a "steady state" basis...

See my other append on the heated grips... maybe 35W?

Jim

[quote='Flagger]Maybe someone can tell me if the following is a silly solution to that question:

I had planned to purchase and install a voltage meter before a single electrical farkle was installed. I'm thinking of something similar to that shown below, but maybe not so fancy. My theory was that if the alternator was not able to keep up with power demand as accessories were added, the voltage meter would show a value less than that shown when no accesories were installed.



Granted, this won't tell you the answer until you've exceeded the limit, but it bypasses a whole bunch of research and head-scratching beforehand.[/quote]

I believe your theory is correct!
Nominal voltage (if the alternator is keeping up) should be on the order of 13.5V or higher...

I was going to get one of these - simple and small

http://www.cyclegadgets.com/Products/product.asp?Item=BOVOLT

but i notice that the light stays "green" all the way down to 12V which is not good........ so still looking....

Jim

Most electricians and auto technicians have inductive amp clamps that will tell you exactly what you want to know, all you need is access to the positive battery cable. No disconnecting wires required.

I used a Gerbings Accessory Socket ($25.00) wired directly to the battery and the spare hole cut-out on the right side of the ignition key. Runs my Gerbings jacket and G3 gloves no problem - toasty warm on these now cooler fall days here in Minny-Sota.

Cowboy2

Good plan! Perhaps want to put it on the output of the alternator so as to be able to measure the total output "required" from the alternator for the load applied ... or note the fact that the alternator output is already "pegged" :huh....

There are a couple of guys over on the UK forum that have mounted their Centech AP-1 fuse blocks up under the false tank cover.


Anyone else out there got one already? If so, where'd you mount it?


Pics appreciated!!!

Same place: under center panel.

Thanks, is your panel loose or do you have it fastened down?

The AP1 is lose. But the wires hold it steady. The Starcom1 actually has velcro on the bottom to keep it from bouncing about.