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Discussion Starter · #1 · (Edited)
Even with the OBC option riders of F658GS & F800GS twins are not able to monitor battery voltage. I was a bit disappointed by this omission as some other BMWs with the OBC do have a voltage display (650 XCountry as an example).

Anyway, since these bikes have a "modest" 400watt alternator and a dead battery means a dead bike I figured I'd add some type of voltage monitor.

After reviewing the various options I decided to go with the HEADS-UP LED Voltage monitor by SDC: http://www.signaldynamics.com/products/Modules/HUVM.asp

if above link does not work try this one:

http://signaldynamics.com/index.php/products/led-lighting?page=shop.product_details&flypage=flypage.tpl&product_id=56&category_id=44&vmcchk=1

The LED shows system voltage level in 5 steps:

Flashing Green - Voltage Above 15.25 VDC - This prolonged over-voltage condition can destroy batteries, especially gel-cells.

Steady Green - Above 12.9

Steady Amber - Above 12.6

Steady Red - Above 12.1

Flashing Red - Below 12 VDC - During this condition, if the engine is running, do not shut down until service can be provided. Restart of engine is unlikely. Reduce electrical load.

When powered up it goes thru a cute little boot-up showing off the various colors and then settles in based on the current voltage. For the first 10 seconds or so the LED is very bright, then it dims down a bit. It is very readable in all but the brightest sunlight but no so bright that it is annoying at night.

OK ... so cutting to the chase:

Let me recommend that you also review this article by twisticles which is very nicely done (a lot neater than mine will be):

http://f800riders.org/HoW/showentry.php?e=29&&epostid=77#post77

The installation was really pretty straight-forward.

Here are the key components for the project:



The white plug with 3 yellow wires is the GPS adapter/repair plug which mates with the plug on the bike. Rob sells these in the F800Depot.com site.

The LED voltage monitor device - note the heat sink is rather large but i managed....

And last but not least by any means....
The key component of this project was a bracket I made with a friend's help.
(if you had not yet noticed that I get a bit "anal" about my bike you will have drawn that conclusion by the end of this article.... )

Anyway the custom bracket fits into the triangular shaped notch between the speedo. & tach. it is three sided and picks up as a mounting screw the screw on the back side of the tach. It was kind of a bitch to make....

Here's a slightly better view of the bracket - I apologize for the fuzzy pic. I didn't realize the pic. was a bit out of focus until the END of this project and I did not want to take the bracket back off. You can see the 1/4" diameter hole in the top triangular surface for the LED and the smaller hole on the bottom surface that bolts it to the tach. housing.

The bracket is fabricated from thin aluminum plate.
For better texture match to the rest of the instrument cluster I then sand-blasted the bracket and painted it with black rustoleum "texture" spray paint. (See there's that "anal" streak showing...)



Here is a shot of me starting with the wiring...
The BMW plug is the starter item, it has 3 wires - Ground, +12, and a speed wire that is not used (by me anyway).

Looking at the wires in the motorcycle side of the harness we have:

(1) Brown = ground
(2) Blue/Green = Speed Pulse
(3) Red/White = +12V

I soldered in the leads from the voltage monitor and also a 2nd pair of wires that I will use later when I install my GPS unit. The current draw from the monitor is very low, so I am not concerned about overloading the CAN-Bus electrical system.



The leads from the LED back to the heatsink with the actual electronics in it are about 18" long ... I wish they had been a bit longer as by the time I routed the wires down from the instrument cluster and along the frame of the bike I ran out of wire about here:



What you see there is a temporary tie-wrap that I installed while I considered my options.

The "rib" you see the heat sink attached to is the left side rib behind the side fairing which I removed for easier access to the guts of the bike. I also removed the windscreen to get better access to the instrument cluster.

I ended up sticking the heatshink onto the inside surface of the rib with the double-face tape provided in the kit and then also tie-wraping it to the rib for extra security.

Below you see the finished result - the extra LED lines up nicely with the existing lights and does not look too "home made".





A couple of notes:

1) The provided GPS plug is connected to the CAN-Bus so no fuse is needed... well that's what I understand to be true ;-)

2) The plug stays live for about 60 seconds after the key is turned off, so if you are double-checking your voltages or something remember the wires are live for a bit after the key has been turned off!

3) Note that when the top panel is re-installed that the lighter plug "uses up" pretty much all the space that exists below and to the left of the ignition key, so route your wires accordingly.

4) If your battery is weak at the end of a ride as result of running your gloves and your vest and your GPS and your coffee-cup warmer, beer cooler, or whatever .... you CAN turn off your headlight and let the bike idle for a few minutes with reduced load to top off the battery.

HOW do you turn off the headlight you may ask?

1) Press and hold the cancel-turn-signal button for ~6 seconds (you know 1001, 1002, 1003, .....)

2) Press and hold the right turn signal button until the headlight goes off.

It will stay off until you turn off the bike or move the bike with the engine running.

I'm really pleased with how it came out, I could have been done in 30 to 45 minutes but ... routing the wiring to my personal satisfaction and applying the heat shrink tubing to the soldered connections and .... takes longer if you are a perfectionist, so I think it took me about 2 hours not counting bracket fabrication time.... which as I said was NOT easy due to the complex shape and tight tolerances needed to make it nestle snugly into the "niche" between the tach. & speedo.

Well I'll shut up now.
 

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Discussion Starter · #3 ·
Dan:

Yup, that should work equally well!

I had the GPS plug to install anyway, so "Y-ed" off of that to run GPS and the voltage monitor.

Jim
 

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This looks very nice, Jim. My installation on an F800ST (see http://f800riders.org/forum/showpost.php?p=205393&postcount=17) uses a 12V automotive relay to trigger off the Canbus circuit that powers my GPS. I use the relay to switch the voltage monitor, which gets its voltage measurement directly from the battery. This makes the wiring a little more involved.

My decision not to measure the voltage on the Canbus circuit wasn't to avoid adding an extra load to that circuit (voltmeters usually have very high impedance values, so shouldn't have a significant effect), but rather to avoid measuring a voltage signal that is likely less than the battery voltage due to the slight potential drop arising from the Canbus electronics.

Cheers,
Andreas
 

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Discussion Starter · #6 ·
Warby & Old_Airhead:

Sorry not to reply, for some reason I wasn't getting notified on this thread ... and I started it ;-)

Warby:
Indeed there might be some voltage drop on the CANbus, I had not considered it!

So far within the "resolution" of the LED ;-) I am pleased with how it works. My real objective was to get advance notice of a charging system failure or too much accy. draw so that I would have time to "react" prior to the battery voltage dropping into the "I-can-no-longer-fire-your-injectors-bye-bye" mode ;-

Airhead:
Yeah the bracket is nice as ... well it doesn't look like I just duct-taped it on there... it was a bit tedious to fabricate though...

Jim
 

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Help

Hi. I'm trying to take switched power from the GPS connector (on top of the battery) on my 800GS, to connect my auxiliary HID lights. I can't remember where I read, but they say that connector is rated 5 Amps. I also hear that it takes lots of Amps to start the ballasts. The DDM tunning say their ballasts are "Fully digital, draws less than 6 amps at start up and 3.4 amps at normal operating temperature" (http://www.ddmtuning.com/index.php?p=product&id=101&parent=85 ). Still, I am not sure if the canbus system would allow me. Do I risk anything?
Also, I'm putting HID in the stock light (low beam), and was thinking to go 50W like the original, but I am afraid not to melt the lenses and the housing. Would a 55W HID would create problems? Would a 35W HID give me computer errors?
Anyone knows a good place to mount the fuseblock?
Please help guys. My bike is all disassembled, I have all the parts, but I won't start until I know for sure.

Thanks much.
 

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Discussion Starter · #8 ·
Cula:

I hope you got your problem figured out ....
For some reason I don't get notified when a post is made to an HOW article ... only to a regular forum thread [B)]

I just wanted to post an update to this ...
Originally I wired only the Voltage LED into the GPS circuit and everything worked fine.
As noted there is a ~30 second delay before the GPS circuit goes dead after the bike is turned off.

Later I added a 12V DC to 5V DC converter "brick" (Purchased from Garmin) to allow me to run my Nuvi 500 from the bike - the Nuvi has a 5V mini-USB power connector not a 12V connection (which is what I think the "real" bike GPS units use). Anyway, after adding this I noticed that sometimes the circuit would NOT go dead after 30 seconds, but would stay on.
When I discovered this condition if I turned the ignition on and then back off it would clear, but I didn't like it ... so I have moved the GPS power tap to the battery directly. I just thought I'd pass that on....
 

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Discussion Starter · #9 ·
BTW:
I am happy to send the template for my little LED mounting bracket to anyone that wants it...

I've tried sending it by e-mail but it never seems to print at 100% scale...
so if you want it e-mail me your postal address and I'd be happy to mail you a copy with some comments ...
no charge ... it's the least I can do!

But if I ever break down in your neck of the woods I want space to pitch a tent and a couple of cold beers ok? [;)]
 

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You can mount the ballast under the right fairing, then drill a hole on the headlight cover.
I should inform you though that there are at least two cases of headlight mirror fogging when using HID lights on the F800GS.
 

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Speedometer Trip computer Odometer Tachometer Motor vehicle
So here is my solution for a voltage monitor. I wanted a 12V cigarette lighter type power socket so I fabricated an aluminum plate to attach behind the speedometer and just found these tiny LED voltmeters on Ebay for $3 each, shipped! Font Auto part Fashion accessory Gas Electric blue

The bracket attaches with 3 1/8 pop rivets and a little silicone. The speedo pops off with 3 little clips and I carefully drilled the holes to clear the rubber grommets that the speedo assembly sits in. The aluminum plate is the old one that just held the cig lighter plug I just made a bigger one to also hold the voltmeter.The cig lighter is wired hot to the battery with a fuse and I wired the meter to the switched canbus plug that sits on top of the battery so the meter shuts off a minute or so after the key is switched off.
 

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Discussion Starter · #12 ·
that looks very nice!
$3 for the monitor seems like a great price - is it waterproof?
Do you have a link to the seller per chance?
 

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Yes it is supposed to be waterproof but it is hard to see in sunlight. I just got these 2 weeks ago and I looked on my ebay account and for some reason the seller has been removed from Ebay. Also they were much more expensive, $5 shipped! The sellers name was luckystarthx but like I said all his listings have been removed for some reason??
 

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Discussion Starter · #14 ·
Thanks ... I have the LED style which might be better for me anyway as I'm easily distracted [:D]

but I'll keep an eye out on ebay!
 
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