Battery saver for dual headlight setups

[GTPAddict]

I got stuck in traffic a few weeks ago, the kind where you don't really move. Well, after moving about a mile in 10 minutes, I accidently stalled my bike. As luck would have it the battery was drained to the point it would not start the engine, so I had to pop start it.

This happened once before, while taking my MSF course. The first half of the class was basically idling around in a parking lot, and with both headlights on, by lunch the battery was too weak to start the engine (again, it pop started just fine) I disconnected the second headlight, rode around a while at lunch, and the bike was fine the rest of the day.

So (after that long ass story) I decided to do something so this wouldn't happen again. After searching, I found that a lot of people install a separate switch to turn off the second low beam for just such occasions. I thought I could do one better. I designed a circuit and programmed a PIC to turn off the second headlight if the battery voltage drops below a certain level (testing 11.5 volts now) for over 2.5 minutes, and turns it back on if it stays over a certain level (testing 12.2 volts) for 2.5 minutes. I may also play with the delays, but I'm still in the development stage. Tonight I finished building the circuit and tested everything on a breadboard, tomorrow I plan on soldering everything together, and by the weekend it will be installed.

Installing will be super easy, just 3 wires (ground, 12 volts from dimmer switch (connected to right low beam headlight now), and 12 volts to the headlight). Everything will work as it does now since the device will get it's power from the wire currently going to the headlight, so when high beams are selected there is no power to the device. I'm using a NC relay, so in case something happened the headlight would default to being on. When the conditions are right, the relay is turned on and the contacts are opened.

Anyway, I was looking at maybe having a circuit board made (I'm using a radio shack generic board now) and was wondering if this is something anyone else may be interested in. If I do decide to have a board made, I believe the minimum order for most of the places I looked in to is 20-25 boards. If this is going to be just for me, I probably won't do this, but I thought I'd ask here and see if there was any interest.

If anyone want's more info, let me know. Looks like the parts to build it will be around $30 or so (not including an enclosure), then it would have to be assembled. I may be willing to do this, but I haven't really thought too much about it.


BTW, here's a thread that really got me thinking about doing this -> http://www.600riders.com/forum/garage-mechanical-help/32324-charging-system.html

 

[motojoe122]

I have not had a problem with the battery so I picked the last option on the poll. But, I do think this is a great idea and will look into it more.

 

[trepetti]

I just installed the BD43 mod on my 05 during this off season. It is the original battery, and I was considering the threat of having a bad battery year. I had not thought about the extra draw from the 2nd headlight.

So this sounds like an interesting idea. Keep me posted. I'd be interested in doing some testing if you need.

 

[dpaul007]

I don't have the dual headlight mod, but I voted that it would depend on price, as that is what I would vote if I had it done.

 

[Motogiro]

On the Motogiro Universal Headlamp relay you can just add a diode in the relay control line and with a small positive 12 volt signal it will activate the relay and unload the low beam. With my relay you would not need an extra relay to control the higher current headlamp.

If you build this low voltage detection circuit build it with a B+ out to activate the relay.

Ultimately the FZ6 charging system, even though pretty minimal is designed to handle having both headlamps on. If you have a problem with a weak battery or charging system and you're doing a lot of idling in traffic, a stall can translate to a non start.

I do like this idea!

 

[mave2911]

Sounds like a great idea - whilst it hasn't happened to me, when stuck in traffic and the like, it is a consideration that the dual-headlight is drawing more power than the bike is making at idle.

As I live over the pond, I'd be very interested in seeing a schematic, as it'll probably be easier for me to make it myself, than have to pay for shipping and wait two weeks.

Let me know how you go!

Cheers,
Rick

 

[Cloggy]

As I use heated grips, and ride through the winter I haven't carried out the dual headlight mod yet.

I've always been worried that in cold temperatures (when the battery is not at it's best) and with heated grips on the extra headlight might be the proverbial "straw that broke the camels back".

I've had my bike since 2007 and the battery is still going strong :thumbup:.

I would be interested to see how this develops, and like mave would be interested in seeing the schematics. although I don't think I'll be ordering from America

Great idea :thumbup:

 

[4drfocus]

I might be intersted, I'll be installing dual bi-xenon projectors on the streetfighter next month, I'm running l.e.d turn signals and tail light, so well see......

 

[GTPAddict]

I created the schematic in Visio 2010, so for those who don't have it, here's a viewer...

Download Visio 2010: Visio Viewer from Official Microsoft Download Center

And a copy of the schematic can be found here (couldn't add as attachment)

http://theblattners.com/downloads/FZ6HeadlightPICDiagram.vsd

 

[Motogiro]

I created the schematic in Visio 2010, so for those who don't have it, here's a viewer...

Download Visio 2010: Visio Viewer from Official Microsoft Download Center

And a copy of the schematic can be found here (couldn't add as attachment)

http://theblattners.com/downloads/FZ6HeadlightPICDiagram.vsd

Can you print your file to a PDF format and up load the PDF? I tried the MS Visio and it is like installing malware! LOL! Or any Acad type file would be good.

 

[Cloggy]

I created the schematic in Visio 2010, so for those who don't have it, here's a viewer...

Download Visio 2010: Visio Viewer from Official Microsoft Download Center

And a copy of the schematic can be found here (couldn't add as attachment)

http://theblattners.com/downloads/FZ6HeadlightPICDiagram.vsd

Thanks for this I'll take a look later :thumbup:

Can you print your file to a PDF format and up load the PDF? I tried the MS Visio and it is like installing malware! LOL! Or any Acad type file would be good.

Here is the PDF version Cliff (you have to click on the image to open the larger picture)

View attachment 47200

 

[GTPAddict]

Here's the whole thing in PDF format. Sorry about that, I didn't think about saving it in a more universal format :spank:

 

[FB400]

I want one. Had my battery go dead enough to require a push start last fall. (battery tests healthy and was only 1.5 years old.) Spent about 30 minutes in ridiculously heavy traffic then normal riding for another 20 minutes. when I stopped the bike I could not start it again. totally took me by suprise. it sucked

Had a question though.. running dual morimoto projector HID powered by 55 watt ballasts.. how would turning off/on 1 projector work? Would my HID system be upset?

 

[Motogiro]

I think this is a great idea for more reasons than just this app. The PIC 12f675 is a powerful little tool!

On the relay coil being driven by 2n3904: You might want to add a diode across the relay coil for protection. See attached for polarity: This will help to reduce inductive coil voltages/noise that you don't want the switching transistor and the red diode exposed to.

 

[FIZZER6]

Dual 35W HID projector retrofit FTW! I have 3X as much light output as stock and I don't pull any more watts then a single H4 halogen bulb! If you are going to be stuck in traffic a lot maybe you need to set your idle up to 1400 rpms?

 

[Motogiro]

I want one. Had my battery go dead enough to require a push start last fall. (battery tests healthy and was only 1.5 years old.) Spent about 30 minutes in ridiculously heavy traffic then normal riding for another 20 minutes. when I stopped the bike I could not start it again. totally took me by suprise. it sucked

Had a question though.. running dual morimoto projector HID powered by 55 watt ballasts.. how would turning off/on 1 projector work? Would my HID system be upset?

It would work the same way. You would just interrupt the HID you want to take offline to save power. This would be done at the 12 volt positive line feeding the HID transformer.

 

[FinalImpact]

GT - Great idea!
If I were to add a suggestion to your design; I would add this; an indicator light that tells when ones FAN is active. This will raise the awareness and hopefully make some people think and check it more often before the "pebble syndrome" takes its life! I know these are not directly related, but if you're running some warning indicators up there - give it some thought. Also, I personally would opt for yamaha relay over a RS part and the diode as recommended by Cliff.


Thanks and Good luck!

 

[GTPAddict]

Thanks for the suggestion, will definitely add the diode. The relay I was originally going to use had a diode (GM PN 12077866), I forgot to check if there was a diode on this one. The reason for using this relay was size, mounting, and convenience. The relay is soldered to the board, so using one that was easy to mount was the main reason.

I had also thought about wiring up the relay differently. As the diagram is now, the coil and one of the contact get's it power from the wire currently going to the second low beam light. I had thought about isolating the relay contacts from the rest of the circuit by running a separate power wire from the battery for the low voltage circuit and just having the wire currently going to the headlight only go to the relay. The reason for not going that route was simplicity. That and you could always reset the PIC by turning the bright light on for a second. The devise only pulls about 65mA when the relay is energized (turning the headlight off).

 

[GTPAddict]

Finished the board and programming today and partially installed it on the bike (it's in my tank bag until I verify everything). I had to make a small change, but it was probably for the best. I ended up isolating the relay, so I have 2 wires for the headlight (one from the dimmer switch, the other to the headlight) and 2 wires to the battery (12+ & ground). I'm not too worried about running the battery down since it only pulls about 1 mA when the relay is not on and 62 mA when it is, but I may change this later anyway. right now i have it plugged in to my battery tender plug. I haven't hooked up the headlight through the relay yet as I want to watch it for a few days first to get an idea of how it's gonna act. I will end up mounting it in the inner faring, so I won't be able to see it then very easily.

BTW, I also added another wire that is not hooked up to anything on my bike. This wire comes from the NO contact on the relay, so it can be wired up to either supply power or remove it. It could supply ground just as easily since the contact are isolated now.

Here's a new schematic, a simple program flow diagram, and some pictures.

Green light comes on at 12.4 volts (this is the voltage OK switch point)
Yellow light comes on at 11.6 volts (Low battery switch point)
Between 11.7 and 12.3 nothing is changed - no lights are on, no counters are reset or decreased, light is not turned on or off.

When the yellow light is on for 2 1/2 minutes without interruption, the relay is turned on. When the green light is on for 2 1/2 minutes without interruption, the relay is turned off. Anytime voltage rises above 11.6 volts, the counter is reset.

 

[Motogiro]

Finished the board and programming today and partially installed it on the bike (it's in my tank bag until I verify everything). I had to make a small change, but it was probably for the best. I ended up isolating the relay, so I have 2 wires for the headlight (one from the dimmer switch, the other to the headlight) and 2 wires to the battery (12+ & ground). I'm not too worried about running the battery down since it only pulls about 1 mA when the relay is not on and 62 mA when it is, but I may change this later anyway. right now i have it plugged in to my battery tender plug. I haven't hooked up the headlight through the relay yet as I want to watch it for a few days first to get an idea of how it's gonna act. I will end up mounting it in the inner faring, so I won't be able to see it then very easily.

BTW, I also added another wire that is not hooked up to anything on my bike. This wire comes from the NO contact on the relay, so it can be wired up to either supply power or remove it. It could supply ground just as easily since the contact are isolated now.

Here's a new schematic, a simple program flow diagram, and some pictures.

Green light comes on at 12.4 volts (this is the voltage OK switch point)
Yellow light comes on at 11.6 volts (Low battery switch point)
Between 11.7 and 12.3 nothing is changed - no lights are on, no counters are reset or decreased, light is not turned on or off.

When the yellow light is on for 2 1/2 minutes without interruption, the relay is turned on. When the green light is on for 2 1/2 minutes without interruption, the relay is turned off. Anytime voltage rises above 11.6 volts, the counter is reset.

Excellent! I like the added output for other types of control. Grips or accessory relays could also be unloaded from the system. Great job!