You Gotta’ Keep ‘Em Separated
What do you use to charge your mobile phone or other gadget when you’re out tearing up the highways?
I’ll bet that unless you’re riding a ‘Wing, BMW tourer or some other such (ahem) refined piece of machinery, you probably have to find some truck-stop or hotel where you can plug said gadget into the nearest available power-point.
This is all well and good, but what happens you’re caught unawares. Say you’re GPS battery expires, and you are hopelessly lost in the Simpson Desert or some other similar desolate place.
OK that’s an exaggeration, but you get my point…
I thought about this a while back, and decided that some sort of charging receptacle would be a handy addition to Bluey. So I went on the hunt for a USB charge point I could mount to Blueys’ ‘bars. After much Googling I came up with the TAPP™ 2.1Amp Weatherproof USB Power Port from 3BR Powersports
The Power Port allows me to put my phone or other gadget in my tank bag and charge while I’m riding. Any excess charge cable can be poked into the bag and it doesn’t interfere with steering in any way.
Out of the box you can connect the black lead of the Power Port to the negative terminal of your battery and the red (fused) lead to the positive terminal of your battery and viola! That’s it, you can charge gadgets to your heart’s content.
Now, I don’t know about you, but connecting something directly to the battery in an “always on” state, doesn’t sit well with me. Sure there’s a fuse in line, but what happens if gremlins get in there and decide to deflate your battery, or worse, create sparkle-arkles ?
So I decided to install a separate circuit for my accessories. This separate circuit does two things:
- The circuit is turned on and off with the ignition.
- It keeps any aftermarket accessories away from the main wiring loom preventing OEM smoke mixing with accessories smoke.
Now, I’m not even close to being as talented as the bloke that pulls the wires for an electrician. So if you decide to have a crack at replicating what I have done here, and manufacturers smoke escapes from some hard-to-get component on your bike; you’re on your own.
Likewise, getting said manufacturers smoke back in to what ever component it escaped from is on you as well. If you have any doubts about your abilities when it comes to working on your bike, electrical or otherwise, please find someone to help you.
Better still get them to point and explain what needs to be done, and you do it… it’s best way to learn.
So let’s get started. First of all you’ll need some bits and pieces:
- 1 off Weatherproof USB Power Port, or other gadget you want to install.
- 1m (3′) 25 Amp DC Auto Power Cable – Black (or white in my case)
- 1m (3′) 25 Amp DC Auto Power Cable – Red
- 1 off Automotive Fused Relay – SPST 30A
- 1 pack – Fully Insulated Female Spade (for connecting to the relay terminals)
- 1 off 30 Amp 12-way Screw Terminal Strip
- 1 pack eyelets
- Heat shrink or electrical tape
- Cable ties
Allow me to walk you through the schematic above.
- Connect terminal 87 to the positive side of you battery, use an eyelet to make the connection, don’t just wrap the wire around the bolt. Note that if you use the relay that I have nominated above, you will not need the inline fuse shown in the schematic. Try and keep the lead as short as possible and away from moving parts. I’d recommend you double insulate this wire with some heat shrink.
- Using and eyelet, connect terminal 86 directly to the chassis of your bike. Connect it to any nearby bolt or screw. As long as it’s metal you should have a good connection back to the negative terminal of your battery. Again try to keep the lead as short as possible. Double insulating is not necessary.
- Keeping the wire as short as possible, loop some red wire between each terminal screw on one side of the terminal block, then connect the last terminal back to pin 30 on your relay. This is now your distribution block.
- Pin 85 on the relay can be connected to the positive side of your tail light, number plate light or any other item that is switched with the ignition. Do not use a splice connector when doing this, soldering the wires together is by far a stronger joint. Don’t forget to insulate any bare wires with heat shrink or electrical tape.
Using this method, the OEM wiring loom is not changed in any way, other than splicing into the trigger line. The trigger line supplies a very small amount of current to trigger the relay, maybe 1/4 amp (250 ma) at most.
When the relay triggers, it will draw current from the battery and provide up to a total of 30 amps (or whatever your fuse and relay are rated at) to your accessories. This could include driving lights, horns, GPS etc. As long as the total current rating for the relay and fuse is not exceeded, your circuit will happily power your accessories without affecting the OEM circuit in any way.
Don’t forget, bike batteries are tiny compared to a cars, so don’t go trying to power your camp fridge from your little circuit 😉
Note that when connecting your accessories, you only need to connect the positive lead back to the unused side of the distribution block. The negative lead can be connected to any nearby bolt or screw on your chassis. The circuit will be completed via the chassis.
I recommend running an additional fuse between your gadget and the positive side of the terminal block for added protection against any short-circuit. This will also make it easier to trace a fault. If the small (say 2 amp) inline fuse blows, the problem lies between the terminal block and the gadget. If the larger 30 amp fuse blows on the relay, the problem is between the distribution block and the battery.
My distribution block is located under one of the side covers, the relay is under the seat and sits between the ECU and the chassis rail. A couple of cable ties were added after the photo above was taken to hold it all in place .
I know there are commercially made distribution block and relay devices available, but they cost a small fortune. Done correctly and with some care, this method is every bit as good and much cheaper.
If you don’t want to buy a dedicated USB charge point like I did, you can buy a marine grade 12 volt accessory point (we called them in-car cigarette lighters in the old days) and use your standard phone car charger instead. The only problem with this, is it’s not water proof when in use.
I have a ciggy lighter on my bike as well, it’s handy for when I need to inflate a tyre or plug-in a lead light for on the fly repairs on the side of the road.