When I use my Mio C220 GPS on my bike the battery doesn’t last long. This sucks. Especially for those long trips. Also, It would be cool if I could charge my cell phone and mp3 player on the go.
Add a powered USB port, hooked to the battery, for everlasting power.
The dirty details:
First of all, you’ll need an 7805 voltage regulator A.K.A. LM7805, a diode, a fuse, some cable, and a female Type-A USB port.
While you *could* wire up everything on your own, there’s no point doing so.
For about 1 Euro you can get a USB car charger, from ebay. (Postage included)
It would cost you more to get the individual parts, plus you would have to find some sort of case to protect them. For 1 euro you get everything you need. Sweet deal.
Carefully dismantle the car charger.
If it includes a fuse, you’re lucky. Mine didn’t. It’s fifty-fifty. Some have a fuse, some haven’t.
Although you could get away without using a fuse, I highly recommend it. We don’t want to burn down our beloved bikes, do we?
Get rid of the spring either by cutting it, or de-soldering it. This is the positive output of the circuit.
Also throw away the metal contacts. We don’t need those either. Just try to keep the little black cable intact.
It’s easier to solder on the cable instead on the PCB itself. Black equals ground, or negative.
This is where I connected my 2 amps fuse. I’m not sure whether you’re supposed to wire it on the positive or the negative lead, but I don’t think it matters much.
If you have a multimeter it’s a good idea to test the connections to make sure you’ve soldered everything correctly.
Now connect positive to positive, and ground to ground on your battery screws, and wait for the fireworks. (Just kidding). Just take extra care not to connect them the other way around, or the voltage regulator will get red-hot and start melting everything.
Now wire a mini-USB cable that runs from the battery, through the bike’s frame, to the handlebar.
This way you can charge your GPS and use at the same time.
And if I ever need to charge something under the saddle, I can always unplug the handlebar cable and plug any USB charger under the saddle.
The only problem with this configuration is energy waste. All the excess voltage is converted into heat. This isn’t just wasteful, it’s also a small flaw: When the engine is running, the voltage on the battery gets up to 14V, so the regulator has to drop it to 5V which is quite a drop. The specs for 7805 specify that it can take as input as much as 35V with a heatsink. In this case I’m not using one, plus everything is encased, and under the seat. Depending on your motorcycle, things might get very hot.
My Aprilia has the engine air-intake under the seat so I’m hoping to get some air-stream on it that will help cool it down.
My next upgrade will be to perforate the plastic so that it “breaths” better.
First, you’ll need a cheap generic motorcycle holder.
China is again the way to go. So fire-up ebay, and search for a motorcycle holder. Any device will do, as we only use the handle-bar ring, and the plastic platform.
I found a motorcycle holder for the Samsung i900 Omnia for just £2.75 including P&P.
Next step is to clip all the protruding plastic bits that hold the Samsung in place, until you’re left with a flat plastic platform.
I’m sorry, I don’t have any before pics.
Now glue some neodymium magnets (AKA rare-earth magnets) on the platform, and the equivalent amount of magnets on the GPS it self.
I glued them with hot-glue and up to now it holds great. You can use other glues as well, but my guess is that they will start dissolving under the blazing summer-sun. Epoxy would work even better if you have it.
Just make sure to reverse the polarity so that they actually pull each other instead of pushing.
We don’t want that, unless you’re trying to build a self-floating GPS.
It won’t work.
The mod works fine even with just 4 magnets. I’ve used 8 just to be sure. The magnetic attraction is so strong that it’s very hard to pull them apart even by pulling with both hands. There’s no way to accidental lose it.
I bought a second hand Mio c220 GPS to tinker with it.
While trying to hack it, I also flirt with the idea of replacing its internal battery.
Since I bought it for 20 euros, I don’t care much if I break it, so I took the plunge:
I disassembled it to see what’s inside. Here goes.
Before you start unscrewing stuff, take a mental note of the power button. Once you remove the rear cover, the button will go flying and you will have to figure-out which way is the right way to put it back in.
Also, performing an open-heart operation on your loved GPS is not a risk-free matter. I cannot be held responsible for any damaged units. Proceed at your own risk.
Right. Were was I? Go on and unscrew the 4 screws on the back. Then you have to pry it open. Use a flat screwdriver and be careful not to mark the plastic casing.
Once you separate the casing into 2 pieces, carefully disconnect the black and white cables that connect the speaker to the PCB. This will give us some more “breathing” space for our tinkering.
You can buy a direct replacement for about £7.5 or if you’re a real cheapskate like me you can buy a cell-phone or camera battery which are cheaper.
I haven’t tried this one yet, but it appears that the following batteries have very similar dimensions and should fit within the casing.
The only downfall is that you will have to cut the cable off the original battery and solder it on the new battery contacts. Shouldn’t be that difficult. Just make sure that you keep the soldering process short as batteries tend to explode on your face if you overheat them with a soldering iron. And they overheat fast.
I’ll first let the battery die completely and then I’ll buy a new one, so I’ll let you know how that goes.