This is part 3 of a series of articles in which I try to put together a covert Diy Car Tracker on the cheap. If you want to know how I constructed it then take a look at part 1 and part 2.

This is the part when I can relax a little, when I set out on this project I had a number of major worries.

• Would my cheap Car Tracker get a GPS lock hidden in my car?
• Will the GPS quality be good enough?
• Am I be able to find a constant 12v supply?
• Would I drain my battery?

Worry #1: Would my cheap phone get GPS lock hidden in my car?

It actually works really well. The Pay as you Track App is pretty clever. It has some neat features which mean that once you’ve installed the Pay as you Track App and registered your phone you don’t need to go back to it.

Firstly, the Pay as you Track App auto restarts when the phone reboots. This means that even if your phone restarts or runs out of power as soon as it starts up again the Pay as you Track App will fire up and you’ll be up and tracking again.

Secondly, it automatically detects when the vehicle moves, this means you don’t have to tell it to start tracking it just does it.

Lastly, if you go out of SIM coverage the Pay as you Track App will buffer all your positions and send them on when it next has a data connection. If you happen to not really want live data then you don’t need to even put a Sim in the phone. Just set up the wireless access details and the phone will download it’s positions next time it gets a wifi connection.

Worry #2: Would the GPS quality be good enough?

Ok, lets be honest, the GPS in cheaper phones can be pretty poor. However, I was actually pleasantly surprised, GPS tracking was pretty excellent. The Pay as you Track App records a position every 30 seconds unless you turn. So if you driving around a town you actually get a lot more positions logged than once every 30 seconds. Here’s an image showing part of my journey into Leeds at the weekend. All in all, pretty good for £10!

Worry #3: Would I be able to find a constant 12v supply?

This was definitely the hardest bit of the whole project. Locating a suitable source required some research on the internet and a bit of trial and error. However, once I had located a source fitting the tracker was pretty easy.

Worry #4: Will I drain my battery?

I need to be realistic about this. I drive a large diesel Volvo XC90 with an enormous battery which I use almost every day. So in my case, I don’t think I’m going to have a problem. I need to be clear about this though, there is a big difference between my phone tracker and a wired or plug-in tracker. My tracker draws power from the battery all the time. A purpose-built tracking device will have an ultra low power mode and draw a lot less current when the vehicle is not moving.

I hooked up my multimeter to my DIY car tracker to see what the current draw was. The phone was fully charged at this point as it had been in my vehicle for a few days.

Current (mA, screen off, GPS on, wifi off) ~ 80mA. My XC90 battery is 80Ah so if there were no other drain that would be 41 days.

If you are interested in more details please see part 1 and part 2