DIY: iPhone 4S as $3 a month LoJack

[nchopp]

So this works for any vehicle, the only differences may be where you decide to locate the device.

Goal: GPS locator with pay as you go data service on a large cell network

Carrier: There are many non-contract carriers, but the trick is finding one that has a pay as you go plan with long or no expiration. I looked at a lot of options, but settled on Page Plus Cellular. They offer a $10 Pay As You Go plan that gives you 100 minutes or 100mb of data that expires after 120 days. They use Verizon's network, so they're CDMA.

Device: Once I settled on Page Plus, I had to obtain a 3g smartphone, as the Pay As You Go plans only support 3g devices. While I'm typically an Android guy, the iPhone 4S is the best choice compared to pretty much any of the 3g Android phones. It still runs iOS 7.1.2, which lets me use the app I decided on. I snagged an 8gb iPhone 4S for $55 on eBay in pretty much mint condition.

App: Device Locator. $2.99, allows you to set the interval that it updates the https website, including different frequencies, or just when it switches cell towers. This uses a very minimal amount of data, since all it's transmitting is location and battery percentage. Also offers the ability to remotely trigger the camera.

Electrical: My M6 has a cigarette lighter outlet in the front passenger foot well, very close to the glove compartment. I ran a Micro USB cable off an Anker 2.1a USB charger in to the glove box, and I'm using a Limefuel 20,000mah USB battery pack with pass through charging as a power buffer. This both is and isn't working the way I intended. When I turn the car on, the Limefuel turns on and begins charging the iPhone. The problem is, once the iPhone hits 100%, the Limefuel shuts off, and doesn't begin charging the iPhone again until the vehicle is turned on. I'm thinking about getting a casebattery for the iPhone, as that will add an additional buffer. I'm going to give it a week or two first, and see how it works. So far, the worst I've had is the battery hits 95%, but I only got it running Thursday. I also made sure I disabled everything not strictly necessary - background app refresh, updates, etc. I did leave WiFi enabled, so it's using that when it's in the garage. Article for maximizing battery life: http://www.zdnet.com/pictures/how-to-im ... ife-ios-8/





Products used:
Verizon iPhone 4S (eBay)
Cell Service:: https://www.pagepluscellular.com/plans/10-standard-pin/
USB Battery Pack: Limefuel LP200X 20,000mah USB Battery Pack http://www.amazon.com/gp/product/B00OHZ ... K718EJ8QC0
BatteryCase I'm considering: http://www.amazon.com/gp/product/B00409 ... 8P1OMW3VD1
USB Car Charger: Anker 24w 4.8a Car Charger http://www.amazon.com/Anker-Charger-Pow ... ar+charger
App: Device Locator: https://itunes.apple.com/us/app/device- ... 95093?mt=8

Article for maximizing battery life: http://www.zdnet.com/pictures/how-to-im ... ife-ios-8/

[nchopp]

Update: Working flawlessly. She pulls about $0.5 to $0.11 of data daily. The battery seems to work out like this:

On starting the vehicle, the Limefuel battery pack turns on. If the iPhone is already charged, it turns off immediately. If it is not charged, it charges the iPhone to 100%, and then turns off. So far, at about 0200-0300 the iPhone dips to 95%. When I start the vehicle again (0400 on weekdays, typically much later on weekends), the iPhone charges back up.

For a daily driver, this is perfect. For a vehicle that doesn't run as much, an iPhone battery case may be a good investment. That being said, the thing is absolutely SIPPING battery. You could stretch it out even longer by setting it only to update on cell phone tower switch.

[nchopp]

Three months later, still working great. The battery has died once, and that's while she was at the dealership for the better part of a month and didn't get started for about two weeks. I've had to recharge the PagePlus account once, for an average operating cost of $0.11 a day.