Data Hacking

Chapter 3 — Power Hacks
But what about when you are on the move? How can you supply power to your GPS receiver
when walking, hiking, or geocaching?
Carrying Your Own 12-Volt Power Supply
One thing that you can do is carry your own 12-volt power supply around with you. No, this
doesn’t mean having to lug a heavy car battery that can spill sulphuric acid all over the place!
Other options are available to you.
One thing you can do is buy a portable lead-acid battery designed for large flashlights. They
contain a cigarette lighter socket and often come with a case and belt loops. These batteries
usually have fuses, as shown in Figure 3-5. They come in a variety of sizes; generally, the
larger the battery the longer it lasts. The downside, however, is that the larger the battery,
the heavier the battery.
These packs will give you hours of additional battery time and the batteries can be recharged
when you get back to your vehicle by plugging them into the cigarette socket. Charging back
at base is via a charger that plugs into a mains power outlet.
However, you might have handy batteries suitable for this job lying about. If you have an old
PC uninterruptible power supply (UPS) unit lying around (the kind of thing that any selfrespecting
geek would have!), these typically contain a battery similar to the battery packs that
you can buy for flashlights, as shown in Figure 3-6.
FIGURE 3-5: A fused 12-volt lead-acid battery
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