Data Hacking

276 Part IV — Playtime
To keep the PDA going, I use a combination of an expansion battery pack that gives me a few
extra hours, a car cord, and an external battery pack that will power or charge the iPAQ from
four AA batteries (see Figure 11-21). I find that the pack is an ideal way to carry a few spare
batteries for the GPS.
FIGURE 11-21: iPAQ external battery pack
Another option to charge an iPAQ while on the move is a solar charger, as shown in Figure 11-22.
If you have a car cord for your iPAQ, then using a solar charger such as the Silva Battery Saver,
you can, given some sunlight, plug the car cord into it and charge the internal iPAQ battery.
When using solar panel chargers, take care to protect the panels from damage. While they are
quite robust, they aren’t indestructible.
You could also use a portable lead-acid battery (shown in Figure 11-23) and a socket splitter,
which would enable you to power both the GPS and your PDA. The drain on a lead-acid battery
will be a lot less than it would be for other kinds of batteries and you can charge up the battery
in your vehicle. The main disadvantage of using such a battery is the weight associated with it.
To help others, some geocachers put spare batteries into geocaches as swaps. These are really
good swap items and could really get someone out of a jam if their batteries are low and they
need to navigate their way back to the car. Putting batteries in a cache is referred to in geocaching
parlance as “leaving GPS food”!