Hardware Reference
In-Depth Information
(Source: Image courtesy of
adafruit.com
)
Figure 9.15
Project materials.
Batteries and Power
Powering DIY wearable electronics projects is one of the more challenging aspects of this
new field in emerging tech. How do you choose the right power source? Will it be safe?
Beginners need clear instructions about which batteries to use, how to use them safely, and
why. Alkaline battery packs with hard shells are the safest and most straightforward option
(and can hold rechargeable NiMH batteries, too), but they can be clunky. Three AAA bat-
teries are too bulky for a hat, for example.
Lithium ion polymer rechargeable cells are power-dense, lightweight options, come in
many shapes and sizes, and require a special charger to fill them up. Some are small
enough to wear on earrings or other jewelry (
Figure 9.16
). Lithium cells are more delicate
than alkaline battery packs and for this reason more care and attention are needed to pre-
vent damage. You should never bend, puncture, crush, or otherwise abuse these batteries.
Also, they don't come in a protective hard shell. Lithium batteries can get hot during char-
ging, so they should be charged off of fabric or the body to prevent possible burns or fires.
