amp mobile power source whose battery is recharged when-
ever it finds 6-25 volts on the rails, in any form, DC or DCC,
even AC! It will recharge and protect the LiPo battery simulta-
neously. Later, we’ll look at another variation.
Not everyone may be familiar with LiPo batteries, but they
are actually quite common. They power many cell phones and
tablets. They are light in weight compared to many other bat-
tery types. LiPo batteries have very high energy density. That
is, they pack a great deal of electrochemical power in a very
small volume. As such, if shorted out they can generate a great
deal of heat in a short time, and can even explode and catch
fire. Therefore, protection circuitry is essential for safe use.
Damaged LiPo batteries should not be used, and should be
disposed of properly and safely. When fully discharged for dis-
posal they are not a toxic hazard. Over-charging and over-dis-
charging damages a LiPo battery.
All these concerns for charging and use are handled by a small,
low-cost ($3.99) battery manager board. This board is available
4
4. Basic power block components.
Battery-powered models - 3
MRH-Nov 2014