The Graupner Polaron is a two-port charger
with each port supporting 400 watts. This DC
charger can be purchased with a matching
power supply. Its form factor doesn’t take up
much space on the bench.
Designed by Mark Wood, the LipoSack was released in 2006 as a means
to charge, store, and transport LiPo batteries.
Photos by MA staff
let the charger
do all of the
To get the
1C, even if the
battery states it
can be charged
at 3C or even
at a higher rate
life of a battery
will affect the
number of cycles
you are able to
get from the
rate as similar
To get your
shipping has a
money. The same goes for your batteries. Charging them at
higher than 1C will allow the charge process to complete
faster; however, it is at the cost of reducing the number
of cycles that the battery will provide throughout its
Safely Charging Batteries
The two most common instances of having a LiPo battery
vent or catch fire are arguably during the charging process or
resulting from a crash. When charging the battery, you can
further protect yourself by never charging batteries unattended,
charging them in an isolated area away from flammable
materials, and using some type of device or container that will
encompass the flames if a battery were to vent.
Commercially available products include the LiPo Sack,
LiPo Bunker, an ammunition can, or concrete blocks. Any
device that you use should contain the flames while allowing
the gases to vent. In the case of the ammunition can, you
can drill small holes in the top to allow venting. If the LiPo
is unable to vent, it might cause an explosion.
It is important to have a smoke detector, sand, and fire
extinguisher nearby. The detector will alert you if a pack
begins to vent. The sand should be used to extinguish a LiPo
fire and the extinguisher is to put out any other material
that might ignite because of the fire.
Household fire extinguishers are not rated for use on a
LiPo fire. Class D fire extinguishers can be used for a LiPo
battery fire, but they are costly.
Advancements in LiPo batteries have made it possible
to power aircraft from ultra-micro size to Giant Scale
models. Having a basic understanding of the batteries and
the chargers used will go a long way toward ensuring the
safe use of LiPo technology so you can benefit from lighter
batteries and longer flight times.
I want to thank David Buxton, Tony Stillman, Thunder Power
RC, and Hitec USA for their assistance with this article.
LiPo Battery Basics (Part 1)
LiPo Battery Basics (Part 2)
(765) 287-1256, ext. 230
Thunder Power RC
48 Model Aviation SEP TEMBER 2015 www.ModelAviation.com