I just received the following alert from the AMA Safety Committee in
Muncie... I would hope ALL users of Li-Poly batteries give it special
LM AMA 4305
EMERGENCY SAFETY ALERT
Lithium Battery Fires
Lithium batteries are becoming very popular for powering the control and
power systems in our models. This is true because of their very high energy
density (amp-hrs/wt. ratio) compared to NiCads or other batteries. With high
energy comes increased risk in their use. The, principal, risk is FIRE which
can result from improper charging, crash damage, or shorting the batteries.
All vendors of these batteries warn their customers of this danger and
recommend extreme caution in their use. In spite of this many fires have
occurred as a result of the use of Lithium Polymer batteries, resulting in
loss of models, automobiles, and other property. Homes and garages and
workshops have also burned. A lithium battery fire is very hot (several
thousand degrees) and is an excellent initiator for ancillary (resulting)
fires. Fire occurs due to contact between Lithium and oxygen in the air. It
does not need any other source of ignition, or fuel to start, and burns
These batteries must be used in a manner that precludes ancillary fire. The
following is recommended:
Store, and charge, in a fireproof container; never in your model.
Charge in a protected area devoid of combustibles. Always stand watch over
the charging process. Never leave the charging process unattended.
In the event of damage from crashes, etc, carefully remove to a safe place
for at least a half hour to observe. Physically damaged cells could erupt
into flame, and, after sufficient time to ensure safety, should be discarded
in accordance with the instructions which came with the batteries. Never
attempt to charge a cell with physical damage, regardless of how slight.
Always use chargers designed for the specific purpose, preferably having a
fixed setting for your particular pack. Many fires occur in using
selectable/adjustable chargers improperly set. Never attempt to charge
Lithium cells with a charger which is not, specifically, designed for
charging Lithium cells. Never use chargers designed for Nickel Cadmium
Use charging systems that monitor and control the charge state of each cell
in the pack. Unbalanced cells can lead to disaster if it permits overcharge
of a single cell in the pack. If the batteries show any sign of swelling,
discontinue charging, and remove them to a safe place outside as they could
erupt into flames.
Most important: NEVER PLUG IN A BATTERY AND LEAVE IT TO CHARGE UNATTENDED
OVERNIGHT. Serious fires have resulted from this practice.
Do not attempt to make your own battery packs from individual cells.
These batteries CANNOT be handled and charged casually such as has been the
practice for years with other types of batteries. The consequence of this
practice can be very serious resulting in major property damage and/ or
Academy of Model Aeronautics
5161 E Memorial Drive
Muncie, IN 47302
- posted 18 years ago