Li-Po Safety

Charging of Lithium-Polymer batteries
Most people would be aware of Lithium-Polymer batteries and the increased freedom they have given to those flyers inclined towards electric flight. The batteries are smaller and lighter than their equivalent counterpart and have a lower internal resistance giving the ability to draw a much greater number of amps. A quick search on the web will reveal many fellow flyers touting the benefits of Li-Po batteries.

However, as with all things good,  there is always a downside (who came up with that law?). In this case it is not so much as a downside but rather some important safety items to keep in mind.

Li-Po's posses different characteristics to other re-chargeable batteries and as such they should be handled in their own way. The major point to note is recharging. Li-Po's require a very different charge method than other types of batteries, therefore it is imperative that a charger specifically designed as a Li-Po charger be used. Use of other chargers can result in a fire. Some Li-Po chargers also have a manual setting for the battery cell count, if yours does then you must make sure that it is set correctly before you attempt to charge your Li-Po and do not charge the battery packs in series, charge each one individually.

The attached photos, taken locally, show what can happen if Li-Po's are charged incorrectly.

It is always a good idea not to leave charging Li-Po's unattended. If you notice the batteries start to balloon or swell discontinue the charging process immediately and keep an eye on the battery in a safe place for at least 15 mins. Leaking chemicals can react with the air and cause a fire. For some added safety use a fire container, like a steel bucket, containing a layer of sand and place the charging Li-Po on the sand. If you notice ballooning or any other unusual behaviour you can carry the whole unit outside without causing any damage to property.

If you follow basic safety practices and charge your Li-Po's correctly then they will provide you will all the fun of great flying and extra power that Li-Po's are capable of delivering. But remember to always read the safety information contained with your batteries and charger.

Great flying.

Adam