TVNZ program FSI covered a fire that seriously damaged an automotive service garage.

Before leaving for the night the owner and a friend were flying model helicopters using Lipo batteries. One or more batteries was left on charge on a work bench overnight.

The investigation concluded that the Lipo battery was the cause of the fire. Having used and abused a lot of Lipo batteries I suspect there may be more to it. If treated correctly these batteries are very reliable. I’ve seriously damaged 3 or 4 and never had any smoke or fire; just a loss of rated capacity. I have had one battery swell up during charging but that was due to the charger being incorrectly set.

There a few points not covered in the tv program although they may have been considered during the investigation:

1. Was the power supply a suitable regulated DC power supply or was it a type of 12V car battery charger? If a car battery charger, it could have supplied a voltage or waveform that upset or damaged the smart charger that was connected to the Lipo battery.

2. Was the smart charger set correctly for the Lipo being charged? If not, the charge current could have been too much for the Lipo.

Otherwise, the outcome was reasonable. It was disappointing that the correct use of these batteries was not covered at the end of the program. I guess these programs are meant to be spectacular and exciting rather than helpful and informative.

Leaving the blame with the battery may well have been incorrect.

Lipo batteries do need to be treated correctly during use and charging. They should be stored and charged in a safe (fire proof) location. They should not be charged unattended.