model yachting Australia - including d'12metre radio yacht forums

Okay folks, many of you would by now have heard that there are battery packs, that can provide maximum amps, until they are nearly exhausted.

These battery packs, are typically Li-Po (Lithium Polymer) batteries.

They offer huge advantages, in that they are of much lighter weight than equivalent power NiMH battery packs, and that they tend to offer a more constant supply of power over the charge period. But there is also a danger, that by using LiPo Packs rated at 7.4 volts or more, you will stand the chance of dramatically reducing the life of your servo's or even destroying them, and/or, your receiver.

But that greater power may create one additional problem. Using LiPo battery packs also brings with it, a danger, that was never previously there, with NiCad or NiMh batteries, in that if you keep discharging the Li-Po beyond its storage volt value, it is more likely than not, that this battery pack WILL catch fire, and probably destroy your model. 

There are ways to minimise these dangers.

If you use Hitec 2.4G transmitters and Hitec's Optima series of receivers, you can program your transmitter to warn you when your receiver voltage drops to a specified level, thereby allowing you time to get your boat ashore, while you still have control of it, and before it catches fire, due to your lipo dropping below its minimum voltage. But you will need to purchase the cheap Hitec HPP-22 programmer to set your voltage to your own chosen level. Voltage telemetry is included with every Optima receiver. You will not need to purchase the HPP-22 programmer if you run 4 or 5 cell NiMH battery packs to power your receiver.

If you run Spektrum DX6i or DX7 systems, you will need to purchase expensive additional telemetry equipment to get these same features, and even then, warnings will only be sent to iPhone of iPad devices.