Flight Pack Battery

[Craigasoarus]

For years I have been using small 4.8 volt Nihm battery's like the Electrifly stuff for my small hand launch gliders. Since this very small batteries (250 milliamp) packs are no longer available can I use a 1s lipo to power my receiver and servos. My main concern is the lack of current for the servos but the size is a major problem for my use.

 

[Konrad]

Yes, but there is a lot more to the question and there should be a lot more to the answer.

All the best,
Konrad
(Wow, a 2 minute timer! Sorry I shouldn't have responded to your post)

 

[Kilrah]

A small 2S and BEC is a common solution.

 

[Wayne]

Their are voltage circuits that can bump up the 1S lipo to a little higher voltage, but it is a little wasteful. There are specialized servos these days that are designed to work with 1S lipos. A lot of people do use this for very small gliders, etc. It is an option for sure. As far a current supply goes (amps), the little lipos have a lot more current available than a NiMH or nicad pack. It is the drop in voltage you need to be careful with as many receivers do not like voltages down in the 3.5 range or below. Many servos will stop to function somewhere in the 3 volt range. Some testing with your gear would be a very good idea!

We can still order in very small NiMH cells, but think we will stop this practice as we are learning that modern servos can draw too much current for NiMH cells. This is mostly an issue when banging the sticks and letting the servo bounce back and forth. While this is a very short amp load it can cause issues.

Hope this helps.

ps. We will be offering AA sized Li-ion cells soon. Looked at AAA size, but very little mah in those, didn't make as much sense.

 

[HENNY]

A 1S battery is not a good solution. A 1S cell has a fully charged voltage of 4.2 volts and can sag to 3.7 volts depending on the battery age quite quickly. Most servos operate on 4.8volts to produce the required torque. So 3.7 volts or lower is a problem. A suitable BEC and 2S or 3S would be a safer solution.