LiFe battery in a 4x2x2 battery compartment

 Somebody on RCGroups was asking about how LiFe batteries fit into receivers with a 4x2x2 battery compartment, similar to what's on a Turnigy 9x.  Here's some pictures of how it fits (summary: just right!).  There's no stress on the battery compartment cover when snapping it on, and just enough room for the wires.  Use the power connector that looks like a servo connector.


HobbyKing 1500mAH LiFe 3S 9.9v Transmitter pack

It fits nicely in this configuration, but the 9x power connector is blocked.  This may or may not affect you depending on your receiver's connector configuration.

LiFe battery in Turnigy 9x

 Here's how the 1500 mAh LiFe fits into the Turnigy 9x transmitter.

 It uses the servo-style connector.  From the left, it goes black-red-empty.  I put a sticker in so I won't forget it.

There's plenty of room inside the battery compartment.  I put the wires on the right side.  The cover fits on very easily now!

By The Numbers: LiFe batteries

Lithium Iron Phosphate (aka LiFe, LiFePo, LiFePo4) batteries are most often used in RCLand for transmitters.  They're safer than LiPo, since they don't emit oxygen during rapid breakdown leading to combustion.  Lots of chemical detail on wikipedia.

Here's the model that fits into the Turnigy 9X transmitter.  Use the servo-style connector to plug it in.  Note that there are two ways to plug it in: only one of them works; the other doesn't do anything.

Charge Levels

 1S   3S

3.3   9.9  nominal voltage

2.8   8.4  minimal discharge

3.6  10.8  maximum voltage

Charging

You need to set your charge into LiFe mode.  Don't charge in LiPo mode. Bruce has a video here that explains how to do this on a standard 4-button charger. Here's the tldr for a typical 1500 mAh 3S:

Save Data / 01 / LiFe / 9.9 / 1500 / (hold start) / 1.0 / 9.9 / (hold start)
Save Data / pgm number / LiFe / voltage / mah / (hold start) / charge current / voltage / (hold start)