RC Transmitter $5 Battery Pack

I got tired of taking out and putting in 8 AA batteries in my flysky FS-T6 transmitter every time I went out to use it. So I decided to make a single pack that is rechargeable and can be swapped in and out easily. This Mod will only work on transmitters that use (12volts) 8 AA or 8 AAA batteries.

Step 1: Gather Your Parts

3__14500 3.7v Li-ion 1200 mah Batteries

1__JST Power Connector Pair (male and female)

1__3s Balance Connector (male)

Step 2: Prepare the Batteries

Scratch the metal contact points on the batteries so the solder can bond correctly. Take your time, be very careful not to scratch the plastic. This is a very important step because solder does not stick well to shiny surfaces. There are many ways to achieve the same results, I used a dremel on low with a fine point sanding bit. In the past I've used a razor blade to scuff up a shiny smooth surface for soldering.

Step 3: Solder the Pack Together

Its important to double check each connection and give each connection a slight tug to ensure it doesn't come apart. The circuit diagram above shows how a typical 3s battery is wired, use the male JST connector on the pack. Once you are happy with all your solder connections you can wrap the battery in electrical tape. If you want the pack to have a professional look just use 2" heat shrink tubing around the pack instead of electrical tape.

Step 4: Transmitter Mod

Carefully open your transmitter and locate the power wires connected to the battery compartment. Cut the wires so they no longer connect to the battery compartment. Connect the female JST power connector in place of the battery compartment and route the wires into the battery compartment. The pack uses about half the space in the battery compartment and fits perfectly against the back cover once it is closed.

Comments

[anujpro]

If we use lipo battery of 13v for receiver. Is this OK?

[ImAtech]

Yes, but you have to use either a separate Battery Eliminator Circuit (BEC) or an Electronic Speed Controller (ESC) that has an output for the receiver.

[Khaleel123]

I don't know which transmitter you have, so check the specifications on your transmitter.

[fred3655]

Can you charge this with the regular plug the radio comes with? If not, is there a small board that could accept an AC adapter & charge the new pack? I like just plugging my radio into the wall.

[Khaleel123]

I would not recommend charging this pack with a regular transmitter charger. It's removable so you can charge it with your lipo balance charger using the 3s balance connector. I recommend charging at around .5 c or .6 amp in this case.

[ImAtech]

Transmitters that use dry cells typically do no have chargers.

[baecker03]

you can use flux on the batteries to help the solder adhere faster.

[ImAtech]

Rosin flux only. Never acid flux on electrical or electronic apparatus.

[rsmith79]

If you fancy getting a little more out of your TX, you can flash it with different firmware like ER9X (or others). It allows you to do loads more with it - including setting the battery voltage and alarm points. I run my Turnigy 9x with a 2s (7.4v) lipo that I had laying about.

[Khaleel123]

I'll have to try that eventually, Thanks.

[honey181]

Really nice instructable, though i don't own an RC plane or copter.. :(

[Khaleel123]

Thank you

[citymilko]

Any need for low voltage protection?

[Khaleel123]

My transmitter displays the battery voltage and has a low voltage alarm. Just to be safe I plan to recharge the pack when it drops to 10 volts.