The flysky i6 transmitter is great, but it uses ancient AA batteries. I am not going to buy new batteries every few days, therefore I created this battery mod. (Or more accurately I remixed it from the battery cover by benbojangles).

I've added different sizes of the battery cover versions for everyones battery needs, but keep in mind that the flysky transmitter only takes 4 V - 6.5 V. So If you want to use Lithium batteries you'll need a voltage regulator.

If you want to make the same battery mod with the voltmeter from the pictures, you will need the printed part "flysky_battery_mod_10mm_with_voltmeter.stl" and a few additional things. (only this part is optimized for the samsung batteries)

1 - 2 samsung galaxy akkus. Two fit perfectly. This auction supplied me with a 5 pack:
http://www.ebay.com/itm/262799324825?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

A step up converter module:
https://www.banggood.com/DC-Boost-Converter-2A-Power-Supply-Module-2V-24V-To-5V-28V-Adjustable-Regulator-Board-p-1100757.html?p=C8021898693762017049

A small voltmeter:
https://www.banggood.com/0_28-Inch-2_5V-30V-Mini-Digital-Voltmeter-p-974258.html?p=C8021898693762017049

A small Lithium charger:
https://www.banggood.com/Mini-1A-Lithium-Battery-Charging-Board-Charger-Module-USB-Interface-p-89732.html?p=C8021898693762017049

and a switch
https://www.banggood.com/20Pcs-SS12D00G3-2-Position-SPDT-1P2T-3-Pin-PCB-Panel-Mini-Vertical-Slide-Switch-p-1000847.html?p=C8021898693762017049

Connecting everything is pretty straight forward but if you have any questions just ask.
Connect the Lithium battery with the step up module and the charger. Put the switch between the voltmeter so you can turn it off, and connect the step up module output, which you set to 6 V - 6,5 V, with the AA battery connections on your flysky transmitter.