Frsky QX7 expanded battery cover

When using a 900MHz module in my QX7 the 2x18650 batteries were not lasting the day. So I made this battery cover to allow fitting 4x18650. 

Please note, the ACCST QX7 can take 3S and 3x18650 will fit in the battery compartment. The ACCESS QX7 is 2S only. It cannot take 3S. But with this battery cover it can take 4x18650 connected as two pairs to give a higher capacity 2S.