Quantum Turbo 2x2 Xint with Charger needs battery replacement

Description

I’ve owned this Turbo 2x2 from new and it's barely been used (which is the problem). It is in beautiful condition and looks new.
Due to inactivity, the batteries are now in need of replacement.
Other than that it is fully functioning as shown by the photos:
2
nd
Photo - Unit turned off.
3
rd
Photo – Unit turned on showing 1 green LED.
4
th
Photo – Unit being charged 1 Green LED
5
th
Photo – 50% charged 2 Green LEDs
6
th
Photo – 75% Charged 3 Green LEDs
7
th
Photo – 100% Charged 4 Green LEDs
Unit charges fine but next day batteries need recharging again.
Shipping USPS Priority Mail