The supplied mains charger produces a lot of RFI, and is considered a bit sketchy by some people.

Using a cheap TP5100 lithium battery charging module and a new common anode red / green LED (the original one is common cathode). The module can be switch to 8.4v 2S charging mode by shorting the pads marked 'set'. Construction is straightforward and should be fairly clear from the image below. I hot glued the module to the inside of the base.

The parts are available from all of the usual places. I bought the LEDs from this eBay listing and the charging module from here on AliExpress.

Thanks to users from the Quansheng UV Radio UK Users Facebook Group for their advice.

73, MM7SHX