Ive just been to my local motor factors (Waterloo) & they have a solar panel with a built in battery charger which either plugs into the OBD or it also has connectors to go straight to battery.It does look a good bit of kit & it is AA branded so should be ok & at under £20 I might just try one,has anyone else got one or tried one before I commit to buy.This is the one but it’s cheaper from Waterloo.
https://shop.theaa.com/store/home/car-battery-solar-charger

Andy. Andy.
21 Ford Ranger
Gone but not forgotten
Focus RS Red Edition
2015 RRS AB Fuji.
2014 RRS SC Santorini
2016 VW Amarok
2014 RRS AB Fuji
2012 RRS Red Edition Fuji
2015 Nissan Navara
2012 RRS SE Santorini
2008 RRS White
2007 RRS Santorino

I've found them good on other cars.

The RRS is a real battery drain though, so you would be better off with a CTEK charger if you have a mains socket near the car.

If you get a solar, you may need to connect under the bonnet for best results.

Mine is parked up all week with sun on front windscreen most of the day,,it’s just to keep it charged once I hard wire my dash Cam.im sure this will do it especially being able to connect straight to obd.

Andy. Andy.
21 Ford Ranger
Gone but not forgotten
Focus RS Red Edition
2015 RRS AB Fuji.
2014 RRS SC Santorini
2016 VW Amarok
2014 RRS AB Fuji
2012 RRS Red Edition Fuji
2015 Nissan Navara
2012 RRS SE Santorini
2008 RRS White
2007 RRS Santorino