Just been reading up on these on the forum and in reviews. Will be looking to connect via the OBD2 port to save running cables all over the place. Interested in the Halfords and AA models. Halfords mono crystalline are supposedly more efficient, cheaper with current discounts and vouchers but have what looks like simple metal frames and size unknown. AA TFT models less efficient, huge but car friendly frames.

Anyone used any of these, or know the physical size of the halfords models? Will be in the windscreen facing almost due SSE to hopefully keep battery topped up a bit with my short infrequent journeys. Chris

2014 FFRR 4.4 SDV8 Autobiography Barolo Black
2012 RRS SDV6 HSE Baltic Blue
and before I saw the light:
2011 Suzuki Grand Vitara SZ5
1998 Ford Mondeo V6 Ghia X
1990 Citroen BX GTi
1973 Triumph GT6

I was also looking into these for my ongoing battery drain you know about!
I’m undecided currently- reviews are mixed, some saying that they can actually drain the battery even with these so called smart controls that internally disconnect as such when there’s not enough light to benefit any charge.
I guess will have to take a gamble and see if they’re good or not!

I bought an AA 4.8W model for about £40 https://www.ebay.co.uk/itm/233532721602. I checked it on my old battery in full sun at the beginning of the month and it was delivering around 300mA and it did charge the battery, slightly.

I completely blocked it off from the sun and current reduced to zero but didn't go negative so the blocking diode was working OK.

I haven't tried it in the car yet so don't really know what to expect when it's behind a windscreen.

It is pretty big though but fortunately we have a lot of real estate behind the windscreen!

The, erm, "test bench":

Click image to enlarge

In all honesty theyre a complete waste of money. You have seen it charging at 300mA in bright sun and clearly facing the sun. Once you move it behind glass which reduces the output by up to 50%, not be facing south, not at the best angles the output will plummet. The self discharge of a AGM battery is around 0.63 A/h per day. You need to be charging 24/7 at 27mA just to cover this loss, your panel will only be outputting it's peak rate for around 4 hours per day and very few days of the year. The current feeding the systems in the Range Rover will rapidly take above the output of this PV panel, it will do little to help your battery discharge. BMW i3 Electric Car
2012 Full Fat RR 4.4 TDV8 (now gone)
2006 VW Touareg 3.0 TDi V6

I use these on my seldom used cars and do a good job:-
https://www.amazon.co.uk/gp/product/B088GX...8&th=1 Range Rover 4.2 SC
2 Range Rover Classics - one from new but both rusty now.
Rover 3.5 Coupe had since new.
Subaru Legacy 3.0.
BMW K1200RS.