Solar Powered Battery trickle charger

[julian987R]

Hi
I asked this query to no avail in the Porsche forum. Perhaps here would be a better place to ask. Due to lockdown and workload, I have not been able to drive my car for a good 3 weeks now. 

I am not very clued up on cars and wondered if anyone could help advise if which of these would be suitable to my Porsche 987 Cayman R battery (the stock one, not the light weight battery).

https://www.amazon.co.uk/Powered-Battery-Charger-C...


or

https://www.amazon.co.uk/AA-Essentials-AA1432-Batt...

or

https://www.halfords.com/motoring/battery-maintena...

or



https://www.amazon.co.uk/ALLPOWERS-Maintainer-Ciga...


They seem to vary in amps and don't want to set my car on fire! 

Any advice would be much appreciated.

Best regards

Julian

[powerstroke]

All would be fine , that’s to say unlikely to do damage, the output will only be a tiny percentage of the rated wattage unless they are directly facing midday summer sun , if you’re thinking of using the ones that plug in the cigarette lighter you would need to check it’s still powered up when the ignition is off otherwise you need one with clips to connect directly to the battery,
Hope that helps...

[mike9009]

My gut feel is a 5W solar charger, presumably used in Britain in winter will have zero impact and not worth the money.

Better to buy a decent battery and check the 'power-off' current draw is minimised.

My old VW camper was left for eight weeks last winter/ spring and started okay with no solar help.....and it takes some cranking to get it going too.

[nutsyH]

[redacted]

[JapanRed]

I used a CTEK for many years on my 911. Cant remember which model but it was excellent. So good in fact that I’ve recently bought a different CTEK for my caravan battery.