Solar charger..what size?

[Usual Suspect]

Well hello again you lot.
My Berlingo is soon gonna be parked-up for 9 months. I've had the idea of (rather than let the battery drain flat, then fully charge before needing it next year)..to invest in a solar-charger to stick on my dash..
But..what rate of input do I go for..?? cratch:
My battery seems to be in good order, but do we need say a 4 watt trickle, or will a 1.8w trickle-charge be enuf..cratch:
Any of you folk use 1 of these gizmos? Verdict? Thanks in advance to all..

....cheers now U.S. alut:

[Ol'Jeffers]

I assume with the solar type charger you'll be connecting via the cigarette lighter socket.....in which case
it probably won't work as the ignition has to be on to power the socket. Even if you connect direct to the battery
you may get a problem.... Storing for that long I'd fill the tank and, observing the correct shut down procedure,
disconnect the battery and remove it to a mate's garage and put it on a smart charger for the whole period.
Better than coming back to a ruined battery. You shouldn't put any battery on trickle for that length of time.
A smart charger will keep it in good shape though. HTH