What battery trickle charger do you recommend?

We have a BMW Z4 which hasn't been used over the winter. A new battery was fitted late last year, but this morning it is as flat as a pancake. The AA has suggested either another new battery or purchasing a mains trickle charger. The car has been running for an hour to get it the batter charged up, while he was here. Do you have any recommendations?
We'd recommend a C-TEK charger. We reviewed the C-TEK MXS 5.0 here: kit.honestjohn.co.uk/reviews/review-ctek-battery-c.../
Answered by Georgia Petrie

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