Electrical trickle charger

Anyone recommend a good electrical trickle charger to use with classic cars that aren't getting driven every week?

You definitely need more than a standard trickle charger, otherwise you will damage your battery if left on charge for long periods. I have a Draper 12V Intelligent Battery Charger which continually monitors the amount of charge required and can be left connected for long periods. It also handles gel cell batteries. It wasn't that much more expensive than a standard charger and will probably repay itself in just a years worth of extra battery life.

Both of my classics have a battery isolation switch, otherwise one of them does have a habit of discharging its battery when you aren't looking!
Also acts as another theft deterrent, reduces the chance of fire and makes it easy to isolate the battery when you work on the car. Prevents that accidental short circuit with a spanner across the starter connections doing that 'just job' when you could not be bothered to isolate.
As Cosmo say's some of these trickle chargers are more likely to finish the battery off than keep it healthy.

I've got a Halfords trickle charger with automatic sensing. Seems very good. Was about £20. It has a green LED for "full" and red for "charging". It came with either crocodile clips or a jack plug to be connected permanently to the battery and that's what I use with my Varley Red Top battery.

I also have a battery isolator for all the reasons mentioned above. Very easy to fit and very convenient.

Am I just lucky?, I never have trouble with the Battery on the Bertie, they only time I have had to charge it is when I flattened it trying to start it with the ignition shorted out

I do have an Isolator, but it was only fitted a couple of years back and it was fine before then too.

I think yours probably gets driven more than a lot of classics Mitch! I've never had mine go flat but for £20 it gives a bit of piece of mind for a car that's parked in a chilly old garage 1,100 feet up!!