Can anyone help me to choose a battery charger for use on my two vehicles: a Nissan Almera 1.8, and a Toyota Hiace campervan?

The Almera is mostly used only for short journeys, and stands idle for periods of up to 2 months when I am off in the camper van. The Hiace stands idle for most of the winter.

I stupidly let the HIace batteries crun flat a few times last winter by not taking it out for a weekly run, and had to replace both its big batteries: ouch £££.

Last week, I have returned from over 2 months away in the Hiace, to find that my Almera battery was flat. I got the rescue people out to restart it, but it has flattened again.

I want to get a charger which will do three things:

1. fully charge a flat battery;
2. recondition a damaged battery;
3. trickle charge a battery while the vehicle is not in use.

So I need some sort of smart charger, and have been looking to see what's available. The Hiace has two big batteries for its engine (separate leisure battery) totally 150Ah, so I need a fairly big charger.

So far I have found three which appear to be suitable:

• Smartcharge 16, about £70
• Optimate 6, about £90
• Ctek MS7, about £100

So far as I can see, they all do much the same job. The Ctek and Optimate are both handily compact, while the heavy and bulky Smartcharge seems to have a clearer set of controls. Reviews suggest that the Optimate's controls are a bit obscure.

Any suggestions which I should go for?