l need a battery charger for my bike and feel the optimate is the best within my price range.

But l cannot decide between the Optimate 4 or the IIl sp.Both are roughly the same price give or take a £1 ...cheapest l have seen inc P&P is £42. Which would you recommed and what are the differences.....Thanks in advance.

The Optimate 4 is the replacement for the 3. It has slightly better output, so it is the one to go for unless you can pick the 3sp up at a cheap price.

l agree with JG, go for the newer one if the price is so close,

unless you can get some kind of significant saving on the optimate 3

The added advantage of the optimate 4 is the better output, so you could use it on small-ish car batteries (fiesta etc) or lend to a friend for their car etc.