Not used iSmash for macs, but certainly been happy with their mobile phone repairs and service. And there is a branch in Chiswick, at the Lightbox unit on Power Road. Might be worth giving them a go? Not sure how old the Macbook is, but I have found the batteries don't last too long these days, depending on usage. Mine started to run out of juice very quickly after about three years.
Mark Edwards ● 310d