Less than 5 months one would expect moreNot to hard to install just watch the small screwsNot worth the money would have to buy at least 4-5 per year I got 3 years out of the one that came with it
Pros
Easy to install, fit well. Battery is working as well as original.
Cons
Some users have reported that the replacement battery does not hold a charge as well as the original Dyson battery, which could mean the vacuum cleaner loses power more quickly