Dude if you can make batteries that dont "wear" out ever 3 years you will be a billionaire.
All datacenters around the world have to swap their batteries out every 3 years, same with notebook and phone.
I think you are probably jumping to conclusions when you say 10 year warrenty on the battery, Dell will sell you a notebook with 5 year warrenty, but try and swap the battery under warrenty after 12 months and you will be in for a rude shock.
Wouldnt be suprised if the wall unit has the 10 year warrenty, and the batterys inside which you will be able to replace are much less.
