[swombat]

I've just replaced the battery on my Lumia 820 after 9 months. They don't last forever. Glue is inexcusable. If they had a half decent mechanical design, foam pads would secure it in place when the device was assembled and allow replacement.

I've had a 4S for two years and have not noticed any problems with battery.

Perhaps the problem is the crap battery that goes bad after 9 months, rather than the way it's attached.

Glue is perfectly fine by me - and by most people apparently.

[harrytuttle]

Not all batteries are made equal which is the problem.

We have 25 people with Lumia 820's that are fine. I just got a bad battery.

[swombat]

Apple would have replaced that for you free of charge, or possibly replaced the whole phone. Within 1 year is still under Applecare.