After literally melting a Nokia N95 on charge overnight by using an alternative battery from eBay or Amazon, I now stick to the phone manufacturers original batteries.

SGSII standard battery

SGSII extended battery

 

I used that battery for almost 2 years, was better than the "stock"battery and no performance issues. Certainly didn't melt my phone. I'd highly recommend it!

 

Nope, I chose it cuz it doesn't need bigger back panel, no heavier, and apart from label looks exactly the same as the original battery

 

I got the pack with 2 batteries and a charger 6 months ago and it has been great.

true story - I think one of the particle detectors (CMS) at the LHC in CERN killed my original battery!!

 

I was visiting CERN with other Physics teachers from the UK in December and we were visiting a particle detectors called CMS (Compact Muon Solenoid). The LHC was running so we couldn't go down to the tunnel but we were as close as we could get when I thought I would try and measure the magnetic field strength using an app I have as we were essentially standing above a massive electromagnet. When I loaded it up it was reading 0 which is strange as the earth's magnetic field is normally between about 30 and 50 microT. I restarted my phone and when I did the battery level went down from about 60% to 5% and lost all power not long after. It was never the same again so I had to buy a new one the week after. It might have been a coincidence but I like to think that the LHC killed my battery.