[Galaxy S II Accessories] cupcake2301:
I reviewed my mugen power extended battery for the sensation here - http://xdaforums.com/showthread.php?t=1371731 also before and seeing the performance i also ordered one for my Galaxy S II as this phone gives real trouble when it comes to battery life.

So here is how the review goes.

Well, as always – Mugen’s delivery was on time – took around 4 days to get to me here, it was well packed in the usual compact packing with padded protection. Though the packet was alittle whoped maybe the cargo handlers were a little rough, but that’s okay – the battery was perfectly fine.

Inside the packet we had the backdoor, the 3200 mAh battery and the warning card with all the instructions – very basic and simple.

Mugen offers 3 types of back doors with this particular battery – a black one, a white one and a black one with a stand. We got the black one with a stand.

The battery is huge, and almost double the width of the sleek and slender phone, weight wise doesn’t affect much, but obviously heavier. this battery can ruin the looks of the phone – so this is certainly not for the ones who still want to maintain the thinness of their SGS II.

Besides that the door is pretty well built, fits perfectly, not squeaky like other replacement doors.It feels as plastic-y as the stock door – though feels stronger certainly – and the the stand which has a chrome finish does give it a nice touch.

The battery is rated at 3200 mAH which is nearly double the capacity of the stock battery which is rated at 1650 mAh. Going by the capacity we should expect double the battery life, but is it actually double ? Well, we would certainly give full marks to the manufacturer – because it does work wonders.

Alright, first of all let me tell you that I have been using the phone since quiet some time and the stock battery does not last more than a day with heavy data usage which includes constant data transfer, multiple push email accounts, 24X7 connectivity to IMs, Twitter and Facebook, media playback and basic gaming and calls.

I would consider the stock battery backup pretty poor for a user like me, who needs constant Internet connectivity. Here comes the Mugen Power battery in the picture.

I used the phone with the extended battery for a few days at a go, and the results certainly were good and as expected keeping my previous experience with Mugen batteries in mind.

With same usage patterns as I had on stock battery the extended battery did last me over 2 days at a go – which is very good – a little more than double. I assume not everyone uses their phone as intensively as me, so the usage can be much more – and mind you I’m constantly connected using 3G or wi-fi which are big battery drainers.

The Mugen battery Im talking about certainly does make a difference to the way your phone looks, and it’s a huge compromise for battery life – especially on a phone as thin and good looking as the Galaxy S II, though if you are a user like me – who is on the go throughout the day – and not always near a power source to charge the phone – then it is a worthy compromise. The battery is worth it if you travel a lot and spend long hours in transit, though if you stay put at one place I wouldn’t recommend this battery for you – you can go for the thin version which has higher capacity than the stock one, though the size is the same. Overall, this battery being priced at almost $100 is certainly more expensive than others in the market – but, then it’s performance has proved it’s worth – but certainly it is not for everyone. I'd say buy it only if you need it and don’t mind the added thickness.