MPJ 2500mAh Extended Battery for NOKIA BP-4W LUMIA 810 T MOBILE 822 VERIZON BP4W
Jul 24, 2016
There is no way this battery is a true 2500 mAh battery.
I bought this battery to replace the original battery in my two year old Lumia 822. Battery life is still decent and gets me through a typical day, but I wanted a little extra for days where I use it more heavily. I was skeptical about this replacement being a 2500 mAh unit (packed into the same exact dimensions) but for the price I figured I couldn't go wrong. Even if the 2500 mAh claim was an exaggeration (like most inexpensive off-brand chinese batteries, a label rating is good for nothing), I thought for certain it would be about as good as a fresh OEM 1800 mAh battery. In fact I was certain that it was actually an 1800 mAh battery under the label. Well it turns out I was incorrect. Not only is this nowhere near 2500 mAh, it doesn't even perform as well as my OLD battery!
I fully charged this battery overnight and used it for three weeks, thinking it just needed a few good charge cycles to break in. No dice - it consistently depleted faster than the old OEM battery. I did not change usage patterns, especially during the normal Mon-Fri work week where it spends most of the day unused in my pocket. I often found myself plugging it in towards the end of the day, even under very light use. Not the end of the world, but a step backwards. I eventually gave up and tossed the old battery back in. Lo and behold I can get through a typical day without plugging in until I go to sleep.
On the plus side it was cheap and I keep it as a spare. It also didn't get any warmer than the stock battery in any condition, charged and discharged normally (albeit discharging faster than anticipated), so it wasn't dangerous. It would certainly be better than a completely shot or damaged battery.