SHENMZ GBA Sp Battery, Upgraded (2800mAh) Ultra High Capacity Rechargeable Lithium-ion Battery for Nintendo GBA SP Gameboy Advance SP AGS-001 with Screwdriver

It's a good battery, but the original 600mah Gameboy Advance SP states that it will last anywhere from 7 to 10 hours with the backlight turned on and about 18 hours with it off. This was tested on the Gameboy Advance SP 001 version/model, which is not the brighter version/model which is the 101 model. With that being said this 2800mah battery right out of the box gave me a good 1 hour and 36 minutes before the red light to charge came on. It then took 1 hour and 53 minutes to get to a full charge. I then tested to see how long it would run. I tested Pokemon Ruby with sound and backlight on the whole time. This 2800mah battery was able to give me a total of 10 hours and 5 minutes of play time. It's a good amount of time that it was able to produced, but it doesn't sound any better than what the original 600mah was said to produce. It's a good product but to say it's a big improvement or upgrade is a no. The installation was easy as the original and fits right in. If your old battery doesn't last more than 2-3 hours or just dead, yes you should definitely buy this replacement! Attached are the times that I screenshotted as I was testing the duration of each phase.

The battery is made of good quality was a perfect fit functions great extended gameplay, and it feels sturdy and durable

battery works well and now my GBA doesn't turn off as quickly

Great for the price my hubby said they are durable, long lasting. And they fit perfectly

A good replacement but dies quickly. I don't know if I remember wrong and this is just how it goes or if the charge is just not lasting. I'd expect more than a handful of hours of play.