900 mAh Battery for Game Boy Advance SP

Finally had the chance to try this new battery which unfortunately has been disappointing. The battery itself is slightly too thick so it is very snug in the battery holder and the battery cover is not flush to the case. My main problem with this battery is it’s not holding a charge and it seems to be getting worse. First full charge I was able to play about 1h, next full charge around 30 min, and the next full charge was less than 20 min. Based on the majority of comments, it looks like I may have received a defective one.

Great capacity for the SP, and best of all it fits very well.

Bought this alongside other products for my GBA SP mod, and this battery was just perfect. Lasts a lot longer than my previous battery, even with an IPS screen. I would not mind buying a second one at all if I ever get my hands on a AGS-101.

All the other batteries stating that they have a thousand MAH or more are all lies why because I bought them and then I got this one because of the good reviews I heard on it once I got it and charged it all the way I was able to play my advanced SP with my upgraded 15 level brightness screen for several hours. Don't get anything else. This is the one.

Popped right in and seems to work well after first charge and use.

Battery lasts much longer than those cheaper ebay ones. Thanks!

Just drop it in and charge. No issues with fit or bulging like one reviewer mentioned. Works as advertised. Great product to have with the IPS screen.

Great mod, especially paired with others such as an IPS screen kit. I Added some additional Kapton tape, just to hold the battery and wires snug with the housing. Very minimal bulging on the battery cover, but it's barely noticeable. Quick and easy "drop in", well worth it.
Ignore the fact that the Power LED is not on in the last picture. It's a side effect of torn trace when I installed a separate mod. :P

The back cover was bulging a bit, so I sanded the included bracket lightly with 180 grit until the SP battery cover fit flush. Otherwise, when the battery light turns red, you're still at about 50% battery life, just an observation. Love how much play I can get out of it now before needing to recharge.

02/2022 I originally bought a new battery from Amazon before I modded my SP. The battery “worked” but was no where near as good as retro mod. After switching to this battery, even with the IPS mod I get about 3xs as much time between charges. Absolutely recommend. Fit perfect into my shell, no bulge at all. Easy to install 👍

Bought this for my SP with a transparent shell and IPS screen. Definitely bumped my battery life closer to 6-8 hours at medium brightness.

That said, my battery door was definitely bulging. I made the modification to the bracket that Jeremy Secora (review on 5/15/2021) suggested and it now fits wonderfully. Basically I clipped 2 of the 3 cross-braces. I've posted before (pre-mod bracket) and after (bracket with the braces clipped).

The back door of my gameboy advance sp bulges a bit with this battery installed, however it's miles better than using my original battery that lasted 25 minutes before giving the charging light.

Not that there's much of a box involved here, but I ordered this to beef up my SP after modding the screen and it does exactly what it says it will. You have to do some careful wire management so that the battery door doesn't bulge, but other than that I'm happy!

I loved this battery pak, it fits like a glove and it lasts alot longer than the old battery pak

I read other reviews which said the battery was a snug fit in the compartment when closing the door. I had a very slight bump with my battery door with the cheap replacement shell but when I replaced the shell with a new RetroSix SP shell, the battery door closes perfectly. The bulging battery door issue may be more a case issue than a battery issue.

The battery life is great and most importantly, the lithium cell can be replaced easily. I’ll never have to worry about getting a quality battery for my SP again!

I get a good 2 hours till red light, was hoping for a bit longer but thats because i use it with in ips mod plus ez flash, the only issue is the bracket arrived with split along print layers so i had to glue the bracket back together but other than that definitely great.

Props to mahko and retro modding for bringing this mod to an accessible state for consumers

Like other reviews, my battery was slightly too thick, causing the battery cover to bulge. I use a transparent replacement shell, and a crack started to form due to the stress. Looking at the 3D printed bracket, I realized I could remove two of the three cross-braces as they were not structurally necessary and caused the battery to sit half a millimeter too high. After removing those two cross-braces, the battery cover now sits perfectly flush with a very small air gap between the top of the battery and the plastic. Without the bottom supports, the bracket is much more flexible, however when installed the walls of the battery compartment restore its rigidity. Additionally, the ability of the bracket to hold the battery in place is not compromised.

Battery performance is exceptional. With an IPS modded AGS-001, I got about 8 hours of battery life on full brightness before the console turned off. The battery indicator turns red about 1/3 of the way through its charge. When charging with the OEM charging cable it will get slightly warm, which you might notice if you put your fingertips against the battery cover.

The first picture shows the two pieces I removed in the correct relative position, the second showing the bulge before the fix, and the third showing the flush fit after the fix.

It works flawlessly and lasts forever (especially when your screen isn't IPS). The only issue I have with it is that the battery cover bulges a bit but it's nothing severe, other than that it's perfect

In my case, the slight after-screwed cover bulge is not that noticeable but as a quick solution for this I'd recommend the users to buy a "GBA SP Hard Case Cover" on Amazon or E-Bay which also provides an extra layer of protection for your device.

I leave a couple of example images below that I got from the internet regarding the cover product.