These are currently only sold to North American customers ONLY! Customs issues and not to mention shipping cost make me unable to ship it elsewhere. www.zedlabz.com is carrying these Batteries for UK Customers
Custom made battery for the Game Boy Advance SP with a true and tested capacity of 800mAh for extra hours of play time in comparison to the old and failing OEM batteries and the many clones with less than 600mAh that they claim.
The battery does not have the 2 plastic teeth that the stock battery has but this is not an issue at all with the battery as it fits snugly in the battery compartment and the pressure of the spring contacts and the cover help it stay in place just fine with the AGS-001 GBA SP. The AGS-101 SP and After Market Shells might need a shim to make better contact so I am providing a 3d printed shim with the battery but you can also print your own using the file below.