Nintendo recently released an expanded battery pack for the Wii U GamePad in Japan, which replaces the original 1500 mAh battery with a beefy 2550 mAh upgrade. Being the import aficionado that I am, I had to get my hands on one and give it a test run to see just how well it fares. Time to power up, dear readers!

The back of the package states that the GamePad will now last somewhere between five and eight hours, a significant upgrade over the originally advertised three-to-five hour lifespan. That's quite a claim! The box includes a little screwdriver so you can open up your GamePad's battery panel, and some instructions on how to remove the old battery and replace it. Naturally, the instructions are in Japanese, but thankfully the installation process is about as complicated as connecting two Lego bricks together. It's clear from the size of the battery compartment that Nintendo fully intended players to upgrade at a later stage, and only opted to include the smaller battery pack at launch to cut hardware costs.

It redefines the term "plug and play"!

I ran three tests using the new battery. The first with the GamePad idling while my Wii U was paused on the Home Menu, the second playing DuckTales Remastered with the GamePad's volume slider set to 0, and the last test with full GamePad volume.

The first two tests gave me roughly six and a half hours each before the battery light turned red, then another ten minutes each before the flashing red and eventual GamePad shut-off. Playing with the volume turned up to full gave me a little over five hours of playing, which is still considerably more time than my usual average of one and a half hours between charges. Of course, your mileage will vary given different games, touch screen usage and volume preferences. Regardless is the fact that this does exactly what it advertises, it's a cinch to install, and best of all it will work on ANY Wii U system, no matter which region your console or GamePad is from.

No worries if you have a third party charger either - I use the Energizer charging dock that tops up the GamePad and two Wii Remotes all at once, and it works just fine.

Until Nintendo decides to start selling these outside of Japan, there's sadly no choice but to import, but one of these babies can be picked up at just about any Japanese import game website for 3000 yen plus shipping (I recommend heading over to xe.com for an up to date conversion into your local currency). Anyone serious about playing Wii U games without your GamePad constantly plugged into the charger should consider getting one of these. If you own a Wii U and have the access and means to purchase items online, there's really no excuse for not updating to the new battery pack. Just in time for Wind Waker!