The Powerbox is different but they can do similar things. Stick to a powerbox unless you are a deep techie. The charge is easier to change, Just need to be able to get under the Twizy. without knowing what to look for they the easiest way to check the charger version is to see how long the fans run for after reaching 100% and the dash display going blank. A MK2 charge cuts the fans after a few minutes the MK1 runs the fans for between 20mins and 7 Hours.
And the how too and pictures are here DIY replacement of the Twizy charger on this forum.
But you need to be able to charge the Twizy to 100% to do this check.
The charger is under the drivers right foot floor panel. I don;t think you can see the label from there.
The MK1 charger has a breather pipe but the MK 2 doesn’t. Otherwise they look the same. Spotting the breather pipe isn’t very easy.