Is it legal to increase the range of an e-scooter with an additional battery?

Good morning ,

Is it legal to install an additional battery in an e-scooter to increase the range? I googled for a while but couldn't find anything. Tuning the speed or additional lighting is prohibited. However, if I only increase the range with the additional battery, I'm only changing the range and nothing else, so it should be legal. Is there a contact point I can call? The local police station or something? Just ask, just to be on the safe side?

What do you think? Do you know more about that? Because changing the range is basically like taking a power bank for your phone. I wouldn't change anything else, but my Xiaomi Electric Scooter 4 only manages 20-25km, and that's pretty weak, but I don't want a more expensive one with more power, so the option of an additional battery is very useful for increasing the range at a reasonable price.