Personally, I just think watt limits are just exceedingly poor law. Unenforceable at street level for starters. Then they never define where the watts are measured. Potential watts based on controller spec? Even those vary depending on the spin the seller puts on it. Actual watts measured leaving the battery? Watts that actually make it through the motor and reach the rubber? They never even say in the law. We all know where to get a 250w sticker.
Speed limits the only sensible thing, a low speed limit makes some sense, but even 20 mph is slower than a fit cyclist pedals? WTF with that?
20-30 mph POWERED speed limit, Idealy 25 because a typical hubmotor on 36v goes 20-25 mph.
Same limit for bike only trails. Much slower speed limit for multi use paths. 15-20 mph for ALL wheeled devices on the trail.
THE LIPO RULES. NEVER ABOVE 4.3V NEVER BELOW 2.7V DON'T PUNCTURE
Ideal charging /discharging range for Lipo, 3.65v minimum 4.1v maximum
See battery technology section, FAQ thread at the top of the page for lipo noob info.