Got a question ,elect scooter/bike

1st, get a proper tester. Learned that from Deacon. Your tongue will twitch even with a small charge so you're far from getting an accurate reading.

IIRC, these run on SLA batteries. Usually 2 or 3 24 volt 10ah units. From your description, it sounds like you don't have a full charge. Either both or one of the batteries may have gone belly up. If that's the case, that regen wheel is not going to do much. Get that tester and check the true voltage. It should read as high as 13 volts per battery when fully charged, approx. 26 volts if it's a 24 volt pack. The tester will tell you which battery is bad. Just replace it with a new one and charge up. Take a spin and recheck your voltage. If your typical commute isn't very long, you may have to put the batteries on the charger after your ride. It's recommended that SLA batteries be charged even after a short ride. Never let them go without charging or run them down till you can't move. This will surely kill your battery deader than a doornail.......what the heck is a doornail? LOL

I've been seeing quite a few of these scooters on our local Craigs, lately. For me, they'd be good for riding on rainy days. My regular ride has a 450watt Curry unit and a 24 volt 12 ah battery pack. I can get up to at least 20mph with pedal assist. Range even with pedaling is still only around 10 miles. I'm leary of such range numbers as you mentioned, but you do have that regen wheel. Just remember that it's useless if your batteries are not up to par. Btw, I'm waiting for one to come up real cheap. That 250watt motor just doesn't do it for me. Doesn't help that I exceed the 200 lb. mark.

As a rule of thumb, you shouldn't lick anything you don't plan to eat. A cheap $8 multitester will do what you need.
I'm still in the research stage for getting an ebike, but I have built a couple of 12v systems for boats. You'll have to unplug (unscrew?) each battery individually to test them. If one is significantly lower voltage than the other(s), then the good battery will constantly be drained into the bad one.
I've found the claims from ebike makers to be all over the place in terms of speed and range. That sounds like it's at the high end.

I agree with everything that grouchyolfart has written. It's very hard to believe that your scooter/bike (really , it's a bike with fancy plastic coverings ) can achieve 45 mile range , even if the batteries are new(unless it has battery pack of 50-60 Ah and that would be very heavy bike).
Get the tester , check it out and replace the broken battery (better if whole pack is replaced). If you replacing all batteries , you should consider upgrade in battery chemistry (that will improve your range and somewhat speed - lighter vehicle). More speed you can get if you up the voltage (add another battery in series) and that will help with the range too.
You'll probably need to pedal on steep , longer hills with that setup on your bile (250 W motor is about 1/3 HP - same about average person power).
Good luck.

My most used tool is the tester. Almost everything else electrical I can do with a pocket knife and a roll of black tape.

A 45 mile range with sla batteries is going to take a heck of a lot of pedal assist as well as a very very flat terrain. I had a 250 front hub motor which was okay but I really didn't like the power of it. now I run a 600 watt friction drive I made from scooter parts.... so let me tell you a couple of things of interest.

You can change the controller for about thirty bucks to a 36 volt. Turn a 36 volt power pack and the motor watt increases to over 350 and it goes faster to... Then keep an eye on ebay and pick up a 500 watt motor that has the same mount type as yours. They can be had for around fifty bucks. So for a hundred dollars in very easy to do upgrades, you can have a scooter that will get out of it's own way.

In my state a scooter is either illegal, or would qualify as mopeds maybe. Put that same scooter setup on top of a bike and it is still a bike lol. I can run up to a 750 motor on my bike. It can do about twenty miles and hour and still be a bicycle. Hit the bike trails and everything. Plus I just like to tinker.