Electric Scooters - no more gas to buy?
If you do a Google search for Electric scooters or Battery powered scooters you'll probably end up with pages containing links to mobility scooters for the disabled or small "stand up" scooters with 4" wheels. If you do find something that looks like a regular motor scooter, it's likely to actually be smaller than it looks, is designed for children and has a top speed of 15mph and a range of a couple of miles (and it may well be sold by a toy store!). Finding a full sized battery powered scooter which looks like a 50/150cc gas powered scooter, is capable of a t least 30mph and has a range over 15 miles is much harder. If you do find one it's likely to be twice the price of a 50cc gas powered scooter. Why is this?
Well, one reason is that gasoline is energy dense. A little gas can produce a lot of power. On the other hand batteries aren't very energy dense. To get a battery powered scooter capable of coming close to the performance of a gas powered scooter you are probably looking for a 48v battery with a capacity of maybe 40AH. That's 4 car batteries hooked up in series. Each one will weigh about 25lbs and cost about $100. So you're starting out with a 100lb battery costing $400. You can save weight be using a Lithium-ion battery. A 48v 40A li-ion battery might only weight 30lns, but unfortunately it will cost you around $1000. Considering that a 150cc gas scooter (the whole scooter) sells for as little as $800 and a 50cc scooters can be found for under $600, you can see that a battery powered scooter is going to be significantly more expensive - and quite heavy.
Obviously you could build a battry powered scooter with good performance. You can buy an electric motorcycle with good power and range, so you could certainly make a similar scooter. Unfortunately that motorcycle is likely to cost you $10,000 or more. One of the least expensive is the ZERO FXS ZF3.3. It's $8495. Not bad, but the range is only 40 miles in the city, and half that at freeway speeds. It is capable of 75mph and it's quick (0-60 in just over 4s). But it's $8495 (but you go get some tax credits since it's electric). If you want to double the range to give you maybe 60 miles of combined city/highway riding, you're at $10,990.
So yes, you could make an excellent battery powered scooter, but it wouldn't be cheap, and cheap is the main thing that Chinese made gas powered scooters have going for them! A Chinese electric scooter would certainly be cheaper than the ZERO motorcycles, but it's still likely to be 2x to 3x the price of a similar gas powered scooter because of the battery cost. The entire engine and transmission of a gas powered scooter is cheaper than just the battery you'd need for similar electric scooter.
So are there any electric scooters? Well, there's the Liberty ES3000. It's a full size scooter with a range of up to about 60 miles (at 30 mph) and a top speed around 40mph. That's similar to a 50cc scooter. The price is $2495 with a lead-acid battery or $3395 with a Lithium battery. I'm guessing the range and speed specs are based on the Li Battery. You can get a 50cc gas powered scooter with a top speed of 35mph and a range of over 100 miles for $600. And after 90 miles you can stop at a gas station and fill it up again for maybe $3-4. You don't have to find an AC outlet and wait 5 or 6 hours.
Prodeco Phanton X2. 20mph, 25mile range, ~$1500
So as a practical, inexpensive, means of transport, electric scooters have a long way to go. If you want electric power you have to pay for it. An alternative might be an electric bicycle. Though they have limited range and speed, if your battery goes dead at least you can peddle home! You can actually get an electric bicycle for $500 from Walmart, though I suspect it's small and not very well built. There are a few decent models for $1000 and you can get something quite nice for $1500. If you want to go crazy you can spend upwards of $5000.
Jetson Electric bike (note the peddles)
The is an interesting vehicle - The Jetson electric bike. It looks like a scooter but has peddles and is legally a bicycle. The peddles are probably as much for display (and to qualify it as a "bicycle") as for actual use, because the bike weights 125 lbs and there are no gears! Top speed is under 20mph and range is "up to" 40 miles. That would probably be 40 miles on a perfectly flat road at low speed. Go "fast" or up hills and that's likely to be drastically reduced. Price is $1800.
For now though, the cheapest way to get a usable vehicle you don't need to peddle is still a small gas powered scooter, and for my money I'd say the "best buy" is probably a 150cc model.