Most stand up e-scoots today are still powered by good old 12 volt lead acid batteries. This works since the somewhat heavy battery pack is mounted under the riding deck, which lowers the center of gravity nicely. The batteries are usually placed in series so that 2 batteries gives you a 24 volt system, 3 batteries gets you 36 volts and so on up to 48 volts. 24 volts is the most common configuration, followed by 36 volts.
Motor power ranges from 100 to well over 1000 Watts. As an adult you want at least 400 watts or so. As a kid (small kid anyway) you need less for safety reasons. Check the manufacturer's age guidance before buying for kids.
If you plan to get a high powered scoot, check out your local regulations. Passing a law enforcement professional at 30 mph will likely cause raised eyebrows and an explanation at least.
At the lower end of the scooter spectrum are some of the Chinese clones and Razor type scooters. These scooters can be had in some cases for well less than a few hundred dollars. Remember that you get what you pay for. These scooters are probably not very high quality and will likely suffer from broken plastic parts, short battery life, and so on. These scooters make great kids toys however if you find the extra cash. Again, check the manufacturer's age guidance for kids.
The clones and Razor brand scoots are actually not bad for kids. The lower end ones are mostly plastic, and frankly a little flimsy. You can see them in WalMart a lot of times. They go by the name Sweet Pea and the like.
Next in the Razor line are the e200 and e300 scooters. These are more serious kid's scooters. Here are specs for the e200 and e300:
Motor: 200 and 300 Watt motors, 24 volt power, weight about 50 pounds. Battery pack: 2-12Volt SLA batteries in series for a 24Volt system. The top speed is about 12 and 15 mph, respectively, with prices from about $175 to $300 USD. Both scoots will carry 220 pounds, with a range given as 45 minuets run time. Amazon currently markets the Razor. Reviews on these scooters vary. It seems that you may get lucky and get a well built Razor...or not.
Currie offers a range of models: 400, 500 Watt and 750 Watts, powered by 24 volt packs, and a 1000 Watt model run by a 36 volt system. Prices on Amazon at the present are: $250, $290, $365, and $470 respectively. Load ratings on these models are 220 lbs except for the 1000 Watt model which is rated to haul 260 pounds.
The Currie line is regarded as generally good, with some limitations. This is a product that would probably be better test ridden and purchased from a dealer rather than an online e-purchase.
A step up in price and power from the Currie line is the Go-Ped stable of stand up electric scooters. The Go-Peds all sport 1,000 Watt motors. The different models are defined by the battery packs installed. The Go-Ped scooter may be outfitted with up to 4 Lithium Battery packs for extended range and speed. Go-Peds are crafted with premium grade lightweight alloys.
Prices for the ESR 750 EX model start at about $750, and range upward to near $2,300 for the ESR 750 Hover-board L-Ion model. Go-Peds are considered a classic scooter, well made, and generally you get what you pay for with a Go-Ped.
There are several custom made scooters such as the Diggler. The Diggler is a large wheel scoot suited to rough ground off road riding. These scooters are relatively expensive, up to $2,500.
Last on this brief outline of stand up electric scooters are the 3-wheel models. The 3 wheelers are practical for a range of work options from delivery to Police work. Check out E-Bikeboard, Zap and Zummer.
These scooters have ranges and speeds similar to the 2 wheel models above, with increased range for some models capable of carrying larger battery packs. As for cost, a few of the Zap models can be had for less than $1,000. The rest range on up to as much as $3,000 for a top of the line E-Bikeboard.
That is a quick summary of some of the stand up e-scooters on the market today. There are many more for your consideration.
Also see our review of sit-down moped style electric scooters