European Union directive 2002/24/EC exempts vehicles with the following definition from type approval: "Cycles with pedal assistance which are equipped with an auxiliary electric motor having a maximum continuous rated power of 0.25 kW, of which the output is progressively reduced and finally cut off as the vehicle reaches a speed of 25km/h (15.5mph) or if the cyclist stops pedaling." This is the de facto definition of an electrically assisted pedal cycle in the EU. As with all EU directives, individual member countries of the EU are left to implement the requirements in national legislation.
Electric bikes vary widely in price, anywhere from $999 to $2000+, so you’ll have to determine how important certain features are to the overall cost. (However, we made a list of electric bikes under $1.000 here.)The battery used to power an electric bike motor is a key factor in how expensive a particular bike is. In general, the more miles a battery can provide, the more expensive it will be, so it’s important to consider the type of riding you plan on doing. If you know you’ll be using predominantly motor-generated power, then paying a bit more for a battery with a longer range is probably a good idea. Alongside with a good quality battery, motor is the most expensive part of an electric bike. Most standard electric bike motors come with a power rating of 250W, and the industry standard in the US is 500W. Maximum power of the motor you can legally use in the US is 750W. The non-electric components used on an electric bike are almost the same with those used on the conventional bicycles. The quality of the components used will affect the maintenance costs of your electric bike down the road, and more quality components mean higher upfront cost. Lastly, there is the frame. Since the frame is basically the skeleton of your electric bike, it’s wise to select a good material that will be the optimum combination of weight and durability.
But unlike other battery mounted controllers, the Baserunner also stands on its own too. If you upgrade to a different battery model in the future that doesn't fit the cradle, simply remove the Baserunner from the base and use it as a miniature stand alone controller with your new battery pack. That's Grin thinking about your future options for you.
The Tidalforce Electric Bicycle was an electric bicycle manufactured by Wavecrest Labs from 2003 until the company went out of business in 2006. All models of Wavecrest Tidalforce electric bikes have a 36 volt electric hub motor built into the rear wheel hub and a 36 volt battery pack built into the front wheel hub. Wavecrest Labs manufactured three models of Tidalforce bikes: The Wavecrest Tidalforce M-750, the S-750 Traditional hard tail mountain bike and the iO-750 Cruiser. Any of the three bikes with an X suffix denotes that the motor is a 1000 watt motor without a set speed restriction as compared to the speed limited 750 watt version.
Ontario is one of the last provinces in Canada to move toward legalizing power-assisted bicycles (PABs) for use on roads, even though they have been federally defined and completely legal in Canada since early 2001. In November 2005 "Bill 169" received royal assent allowing the Ministry of Transportation of Ontario (MTO) to place any vehicle on road. On October 4 2006 the Minister of Transportation for Ontario Donna Cansfield announced the Pilot Project allowing PABs which meet the federal standards definition for operation on road. PAB riders must follow the rules and regulations of a regular bicycles, wear an approved bicycle helmet and be at least 16 years or older. There are still a number of legal considerations for operating any bicycle in Ontario. 
Chart: Electric bicycles are rapidly becoming popular. This chart shows the growth in sales of what the manufacturers refer to as "electric power-assisted cycles (EPACs)" in European countries over the last decade. Over 1.6 million electric bikes were sold in Europe in 2016 alone, which is about 7 percent of total European bicycle sales. What this chart doesn't reveal is that the bikes are much more popular in some countries than others: four countries accounted for 70 percent of all the sales (Germany, 36 percent; the Netherlands, 16 percent; Belgium, 10 percent; and France 8 percent). Data sourced from the report "European Bicycle Market: 2017", courtesy of CONEBI (Confederation of the European Bicycle Industry). These are the newest figures available at the time this article was last updated (September 2018).
By Max Shumpert: This article has been updated to reflect the most accurate information regarding best e-bikes available for those who are interested in new technology combined with traditional bikes. The best 5 available have changed, and information has been added to assist individuals in finding the best electric bicycles currently available on the market. The FAQ has also been updated.
Another type of electric assist motor, often referred to as the mid-drive system, is increasing in popularity. With this system, the electric motor is not built into the wheel but is usually mounted near (often under) the bottom bracket shell. In more typical configurations, a cog or wheel on the motor drives a belt or chain that engages with a pulley or sprocket fixed to one of the arms of the bicycle's crankset. Thus the propulsion is provided at the pedals rather than at the wheel, being eventually applied to the wheel via the bicycle's standard drive train.
Electric powered bicycles slower than 20 km/h without pedaling are legally recognized as a non-mechanically operated vehicle in China. According to "TECHNOLOGY WATCH", this should help promote its widespread use. Electric bicycles were banned in some areas of Beijing from August 2002 to January 2006 due to concerns over environmental, safety and city image issues. Beijing has re-allowed use of approved electric bicycles as of January 4, 2006. Some cities in China still ban electric bikes.
There is however still confusion over the various legislations involving Electric Bicycles. This stems from the fact that while places like the US and Canada offer some Federal regulation, the legality of road use is left to the various States or Provinces and then complicated further by municipal laws and restrictions. Further more there are a range of classifications and terms describing them, "Power-assisted bicycle" (Canada) or "Power assisted cycle" (United Kingdom) or ”Electric pedal assisted cycles” (European Union) or simply "electric bicycles", and as such in some cases have varying laws according to their respective classifications in some places.
The recommendation depends a lot on what you plan to use the bike for and how you plan to ride. That said, I would recommend at least a 750 (if not 1,000) watt motor, and, if you want reasonable range, 48 or 52v cells with a minimum rating of 19ah. For shorter rides, you can use a smaller battery. Multiply battery voltage by amp hour rating to get battery watt hours. Divide the watt hours by the motors power rating to get a general idea of how many hours of heavy use you might get. I’d also recommend a mid drive as opposed to a hub drive, or to find a hub drive wheel rated to take your and the bicycle's combined weight.
On the other hand, the battery doesn’t lock into the bike, which means you can’t just leave it on your bike when you park at the bike rack. Anyone could walk by and simply remove your battery. That seems like an oversight to me, though perhaps the designers assumed that such a small battery would just be easy to take with you. And it is. My wife could probably lose this battery in her purse.