LEWISTON — Battery-boosted bicycles, which are increasingly popular, fall into a sort of legal gray zone in Maine — and many other states — because while they are not only pedal-powered, they are not really motorized.

As a result, they can be seen as mopeds, bicycles, powered bicycles, motor vehicles and no doubt more.

Lawmakers in Augusta are trying to end the ambiguity and clarify the law surrounding the electronic bikes.

A bill before the Legislature’s Transportation Committee would essentially treat e-bikes as bicycles as long as their speeds top out at 20 mph or less. There would be stricter regulation for more powerful models.

John Grenier, owner of Rainbow Bicycles in Lewiston, said Wednesday that most of the new battery-equipped, pedal-assist bicycles are not much different from regular bikes.

He said they are used mostly by commuters and bikers whose knees and hips give them “a hard time with big hills” without the extra power boost.

Joan Churchill, a Buckfield resident and avid bicyclist, bought her e-bike from Rainbow last year and quickly fell in love with it.

She said Wednesday that in good weather, she rides it 23 miles each way to her job in Lewiston as often as four days a week. The battery, Churchill said, “flattens the hills” along the way, slicing 10 minutes off the commuting time in each direction.

What Churchill especially enjoys, though, is “that you get to ride the bike instead of grunting with the bike” trying to go uphill. “It’s just luscious riding,” she said.

Grenier, who’s owned the Lisbon Street shop for two decades, said he sold a dozen of the e-bikes last year — the first time he offered them — and thinks they will continue to get more popular. In Europe, he said, they have already grabbed a big share of the bicycle market.

Most of them don’t go more than 20 mph with the battery, he said, and stop moving when a rider stops pedaling in the same way as any other bike.

Grenier said he has not been following the proposed legislation but can see good reason to clarify the status of e-bikes so that Maine doesn’t wind up in a situation where different municipalities impose confusing rules.

For state Rep. Deane Rykerson, D-Kittery, e-bikes are just the latest evolution in transportation.

“It is our job as legislators to not only make sure these innovations are safe, but to make it easy to protect the public from this parade of transportation,” he told colleagues.

Rykerson said that establishing different classifications for various e-bike versions is a necessary step for public safety and the law.

“We don’t really want a 12-year-old on our streets with a powered bike riding at 30 mph,” the legislators said.

Rykerson’s proposal has strong support in the biking community.

“Electric-assist bicycles are devices that are being increasingly used in Maine by our members and other bicycle riders, but Maine law is silent or ambiguous as to how they should be defined and regulated,” James Tassé recently told legislators on behalf of the Bicycle and Pedestrian Coalition of Maine.

The Bicycle Products Suppliers Association in Colorado told the transportation panel that “clear rules” are needed because vague rules create “significant confusion for consumers and retailers and hinder the electronic bicycle market.”

Morgan Lommele, its lobbyist, told legislators that the 17 states that have adopted the rules proposed by Rykerson have seen e-bike sales double.

Scott Vlaun, executive director of the Center for an Ecology Based Economy in Norway, said the hilly terrain of Western Maine makes biking tough for many, especially older riders.

Vlaun said he has found e-bikes “to be a great way” to get healthy exercise while reducing his personal carbon footprint, which helps combat climate change.

He told lawmakers his organization is working on a community bike-share program that would include e-bikes. With clear regulations, he said, many more people will give them a try.

The proposed legislation establishes several classes of e-bikes, with the majority falling into one that basically regulates them like bicycles. More powerful bikes that can go up to 28 mph have more restrictive rules under the proposal, including a prohibition on using bike paths.

David Brink, owner of CycleMainia in Portland, told legislators he supports the bill because “I want to be sure that my customers are purchasing a legal device for use on Maine’s roads and paths and that there are clear rules explaining how, and where, they are supposed to be used.”

Grenier said he used to think e-bikes were sort of cheating, but he has come around.

“You still have to pedal it,” he said, and that is the key. It is not like a moped or motorcycle that runs on its engine.

E-bikes can be purchased for as little as $600, but to get a good one, people should expect to pay $2,000 or more. That ensures quality gears on the bicycle itself and a standard battery that can be swapped out, Grenier said.

He added that the technology involved is “growing by leaps and bounds” so the popularity of the e-bikes is likely to keep rising.

“We’re excited,” he said, to have a way to help people continue to ride as they age and to make long-distance riding easier.

Churchill said she liked her e-bike so much that she bought a second one so that she could switch batteries when she wants to pedal more than the 50 miles or so she can go with one battery.

Now, she said, she can “ride anywhere in this beautiful state of Maine” and sometimes get her husband out with her because the extra power is “a real equalizer” that makes it possible for nearly everyone to keep up a good pace.

Churchill said she can even tackle Goff Hill in Auburn without hesitation.

“It’s not a slog,” she said, “and that’s a real nice thing.”