The holy grail of electric cars is a full recharge as fast as a gasoline fill-up. We're still at least a half an hour shy of that, but startup Ample thinks it can close the gap substantially with a new take on the idea of swapping EV batteries instead of recharging them in cars. 

Electric car battery swapping isn't a new idea and was painted an unflattering shade of "unworkable" after the high profile failure of Better Place in 2013 and after Tesla retreated from early interest in the idea. Ample's twist is to put standard, swappable batteries under the belly of any car without its manufacturer having to engineer vehicles around them or share a large common battery with competitors.

"We actually don't ask (the carmaker) to make any modification to their car," says Ample co-founder John de Souza. "That's a huge one. We're not trying to sell anything to OEMs, just to sell a lot more vehicles."

Ample does this by creating its own interface tray under the car that follows the general size and placement of the monolithic original factory battery. Up into that interface Ample lifts its own standardized battery trays that add up to about the same total storage capacity. The final detail is a network of charging stations that use proprietary robotics to swap battery trays when a car drives in, whether for a full swap in 10 minutes or a partial one in less time.   

Ample's de Souza says this approach frees carmakers to do their own thing and let his company handle the business of designing and supporting swappable EV batteries within the carmaker's battery space. Ample's modular battery design also creates a granularity that makes battery repairs and upgrades much easier since an entire fixed 1,000-plus pound battery doesn't have to come out. Ample is initially focused on installing its tech into high-utilization ride-share and corporate fleets so it expects to see each car at least once a week, creating a lot of natural opportunities for easy battery service.

"For us, making a change is built into the model," says de Souza. "You don't have to do a huge recall to bring all the cars in." That has some relevance with a type of powertrain that is still in its early days of refinement and debugging. 

Another benefit to an Ample swap station is reduced "teat time": A full battery swap should take 10 minutes or less, compared to a plug-in charge which can take 30 minutes to a few hours, not including the time an inattentive driver may leave their fully charged EV lingering in a public charging space. 

De Souza says his firm has received serious interest from carmakers because Ample doesn't try to change what they do, but actually asks that they do less by not even installing a main battery in some cars. I will be interested to see how long and deep that welcome turns out to be: Batteries are the new engines and asking a carmaker to bend your way with theirs can be like asking Coke to tweak its recipe for your vending machine. Ample will need to convince manufacturers that its battery swaps are worthy of support and won't harm the carmakers' reputation at a time when all carmakers are trying to convince a largely skeptical public that EVs are as normal and reliable as combustion-engine cars.

Charging locations are typically seen as a thorny problem of both real estate and electrical infrastructure, but Ample says its technology relieves those pressures rather than exacerbating them. The company charges batteries at its swap stations using garden-variety Level II technology that's inexpensive and easy to provision, as EV technology goes. Just as AOL was able to support tens of millions of dial-up users with far fewer modem ports than that, Ample will need to keenly predict demand to allow its 10-minute turnaround with slower Level II charging. 

Much faster Level III charging, like the Tesla Supercharger network, may be the answer for many drivers, but de Souza thinks Level III charge times and time to scale are still both too long. "When we started this eight years ago, people told us we would soon have (ubiquitous) 350-kilowatt chargers," he says. "Eight years later people are still telling us that next year we'll have 350-kilowatt chargers." He also says that very fast DC charging is harder on batteries and more difficult to scale with local infrastructure. 

The "Goldilocks" solution for electric car charging is not yet clear and may never be a one-size-fits-all proposition like gas stations. But certainly for managed electric fleets that are expected to grow in prominence, battery swapping smartly addresses the real pain of charging infrastructure rather than an overstated emphasis on battery capacity.