Does new battery swap company "Ample" finally get it right?


A new company offering battery swap for EVs launches today. They convert the car's battery pack to use standardize 2.5kwh modules, and cheap robotic stations swap them out. Battery swap has a number of useful advantages, but it's failed before because it's not actually that great a solution for private car owners, and it standardizes the most important area of EV innovation.

It's not a great solution because it's gasoline thinking. EV owners who have garages charge at home and almost never charge elsewhere, so swap gets them nothing except on long road trips. But Ample is correctly aimed at fleets -- Uber drivers, delivery vans -- for whom gasoline thinking can make sense. It's quite expensive, though.

Read my detailed analysis of all the factors in a new Forbes site article at: “Ample” Launches New Battery Swap For EVs That Could Avoid The Failures Of Previous Ventures


Thanks for the comprehensive comparison of the pros/cons of battery swapping.
For fleets of small vehicles, the high energy price Ample charge would have to be offset by saving time on recharge or perhaps by allowing the purchase of a cheaper car with lower range to be feasible. EV range is good now, but batteries are still expensive. If battery price continues to track lower though this scenario might close quite soon.
There is the possibility that Amazon or others of similar size decide it is worth rolling their own battery swap network if they think they can do solar a better price.
Long range large trucks does look like a sweet spot to me, as they might be the only practical way to do long haul electric as it seems like joules/kg is improving less quickly than some other metrics.
Lastly private electric aircraft (like the blackfly IIRC) might also seem like a sweet spot. Range is low because of weight limitations, so any reasonable flight would require multiple stops. Waiting for 45 minutes at each stop would be tiresome. The problem with this use case is of course there are very few private electric aircraft at this point.

One thing not clear is whether the vehicle buyer has to buy their initial set of modules, or they buy the car without paying for the initial modules and then swap them as a service. The latter is very attractive (but would have to demand you swap as you could get one set of modules and charge mostly at home/base.)

Yes, short range planes could consider this. A bit harder to standardize. This would be for rare use. Truth is, if you have a plane with a range less than 100 miles, you would not want to take a lot of trips where you land every 80 miles (or less) even for a quick swap. Landing and takeoff each take a fair bit of time (though perhaps not evtol) and takeoff takes energy.

Great analysis, as always, Brad. Having a fast-swap capability would also be good for those people who live in Multi-Dwelling Units and don't have access to chargers. It might also be helpful to those of us who have a 90-mile range electric car and want to go to San Francisco without range anxiety.

The Ample system is similar in concept what Atmo Auto Power system demonstrated at CES2017. They were demonstrating 30-second battery swaps using a low-profile autonomous robot in what looks to be roughly a single parking spot. Atmo Auto Power's president pointed out in my interview with him, as you did, that the swapping approach would allow slower charging. He also talked about the idea that swapping would be ideal for autonomous fleets.

Recently over on Jalopnik there was a discussion of Ford's newly announced electric Transit van with a range of ~100 miles. Many people derided this as not enough, but several actual fleet operators chimed in saying 100 miles is more than enough for daily use. So I'm wondering what kind of fleets besides long-haul trucks could benefit from this? If your fleet can't cover the total number of miles needed per day, one option is to just buy more vehicles. What's the crossover point where the capital cost of more vehicles exceeds the cost (and limitation of vehicle selection) of battery swap? And for the long-haul trucks, you'd have to build a lot of battery swap stations all across the country. How do you do that incrementally? I suppose you could try capturing one route at a time. Would be a totally different market and approach than local fleets.

Yes, I think an urban van might well not do more than that. If you are doing suburbs with highway you could need more. A robotaxi doing that would do more - every run to the airport can be a 30 mile round trip in a lot of towns.

I think that Ample is expecting people won't bother with night charging if they have Ample. That they will treat it like gasoline, come in when you are low. I am not sure that's true, not at 40 cents/kwh.

For long haul though, it can make sense. You might swap every 2 hours (140 miles) perhaps. You need a break anyway. Ample claims their stations are cheap and easy to install so loading a highway with stations every 50 miles is quite possible for them. As you say, you only need to do the route the trucks are driving. But they are not doing long haul at first, only smaller commercial trucks

Maybe the most poorly written article I have ever read.

For fleets just swap vehicles. Even for road trips this can be an option once rental EVs are more ubiquitous.

Battery swap can make sense if vehicle downtime is expensive. To swap vehicles you need more vehicles, not just more batteries. That is often OK, but if high duty cycle on the vehicles is important to your economics, then battery swap could be a better answer. In addition, typically with vehicle swap you want to charge that vehicle right now, losing the big advantage of battery swap where you charge the batteries when power is cheap only, and at a rate that causes less damage to the battery. Being out of service for a vehicle is more expensive than for a battery module.

I guess there's a niche where battery swap can make sense, but it's hard to see where it is, because battery swap is so expensive, because batteries are such a large part of the cost of a vehicle, and because such a large portion of the overall cost of a fleet vehicle is per-mile.

Battery swap will become cheaper over time, but so will the cost of equipping your vehicles with longer range batteries.

That's what these guys claim to have done, made it cheaper. Though at their price, I don't think it's enough cheaper. Though it's cheaper than a DC fast charge during the day. But the ideal plan for a fleet would be to charge up at night, and if that's not enough, do a swap of just enough modules to last the day at some convenient time in the day. Though one could argue you should size your vehicle with enough for 55% of a day's driving, and do one full swap mid-day if that fits the schedule. That could be cost effective. You carry a lot less weight of battery which has many benefits, including initial capital cost.

Swap also works on long-haul when you want to drive for 11 hours straight and can't be productive during even a 40 minute fast charge.

By cheaper I mean cheaper than what these guys are doing.

What rate are you thinking of for "DC fast charge during the day"? Consumer prices?

If prices during the day for your business are so much more expensive than prices at night that you can afford to buy extra batteries, you can always charge batteries up at night and use them to charge other batteries in cars during the day. Yeah, it's not perfectly efficient, but if the price differential is enough, it could be worth it (especially if you have cheap batteries around, like used ones from previous generation fleet vehicles).

The price differential probably isn't enough, as if this were viable at scale the electric companies would just do it themselves. Are large commercial TOU electricity price differentials really so dramatic to make it worth it? I'm not sure where to find prices online, and there are a lot of factors (large commercial operations generally pay on many variables, usually including peak demand, so putting all your demand at night is probably not usually a good plan).

And why are you running EV cars anyway? If it's genuine environmental concerns, charging at night, when energy generation is usually the dirtiest, probably isn't the best move. EV is adequate (though still expensive) for most consumer uses, but if your usage is so high that you can't fit a battery with enough range to handle it, maybe you shouldn't be using EV cars in the first place.

There is an in-out cost for batteries, both in electrical losses and in battery degradation, but yes, it's less than the cost of power in the day. Though that argument applies to any power you buy in the day, including for air conditioning. The AC load had in fact made popular a new generation of air conditioners that make ice at night and use it to cool in the afternoon. Over time, most air conditioners might shift to this until solar makes daytime power cheap.

Of course some fleet vehicles work at night, like a fraction of the taxi fleet, so they can't sit connected all night.

Around here, late afternoon power can be 51 cents/kwh at my house. You may get it cheaper wholesale or contracting with your own supplier if you have a known demand to buy the contracts. Guys like Tesla sell it for just 28-31 cents/kwh by subsidizing the afternoon with the other parts of the day. Anybody not selling at the spot price will be subsidizing. This is a fairly high extreme.

Over time, though you want solar power which does not come at night, and only so much wind comes at night. Note people are also doing EVs not simply to be green. Green is a side benefit to many.

In that solar time, the best time to charge is 7am to 2pm, but that's a busy time for fleets. Thus the swap.

I assume you don't have a large commercial contract with your electric company like an operator of a fleet of electric cars would, so what you pay isn't helpful. Take a look at and show me what commercial rate schedules are anything close to what you're paying.

I highly doubt Tesla is paying more than $0.30 per kilowatt-hour more than a tiny fraction of the day in a very small number of markets. That is their average cost because their costs include much more than just a per kilowatt-hour price.

In any case, it shouldn't be a problem for most fleets to mostly avoid charging during the late afternoon, if they really needed to. 6 hours at 30 miles an hour is only 180 miles, which is much more than the range on even a base model Tesla Model 3.

Who's running a fleet of EVs for a reason other than a desire to be green (or a government mandate to be green)? The other benefits do not outweigh the costs. Not for a fleet that needs a lot of range.

I suppose a mail delivery company might be at full capacity the entire time from 7am to 2pm on a regular basis. And I suppose if that delivery company wanted to run on solar power, battery swap might be a way to do that.

Maybe that's one niche where battery swap might make sense. I did say at the start that there are probably niches where it does. Just not many.

(Vehicle swap could probably also work for that niche about as easily as battery swap, with about a 20% increase in vehicles, charge for an hour, drive for five. You could load up the vehicle while charging it, so maybe it wouldn't even require much of an increase in vehicles.)

Tesla buys enough power that they probably contract directly with generation providers rather than using the local utility. Around here though, the bigger cost is the cost of transmission (for all customers.) Tesla charging stations need very high level service (megawatts of peak load, and worse, they will spend long periods near that peak when the stations are full.) The stations are expensive to install though they typically get free land. Tesla claims the 30 cents/kwh price is a break-even price. One reason Tesla has put solar at many of its stations is you don't have to pay delivery prices for that power.

Why run an EV fleet? Lower operating and maintenance costs. You drive 100-200 miles/day and the total cost of ownership of the EV is way less. Particularly charging at night rates. And yes, you can do your mid-day recharge from 2-3pm, though it's a problem if everybody wants to do their charge then. It's a problem if everybody wants to swap then, too, but swap time doesn't affect the cost.

Tesla claims the 30 cents/kwh price is a break-even price.

Yes, but they don't explain how they are arrive at that figure or what costs they are including. It's most likely an average cost though, not a marginal cost, as it's very high.

Why run an EV fleet? Lower operating and maintenance costs.

Not if you have to recharge (or swap) at time when you'd like to be on the road.

Sure, I presume Tesla books great rates on electricity as a major purchaser but those supercharging stations are quite expensive to build and maintain. And Tesla actually maintains them and is building lots more.

I expect most EV fleets that do urban driving don't need to recharge in the day. But if they do swap is a reasonable thing if it's 5 minutes. 30 minute DC charge isn't that bad either because almost all drivers take a break in the day. The savings can be a lot.

I expect most EV fleets that do urban driving don't need to recharge in the day.

So much for battery swap being useful, then.

But if they do swap is a reasonable thing if it's 5 minutes.

5 minutes plus the time to travel to/from the swap facility. And that's if you don't have to wait in line when you get there.

And it'll no doubt be really expensive.

Maybe EV will be cost effective for fleets that need a lot of range one day. It's not there yet.

(Once we have robocars, the time to charge won't be that important, except for long trips, and EVs will make a lot of sense outside of those long trips. Even for long trips, it might be feasible to do vehicle swap, at least for the humans on the trip along with small carry-ons. Or maybe we'll just burn a little bit of gasoline on long trips. The idea that we have to go 100% EV or bust is flawed. Switching to EV for all trips under 200 miles could be tremendous for the environment, if we can generate the electricity cleanly.)

I agree. Swap could be useful for those cars that do want to do more than their range in a day, which is true of Ubers that do runs outside the city, which is Ample's first market. Ample also hopes that fleet customers will just go with swap and not bother putting in night charging for the fleet. If your fleet does not return to a depot that could make sense, or if you don't want to install even Level 2 for every car in the depot. In addition, many Uber drivers can't install charging at home. For them it's fast charging or swap, and swap can compete with fast charging on cost, and it's better on the batteries and faster. It's pure gasoline style operation, though with fewer stations.

SACRAMENTO, Pa., May 26, 2021 /PRNewswire/ -- EVSR (Electric Vehicle Sports Racer), a program of Entropy Racing, is thrilled to announce another first in EV Auto Racing History. The Team at EVSR is preparing for the USAF 25 Hours at Thunderhill endurance race in December 2021. EVSR will be the first EV Race Team to endurance race an all-electric race car with hot swap battery packs allowing continuous racing with no down-time for charging.

EVSR has developed a system of hot-swap battery changing and is able to swap battery packs and do pit stops in just a couple of minutes. The team will be practicing and refining the hardware and procedures to do a full battery swap in less than 2 minutes per swap. While EVSR has participated in 4 previous endurance races (and won its class against 2 other gas cars), this will be the first time any EV team in the world will go head to head with a full field of gas cars in an endurance race using one car for the entire race.

Since the design and build of their Generation 1 EVSRs in 2013-14, Entropy Racing has been refining battery containment to improve overall safety, emergency management, and range. The Generation 1 cars were equipped with a sealed aluminium box that weighed 100 lb (45 kg) per pair and were fixed to the frame. With the dawn of the Generation 2 EVSRs, Entropy Racing designed and tested 3 different containment prototypes to address various issues with the Gen 1 boxes; as well as having the ability to exchange discharged battery packs for charged packs in very short order. The Gen 2 boxes are 30 lbs (14 kg) lighter per pair, contributing to the Gen 2 EVSR being almost 150 lbs (68 kg) lighter than the original, weighing in at around 1850 lb (840 kg).

EVSR race cars are excellent training tools for the novice driver and are also driven by, and have earned the respect of. the most seasoned racing professionals. Professionals that driven our race cars include 5-time Daytona 24 Hour race winner and professional sports car champion Andy Lally, 5 time US and North American Rally Champion Tim O'Neil, 1984 24-Hours of Le Mans Winner Rick Knoop, and talk show host and car aficionado Jay Leno.

I have contended on behalf of this since 1995 when I heard the late Alisair Cooke write about zero emission vehicles required in California for 2000, they seemed not to arrive. Swap is the only sensible way. When petrol cars came along no-one would have invented a pump to spend half an hour to dribble in a few gallons to give a range of anout 100 miles, but that is what current EV drivers are expected to accept. We all accept standard dry batteries, AA, AAA, etc. No-one has made a BB. EV batteries should be no different. SEAT have built the Minimo with a 15Kwh exchangeable battery, but even some of their dealers don't know it exists. This would be preferable to a squad of 2.5Kwh minis, and all cars would have, 1, 2, or 3 of them to enable partial swap, and no need to get completely flat. Tesla's idea to make it part of the structure means the car will only last as long as the battery, a good dea at Tesla prices? The gas industry has ALWAYS had swap, no-one owns a cylinder, and it works. No mention of the 28 different re-charge systems in UK, that means 27 too many. So expect fossil fuels to outlast current switch-off desires.

So there are a few things to this that mean it's the best option for electric vehicles going forward. If people start to move away from thinking about the battery as something they own, to a source of energy they lease/use.
1- Battery standardisation
If the governments came up with a standardised format of modular compact batteries that can be 'plugged' into a vehicle or in bigger vehicles, multiple batteries. I would suggest one standard form could be 20kg which could be manually handled like a suitcase. Present technology one 20kg battery would get you very far but over time this will change and improve as the energy density of batteries improves.
2-Battery Station (petrol station)
So big energy companies would be the owners of the batteries and the charging would be handled centrally at the station. Why is this better? Most Li-pol or Li-ion batteries should not be charged at greater speed than 1S meaning a 10amp battery should be charged over 1hr at 10amps Individual owners charging 10 batteries separately takes 10hrs time. However, there is a charging trick most drone or rc enthusiasts know about. If you charge the 10 batteries in parallel with a 100amp charger you can charge the same 10 batteries in 1 hour! The charging station could accumulated spent batteries during the day and give out charged batteries they have done in bulk over night off peak on a large parallel charging rigs
3-Lower cost of vehicle and less charging infrastructure at home.
If the big energy companies design develop and maintain their standard form batteries you cost of the vehicle will plummet. Standard 13amp uk home charging would be a backup home charging option. A home bug charger wouldn't be needed.
4 Safer, less weight, efficient vehicles
Its well known many electric cars are travelling around with a very large chemical incendiary bomb under the chassis. Smaller changeable batteries might not get you as far as a 1000kg battery but it will require less energy to lug around the country and be safer for stopping
5 - latest tech
Currently, The second you buy your electric car its battery is out of date and ageing. If the battery stock is developed and maintained by the energy firms. When you lease, you will know you have a charged battery of the latest technology. 20kg today will get you know here but 20kg in 10yrs....who knows. Competition will drive the development as each firm will want you to use their battery.
6 sustainability
If batteries are a standard plug in format the case can be recycled when the battery becomes obsolete.


Battery innovation is going crazy, not just in cells, but pack form, cooling, charging systems etc. Not the time to standardize!

Petrol stations are gasoline thinking. We don't need it.

Yes, you don't need charging at home, but charging at home is great. It's much cheaper, the wires are already there for low-power charging (which is all you need 99% of nights) and often for level 2. Charging at home means no travel to a swap station or waiting at one, it happens while you sleep.

I agree that being able to temporarily add more battery is a useful thing, having less battery around the city, add more on road trip. But this is a costly way to do that.

Upgrading your battery tech is valuable, but of course that comes at a cost. Somebody pays for all those retired obsolete batteries, and in the end that's you. It is worthwhile if your battery pack can be replaced when you want to do it, but that' every few years, not every day.

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