Plug-in hybrids with removable batteries

[Wiyosaya]

The Motor Industry Research Association (MIRA), a British automotive design, development and certification consultancy, has done what many TreeHugger readers have been suggesting in the comments of many posts about plug-in hybrid cars: Removable battery packs that can be swapped for full batteries that have been charged from the grid.

Full article

Thanks to this site.

[daniel]

I am so totally not interested in having to change out the batteries to charge my car. Right now, I plug in my Xebra when I park it in my garage and unplug it when I want to go somewhere. The infrastructure cost of maintaining battery-changing stations all along the highway will be much higher than just having fast-charging batteries, which are already available!

[hill]

But daniel, I think the point is, that if you DO have to drive beyond the car's normal max range, it would be a GOOD thing, to have swapable racks along the way. Who doesn't like the convenience of swaping out their camera battery, or notebook PC battery. Same thing. Or look at CNG cars ... great you can fill at home, but also great you can fill out on the road.

[daniel]

Originally Posted by hill

But daniel, I think the point is, that if you DO have to drive beyond the car's normal max range, it would be a GOOD thing, to have swapable racks along the way. Who doesn't like the convenience of swaping out their camera battery, or notebook PC battery. Same thing. Or look at CNG cars ... great you can fill at home, but also great you can fill out on the road.

Yeah, but my camera battery does not weigh 500 pounds. And the point is that the new A123 LiFePO4 batteries can be charged in ten minutes if you have a sufficiently high-amperage charger.

Either way, at home you plug in overnight. On the road here are the proposals, theirs and the sensible one:

Theirs: Equip a hundred thousand nation-wide recharging stations with as many spare batteries as the number of customers they might see in a day, and an equal number of slow chargers, and several battery lifters to do the actual switch-out. Plus a significant amount of labor to switch the batteries, or heavy, expensive, and complex automated battery changers capable of automatically removing the battery pack, installing it into a charger, then taking another from a charger and installing it in the car.

Sensible: Install A123 batteries in the cars, and use fast-charging at the recharging stations, equipped with idiot-proof plugs (contact must be established and isolated before current can flow) for self-service charging.

It should be obvious that the investment in the first proposal is astronomical. Both require the delivery of a lot more electricity than we now have the infrastructure for, but both proposals require the same amount of delivered electric energy. So the big difference is the astronomical investment in additional batteries and the muscle men or the robots to do the switching.

Further, once we have commercially-available ultra-capacitors, the first proposal above will become obsolete and the entire investment in battery-switching robots will be worthless. Under the sensible proposal, the charging stations will require minimal if any alteration as cars switch from chemical batteries to capacitors.

[bbald123]

And swappable batteries means that those without a plug near their car could take advantage of plugin vehicle technology.

[DaveinOlyWA]

swappable batteries will never work. what happens if your brand new pack gets swapped out for a worn out pack and the pack dies? do you get another brand new pack? or do you have to track your battery purchases, go thru a lengthy warantee return process while sitting on the side of the road somewhere?

oh ya... sounds like a great plan....

i think i'd rather wait for super caps

[bbald123]

Originally Posted by DaveinOlyWA

swappable batteries will never work. what happens if your brand new pack gets swapped out for a worn out pack and the pack dies? do you get another brand new pack? or do you have to track your battery purchases, go thru a lengthy warantee return process while sitting on the side of the road somewhere?

oh ya... sounds like a great plan....

i think i'd rather wait for super caps

What? I have swappable packs on many devices. I manage to know SOC on them. Why would a car be any different?

[dipper]

Originally Posted by bbald123

What? I have swappable packs on many devices. I manage to know SOC on them. Why would a car be any different?

You mean you swap packs with strangers and unknown battery quality on your cameras, camcorders, and cellphones?

[NoMoShocks]

The real answer is to electrify the freeways. Add a couple of metal bands down each lane and then put some brushes on the bottom of the car like a slot car that can pick up the power from the lane and transfer it to the batteries. We can have an electric meter on the car and it can be added to the power use from our home meter.

[daniel]

Originally Posted by bbald123

And swappable batteries means that those without a plug near their car could take advantage of plugin vehicle technology.

Which you could do if there were fast-charging stations. But without all the extraneous infrastructure needed to swap thousand-pound battery packs.

Originally Posted by bbald123

What? I have swappable packs on many devices. I manage to know SOC on them. Why would a car be any different?

My camera uses a battery that weighs an ounce or so. I think my laptop battery probably weighs what? a couple of pounds? My 2,000 pound Xebra goes 40 miles on a 200-pound battery (lithium). Double the weight of the car and give it 100 miles of range and the battery will weigh a thousand pounds. You want to swap that out like a camera battery?

You own your camera and laptop batteries. You invest in quality to give you reliability. With swappable car batteries you won't own the battery. And you will have no control over whether they give you a good one or a bad one each time. And they'll charge you for two batteries, because while you're driving they have to have one on the charger. And due to the weight, they'll probably need a robot to swap them, so you'll pay their cost of buying and maintaining the robot. And if the robot goes on the fritz you're likely to find yourself stuck in the swap bay with a battery half in and half out.

And since batteries today (A123 LiFePO4) are capable of fast charging, all this swapping is totally unnecessary. Unless maybe you plan on using a 5,000-pound lead battery pack instead of lithium. (Patents prevent you from using NiMH due to the size restrictions. So you might as well use LiFePO4, which is better, and then you don't need to swap batteries because they can be fast-charged.)