Charging Electric Car Batteries with “Portable” Battery Packs

This sounds like a business venture...and in order to make any money with it, you would require stranded people in all electric cars.

Maybe a better idea, and one you could use for other things while you're waiting for people to become stranded, would be a tow behind diesel generator.

An exchangeable pack would eliminate the charging time and the transfer losses. Try that instead.

You wrote, "in case an electric car runs out of battery in a place in which there is no charging station, I would like to have some kind of portable battery pack…"

It is easier to carry AAA.

What you are describing is something like having a flashlight that has a compartment for an extra set of batteries.

When the batteries runs down you swap in the new battery and behold: there is light!

A smarter alternative is to simply buy a bigger flashlight. That way you don't have to go through the trouble of swapping batteries in the dark.

In the case of a car they already stuff as many batteries as they can without stealing all the trunk space and cargo space, so you already have a bigger flashlight.

The smart thing to do is keep your car charged and plan your trips carefully. If that is too much a pain in the butt, buy a Honda Insight.

If you are going to drive to a location and use something to charge the battery on the spot your wasting time and money. When the vehicle can be towed to a location for a charge. In the time necessary to charge the battery. The operator of vehicle set up to do a charge could tow many more.

The ability to swap them out would be better. But the manufactures have not design for that. If all the batteries conformed to some standard. That could be slide in and out. Not only could the be replace out on the road. But the many fuel stations could accommodate the also. For a fee you could pull in and swap them out and go.

The issue is who takes on the responsibility for the battery. They do go bad.

Rent a tow from a tow truck and let the regenerative energy from being dragged behind the truck charge up your battery. After a while, you could disconnect and start driving again with a fully charged battery.

most electric car manufacturers integrate the battery into their overall design and place it in such a way as to get the lowest possible CG for handling purposes. so the battery location might not even be seen by someone "popping the hood". so you really aren't going to be swapping a battery out in a roadside assistance situation. as already noted any transfer or "jumping" of the battery will include losses. I see where you're coming from but I don't think its a very viable business model. if anything I'd expect the storage of enough electrons will be just like my Harley. I ride until I begin to lose power.......I just reach down and turn the gas feed 90 degrees taking it off reserve and I know I have another 10+ miles to fill up again. I can easily see in all Selectric's having some provision to have enough energy to get another 1/4 mile+ built into the design so you can get off the hwy to a safer location to either recharge or get a tow.

Hi guys, first of all thanks for your answers!!!

I know battery swap can be a faster solution, but first of all (as Fredski has written) battery is often integrated into the car overall design. Moreover I ended in focusing on an external battery pack to be able to recharge electric cars even WITHOUT the car owner waiting for me to get there. I try to explain it better:

Let's say that I am a Smart EV owner, my battery is getting lower and I need to go to my office (which is far from any charging spot). I can go there and ask for a battery recharge… while I am at work! In this situation battery swap is not possible, but the driver can leave the energy plug window open to be recharged.

A diesel generator can work in the above case, but the difference with a portable battery pack is that I hope to have multiple packs on my VAN, leave them plugged in customer's cars for hours, then go back and retrieve them. In this way with a single VAN I can serve a lot of customers.

Market analysis is still going on but by the way a big assumption to solve is "how may portable battery packs I can store in a VAN/pick-up to make this job?".

This is the reason of my initial question

Not many.

Each pack will only be able to charge one car, and each pack will have to be almost as large as the pack that's in the car, to give it a full charge.

Not to mention...not many people will be dumb enough to head to work, knowing they won't be able to make it home. If it happens, it will only happen once.

Why not have the battery packs on little tow behind trailers made to hook up to cars without trailer hitches....That way you could have adaptable controls on the portable battery pack that would be able to charge any type of battery pack....lockable with a gps tracker...

Maybe methanol fuel cells in the little tow trailers, that wouldn't need charging, just occasional refueling....this would limit down time....they could be moved from job to job....

http://www.ensolsystems.com/products/fuel-cells/efoy-pro/

Generators capable of charging the car are not so large that you couldn't have 6 or 8 of them in your van and leave them charging the customers' cars for a while. I have a 12kw on wheels that one man can easily wheel around and in and out of a van or up ramps into a pickup.If you are seriously thinking of this venture at least you could sell the generators if it didn't pan out.

Good luck

I hope you realize that this is not a level playing field, different manufacturers use different battery voltages. You also need to understand the mentality of people who buy EVs, they're married to their cars and understand every little nuance about how to stretch their supply of electrons.

My son has a Volt, 1012 miles so far, 2.8 gallons of gas used. He knows how far he can go on battery only, every place where he can charge for free, and every place where there's a charging station for a fee. I know it's not a battery only EV, but he drives it like it is, and I suspect that most EV owners will never allow themselves to get "stuck on empty", even if a "fast charge" service such as yours were available.

Personally I think providing a 15kW generator is a lot easier than hauling multiple 400 pound battery packs around, and I can just imagine what would happen to a battery that was left on the streets of NYC unattended.

Just curious.

What is the impact on his monthly electric bill, and, is there a break on electricity for owning an electric car?

Looks like he gets 4-5 miles per kWh, and his bill has increased about 50kWh per month, but remember that he charges for free at various restaurants and parking garages.

Most of his gas consumption is when the car is unattended, the engine runs to keep the batteries warm when they fall below a preprogrammed limit, it also runs to burn off fuel as it ages in the tank to ensure that it doesn't go stale. I think GM spent over a billion dollars on the control systems alone, there's over 10 million lines of code!

"I think GM spent over a billion dollars on the control systems alone, there's over 10 million lines of code!"

I bet a good industrial PLC programer could have done the all of the exact same functions in less than 1000 lines!

If you look under the hood of a Volt you'll see some pretty impressive technology, obviously GM designed the platform for the future. For example there's four coolant loops, a large motor, a small motor/generator, battery, 100 microprocessors, two displays, a 4 cylinder engine that never runs unless you run out of battery power or as a last resort when you're climbing a very steep hill. The battery weighs 435 lbs and holds 16 kWh, but never goes below 65% usage (Hi Andy!).

Everything seems to be programmed to provide an efficient and smooth ride, just don't floor it and expect to hear the engine roar, it's more like accelerating in an electric train, the soft whine of the motors and no gear shifts, kinda cool.

They were using Windows Office Access......

I used to run a Citroen Berlingo E500 all-electric van. Best vehicle I ever owned and only sold it as I couldn't find anyone in Wales who could service or repair it. Charging it to full cost around £1 (US$1.60) and gave me about 50 miles range. With my driving pattern, which included charging for free at some places, it added about £15 (US$25) a month to the electricity bill. I could have got that down a bit by moving to an electricity tariff that gives cheaper night-time electricity but that had other complications and I never got around to it.

No break on the electricity charge for owning an electric vehicle but the UK road tax (an annual charge per vehicle) was zero and the insurance was also low.

Emergency charging vehicles of the type mentioned are unlikely to be something that would take off. At a basic level, and as has been mentioned by many contributors, generators are a much more flexible solution than portable batteries. It's also almost certainly easier for the truck with the generator to tow you to mains electricity (charging as you go!) than to sit by the side of the road charging it up.

This idea came up on the Australian Electric Vehicle Association (AEVA) forums.

http://forums.aeva.asn.au/forums/forum_posts.asp?TID=3714&PID=44469&title=new-to-the-forum-new-imiev#44469

The originator called it an "eJerryCan". The device had about 1 to 2 kW/h of battery capacity and an inverter to provide 240 VAC. The low(ish) capacity was so it wasn't so heavy that it couldn't be lifted - so it had to weigh less than 20kg.

The intention was to provide roughly 15 to 20km of travel range to a stranded EV.

Great idea. I love it.

Your analogy of "like when a laptop PC recharge a smartphone through USB cable" is perfect!

Let's see, all you'll need is a battery about the size of the car you want to re-charge.

Go for it!

I found this forum randomly and by now it is one of the most useful source of information and ideas that I have ever found about this project!!! Your interest on the topic and your answers (the positive ones as well as the negative/skeptical ones) are all very important.. so thank you so much guys

@SolarEagle @Sourdough Generators are another option that I have to investigate for sure. The fact that they are already available to be bought and they can also be sold in case the business doesn't work makes them a good way to test the process and the market appeal of a service like this. I have a couple of questions about it:

• Which additional components should I put on a generator in order to make it work on electric car recharging? It looks like that most of electric cars use the J1772 protocol do you think it can be a good reference guide to start from? (http://en.wikipedia.org/wiki/SAE_J1772#P1901_powerline_communication)
• @SolarEagle I read a bit about the EFOY generators and it says it has a nominal power of 90W. If I should think about recharging a 17kWh battery (like the most common current EV ones) is it right that I would need 17kWh/90W = 180 h in order to fully recharge it? Is there any other kind of generator that could have an higher nominal power in order to have faster performances?

@ Johny451: This is so useful for me! I will try to contact this guy. I can arrange the economic and market part of the project but I need for sure some help by someone with technical expertise on this topic. Thanks Johny451!

@lyn In order to be profitable business I need to carry as many battery packs (or generators?) as I can. About the market adoption of a service like this I believe I can make it work J Thanks for your support !

Good luck.

I would recommend you read this piece on chargers, and the comment section to get some idea what you need.....remember you may not necessarily need to do a full charge....but should certainly have the capability....

http://www.plugincars.com/quick-guide-buying-your-first-home-ev-charger-126875.html

...and this....

http://www.pluginamerica.org/drivers-seat/understanding-electric-vehicle-charging

You probably will need something like this with the fuel cell or generator.....

http://www.homedepot.com/p/Schneider-Electric-EVlink-30-Amp-Generation-2-5-Enhanced-Model-Indoor-Electric-Vehicle-Charging-Station-EV230WS/203670265#.UoOMpBqsiSo

...more....

http://www.afdc.energy.gov/fuels/electricity_infrastructure.html

Considerations for additional components to add to a generator for electric vehicle recharging: the industry has not standardized yet, although J1772 appears to be winning out in the U.S. But there are other contenders, such as CHAdeMO in Japan. Other proprietary standards may emerge. If you will service homebuilt EVs then you could run into almost any connector, but probably connectors readily available in electric supply houses. So you may need to be adaptable.

Charging voltage and current levels also vary, but most EVs will charge using 120 VAC @ 16A (slowly). Again, as the industry matures you may have to be flexible. If you service an EV that requires a DC recharge then you'll need a rectifying system that can tolerate a lot of amperes and a voltage delivery system higher than 120 V.

You will need to add a smart communications system that can converse with the EV to be charged. Many do not to allow charging unless some handshake signals occur. So it's more involved than just hooking up 120 VAC to the appropriate connector pins. If your plan is to hook up your charger and then leave to do other business, you'll also have to leave the communications system because the charging standards include periodic poll / response messages.

You may want a back-up plan in case the EV refuses to recharge because of weather conditions or equipment malfunctions. You could probably determine those cases pretty quickly, so you might resort to your tow vehicle. Note that although it may be possible to create regenerative charging while towing, you will have to tow many many miles before you'd accumulate enough charge for the EV to operate on its own. You'd also need to be able to connect to the appropriate part of the vehicle's internal electronics - these connections are not available on the charger connector.

I don't think anyone has mentioned the fact that you may not need to fully charge the car...just enough to get to the next charge station/home. Just like when you run out of gas, you don't fill the tank completely, just enough to get to the gas station.

So calculate the minimum charge you need to get the few miles more they might need.

As I said, just join AAA. They already have the service for mobil EV recharge.

If you want to do the same thing as a business, call them and ask how they do it, since they already have the equipment and process worked out.

Here is a link to what they do.

Oh, the service is free to AAA members, so if you want to compete - good luck.

That may just convince me to trade for a plugin when the service is available on a nation wide basis.

Ok what about renting the little pull behind trailers as range extender's that would allow you to take your electric vehicle on long trips, like U-haul trailers....You could have a network of pick-up / drop-off locations...This would alleviate range anxiety and the fear of being stranded....

I wonder how many additional miles you could get with a small Honda generator?

It would be indefinite, because you could now add fuel to the equation....

Somehow, I'm imagining an all electric vehicle, with a 55 gallon drum of gasoline strapped to the roof, and a big honkin' generator in the trunk....but with lots of range.

Sounds like a setup that a hillbilly engineer would come with.

Oh snap!! Look at what I just found.....somebody beat us to it.....

"

French Start-Up Develops Mobile Range-Extender for Electric Cars

EP Tender's 35 kW mobile electric car range-extender would give many electric cars nearly 400 miles of additional driving range.

Published: 11-Aug-2013

Located in Poissy Cedex, France, EP Tender is yet another European start-up looking to help solve the range issues of today's electric cars by offering a towable solution: a small generator trailer that the company says can extend the range of some electric cars up to an additional 600 km (372 miles).

The idea is to rent the 200 kg, 35 kW generators to owners of what are considered Class A and Class B electric cars, such as the Renault ZOE, whose 'real-world' battery-only range is estimated at 100 km in winter and 150 km most of the rest of the year."

http://evworld.com/news.cfm?newsid=30986

I still say a fuel cell would be cooler.......and silent.....and lower maintenance.....

How are they getting 35kw out of such a small package..??

Evidently a company called Clevertrailer is working on a fuel cell version.....

check out this trailer for small cars.....with a 360º range of motion.....

http://www.youtube.com/watch?v=56XL0TysIn0&feature=related]Video]

If you click on the picture in the post above, it shows a unique steering function on the EP Tender trailer.....too cool.....what a great idea

Evidently Lotus is working on some exciting stuff....

http://www.lotuscars.com/us/engineering/range-extender-engines

...."puts out 35 kilowatts with the naturally aspirated engine and 50 kilowatts with the supercharged unit.

The numbers might not seem too impressive, but consider the size of the engine: just 20.1 inches long, 16.9 inches wide, and 24.0 inches tall with the generator attached. That's about the size of two pieces of carry-on luggage, and it weighs between 112 and 128 pounds."...

Wow, that's impressive....

http://blog.caranddriver.com/in-depth-with-lotus%E2%80%99s-electric-vehicle-range-extender/

There's more of these range extenders than you can shake a stick at it seems.....

Even got a Wankel.....

Wow, this thing is tiny.....A gas turbine....I love it....

Found this....

"Austro Engine

Rotary engine technology is beginning to realise most of the desired improvements. Following the success of small Wankel engines in Unmanned Aerial Vehicles (UAVs) that are not electric, a manned Diamond aircraft flew in Germany with a rotary range extender from its investment Austro Engine in Austria.

Innovation in rotary engines is proceeding rapidly. In January 2013 the engine AE80R performed on the Austro Engine test bench. As a final target it will have a weight of 27 kg with an output of 80 hp (58 kw).

Compared to the AE50R (55 PS Austro Engine rotary engine) the new engine has no loss lubrication system anymore which results in an extremely low oil consumption. A dual FADEC (Full Authority Digital Engine Control) controlled fuel injection system will keep fuel consumption on the lowest possible level. The engine is designed to power small manned or unmanned aircraft.

LiquidPiston

LiquidPiston in the USA develops engines which are said to be two to three times more fuel efficient than today's engines, as well as five to ten times lighter, quieter, more powerful, and multi-fuel capable - including diesel, JP8, gasoline and natural gas. In July 2013, Connecticut, US-based advanced internal combustion engine developer LiquidPiston closed a $6.5m Series C venture funding round. The round was led by intellectual property-focused investor Northwater Capital Management and technology venture capital firm Adams Capital Management.

LiquidPiston's founder and CTO Nikolay Shkolnik said, "We are thrilled to have raised an additional $6.5m for LiquidPiston."

"Our X engine represents major breakthroughs for internal combustion engines. We have demonstrated a lightweight, compact, fuel-efficient, quiet, multi-fuel capable rotary prototype engine that is scalable from less than 1 to over 1000 HP. We look forward to working with industry partners to further develop this engine for specific market applications that value high power-density, fuel-efficiency, low-noise, and low-vibration.""

http://www.idtechex.com/research/reports/range-extenders-for-electric-vehicles-land-water-and-air-2013-2023-000357.asp

"Based in Bloomfield, CT, LiquidPiston develops advanced internal combustion engines. Benefits of LiquidPiston's rotary X engine include high fuel-efficiency (up to 2-3x more fuel efficient than today's engines), lightweight and compact (5-10x smaller/lighter than comparably powered diesel engines, with the potential to reach 2HP/Lb, 3 kW/kg specific power), quiet, low-vibration, multi-fuel capable (including diesel, JP8, gasoline, and natural gas), and scalable (1 to over 1000 HP) to serve a variety of markets. To learn more, visit www.liquidpiston.com."

Or, just by a hybrid EV with its own petrol engine.

The Volt's engine is simply a generator that provides enough power to operate the electric motors and some surplus to allow recharging while driving.

No need to reinvent the EV wheel.

That's what I though too, but it's a lot more sophisticated than that. Under certain circumstances the engine powers the motor electrically and simultaneously is coupled through a clutch/gear arrangement mechanically to the wheels.

I think that is true. I guess the Volt was a poor example to use.

Yes, if you want a really nice example, the Tesla seems to fit! Of course it already has a pretty good range.

That is one amazing car. I have driven their sports car, but not the Tesla. However, if I had the disposable income that would be one car I would love to own.

AAA is not free. There's the rub. It's $145.00 USD per year for AAA Plus®

You are getting ripped off. It's $100 per year at their website.

Their top of the line plan is $126.

How much does a single tow cost these days?

That's for a single membership.

Additional household members are extra. There's two of us.

It works out to a little over $18.00 USD per tow, for the 8 tow limit.

We have not gotten our money's worth over the years. But, the wife wants it. What's a man to do?

:)