Wow! There are a lot of people interested in EV charging and driving costs. My article last week on putting a generator in the back of an EV to boost mileage has had more than 87,000 views already! Plus, there have been 34 comments and questions from our readers. If you didn’t see it last week, read it HERE.
I guess the skyrocketing cost of fuel is the main factor behind all these questions. I have limited experience driving and towing with electric vehicles. However, I’m working on getting a few more loaner EVs to test this summer. After all, to really understand how something works you need to test and verify the numbers.
Here are a few comments from last week:
Can generators in the wheels charge the batteries while driving?
Q: “These EV vehicles should have come with self-charging devices like others have on the braking and running of the wheels. Just think of the times all four wheels rotate and have a small alternator-type recharging system on each. Then you have no worries of running out of power.”
A: Actually, all EVs have motor/generators in the wheels, and this is what allows for regenerative braking when slowing to a stop or going down a grade. This technology does a great job of recovering perhaps 80% of the kinetic energy that otherwise would end up as heat in the brake pads or shoes. But TANSTAAFL (There Ain’t No Such Thing As A Free Lunch). So having electric motors in two wheels and generators in the other two wheels will never make extra power. This is essentially like plugging your inverter into your battery charger and expecting to create extra energy.
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What about putting a free energy generator in my EV?
And the above question is essentially about a “free energy” generator that doesn’t exist. When I was 8 years old, I designed and built a free energy generator which consisted of an electric motor connected to a generator with pulleys that would then feed the generator output back into the electric motor.
I thought it would generate enough electricity to power my house and actually tied it into the fuse panel. But, of course it didn’t, and all I did was blow a bunch of fuses. Free energy generators didn’t work 60 years ago, and they don’t work now. And any videos you watch claiming to be free energy generators are just clickbait.
Why a gas generator in back of the EV won’t work
Q: “Hi, Mike. Everything is dependent on batteries these days. I think strip out the batteries altogether and go more direct. Run the EV or whatever electric vehicle it is with just a generator. It can’t be that hard and it would be cheaper than having to keep charging it up, and hanging around waiting and see how that works out.”
A: What makes an EV so much cheaper to drive is that electric motors are much more efficient than a gasoline engine. So the 75 to 100 kWH of batteries allows you to store energy that was cheaper to produce to begin with. Gasoline and diesel fuels take a lot of processing and transportation costs by the time they arrive at the pump. And then your vehicle is still only 30% efficient at turning that stored energy into driving it.
So putting a portable generator in the back of your EV in place of the batteries is the worst of all worlds. You now have a very inefficient generator without any emission controls powering highly efficient electric motors. Once the energy is lost, it’s lost.
Can this work at all?
But this really acts like an infinitely variable transmission that can transfer exactly the needed power to each wheel on the locomotive. And it also acts like an exhaust brake by feeding the wheel generator output while going down a big grade into huge resistor panels in the roof the locomotive engine. There’s no battery storage in a locomotive simply due to scale and cost.
So are EVs cheaper to run than an internal combustion engine (ICE) vehicle?
As I’ve written before, your mileage will vary (literally) depending on the local cost of electricity. If you pay 14 cents per kWh at your house, like I do, then an EV can cost less than 1/3 of what a gasoline engine needs at the pump. But some states like California can cost in excess of 40 cents per kWh, so it may not be much of a savings compared to gas or diesel, unless you put enough solar panels on the roof of your garage to charge your EV.
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What about internal combustion engine (ICE) maintenance costs?
And don’t forget about all the additional costs for ICE vehicles of regular oil changes, transmission and differential fluid, antifreeze flush and other ICE maintenance items not in an EV. I just got a $1,129.70 quote for my wife’s Kia Sorento for its 30,000-mile recommended maintenance schedule covering those above items (not including the oil change, which was on top of that). Here are some of the things they want me to pay for at the next service interval. Yikes!
Yes, the batteries in an EV will be expensive to replace, but many of the EV manufacturers are offering 100,000 mile battery warranties. And the brakes in an electric vehicle will last a lot longer since much of that kinetic energy can be used to recharge the batteries rather than heating up your brake. And that heat from your friction brakes is lost energy.
So are EVs a clear winner yet?
Not yet, because there’s still a lot of challenges to be overcome such as enough charging stations, renewable energy production and material availability (such as lithium for the batteries). But clearly the manufacturer push is in that direction.
I firmly believe that the American engineers, scientists and entrepreneurs who invented 3-phase power, mass production of automobiles and the internet are up to the challenge. I’m watching this closely, as so many of you apparently are, and I will keep you updated.
Let’s play safe out there….
Send your questions to me at my new RVelectricity forum here.
Mike Sokol is an electrical and professional sound expert with 50+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.
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