Dear Car Talk:

Are electric cars rigged up to re-charge as they drive? It seems like there could be some sort of alternator set up on the wheels to generate power that could extend the range of the battery. Alternatively, are any set up with a reserve battery — akin to a spare gas tank like some trucks have? – John

This is a brilliant idea, John. You’ve just invented regenerative braking.

You’re about 50 years too late to make any money on it in cars, but good thinking, nonetheless.

Both hybrids and battery-electric vehicles use regenerative braking.

When the driver wants to slow the car and taps on the brake pedal, the first thing that happens is that a generator is engaged.

The wheels then turn the generator, simultaneously charging the battery, and — because it takes effort to spin the generator — slowing down the car.

If the stop is gradual enough, the car can be brought to a complete halt using the regenerative braking. In that case, the maximum amount of kinetic energy is recouped and put back into the battery.

If more stopping power is needed — the computer adds in the friction brakes (the brake pads) to stop the car safely, but then some of that energy is lost to heat.

You’ll be happy to hear that your other idea, John, the spare battery, has not been applied to cars. But you’ll be unhappy to hear that it may never be.

A spare battery simply weighs too much to lug around. It would reduce the range of the car considerably. You’d need a trailer to pull it around. Then you’d need a spare battery for the spare battery.

In fact, it’s so unworkable that, in the early days of electric cars, some manufacturers added small gasoline engines as backup chargers rather than have to add the weight of more batteries. That tells you how badly they wanted to avoid adding another battery.

So, if you can invent a spare battery that weighs about the same as a spare tire, write back immediately.

Dear Car Talk:

I have a 2003 Pontiac Bonneville that has not been driven since the March 2020 arrival of COVID-19. Long story short: It has 66,000 (accident-free) miles on the odometer and should have lots of around-town miles left.

It was well-maintained and running fine until it was parked in

a back lot three years ago but won’t start now. Upon investigation, a toad leaped out from the trunk and there was leafy green growth in the engine compartment.

It’s accessible for towing. I want to tow it to a mechanic to see what it needs to make it road worthy again. What do you recommend I ask the mechanic to check to get a comprehensive evaluation of its condition?

I’m anxious to get your reply, and thanks for your sage advice. – Chris

Well, it needs a sign that says, “Caution, wildlife area,” and maybe a pass with a mulching lawn mower. But other than that, it may not need much of anything.

Your mechanic should begin by getting it started. If he wants to be ultra-safe, he can remove the spark plugs and squirt a shot of oil in each cylinder first. Then, with the plugs still out, he can hand turn the crankshaft a few times to get the rings moving and cylinder walls lubricated.

After that, he can put a good battery in it and fire it up. If it runs, he’ll know pretty quickly from any noises, smells or fumes whether anything else is seriously amiss.

If it doesn’t run, he’ll have to do some detective work and figure out whether it’s lacking fuel, spark or both.

It’s possible that rodents chewed through some wires or dined on a crucial sensor connection. Or maybe the fuel pump relay is rusted and stuck in the open position. Given the vintage of this car -- and the fact that it was running well when you parked it -- it shouldn’t take him too long to figure out what’s keeping it from starting.

Regardless, once he gets it started, he should test drive the car, to be sure the brakes are working well and that there are no snakes under the front seat looking for those toads. Then, he should check all the key systems -brakes, steering, exhaust, cooling, etc. -- before he returns the car to you.

Then you drive it around, Chris, and see if you notice anything else misbehaving. You may not.

Got a question about cars? Write to Ray in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email by visiting the Car Talk website at www.cartalk.com.

(c) 2023 by Ray Magliozzi and Doug Berman

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