How to jump start a car with AA batteries


#1

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#2

Isn’t this exactly how these emergency phone chargers work? Except with a voltage boost circuit instead of using a million batteries in series?


#3

I am not a fan of his “battery holder”. Maybe he could wrap some cloth tape around it?

IMHO good, fresh nickel cadmium batteries are best for this because of their low internal resistance. I heard of a guy charging C size NiCads by holding one cell in his hand, bridging it across 12V from a car battery and pulling it off when it got warm. Thats fast charging for you.


#4

His car battery was right on the verge of having enough juice to start the car, so half an amp-hour of charge, or 1% of his car battery’s capacity, was enough to make the difference.

Don’t expect this to work for you.


#5

They’re going to “look past” his what?

I am glad he did the math on the amps. I was starting to look for it already. So 100 packs in parallel of 10 AA in series might start a smallish car on their own. But the wiring might become an insurmountable problem and it still ain’t no 350 cold cranks which would be necessary for a 6-banger in a Wisconsin winter. Nor would 10 AA’s in series perform so well in cold weather.

Interesting but not as funny as when a friend of mine popped the hood on his '72 Toyota 4-banger pickup to reveal a mishmash of garden hose, twine, wire, rubber band, pot lid, water jug and duck tape fixes that had me guffawing all over his front lawn.


#6

Let’s see, risk setting my car on fire, or just pull out my AAA card. I’ll go with curtain number two.


#7

I love that the batteries weren’t supposed to catch fire. Seems like something I’d accidentally do. :blush:


#8

Running the numbers, I’m pretty sure 100AAs in parallel x 10 in series really would deliver 350A, if the Wikipedia figure of 150 mOhm internal resistance is accurate. That’s about 5V drop; on 10 batteries in series so 15V nominal, that’s 10V left over. 10V at 350A is enough to deliver P-L-E-N-T-Y of power to the starter motor. It might not start a giant diesel on a Mack truck but I doubt the car battery he’s comparing with will either.

He is using a trick of overspec’ing the voltage to cover some of the internal resistance of the battery, which I’m going to call out because I think it’s kind of clever and he doesn’t even mention it. To get the same 10V from a 12V cell would require… 2400 batteries I reckon? So this solution is much more optimal for very high currents!

I don’t know why you’re glad he did the math if you’re just going to ignore his result :slight_smile:


#9

You should see some of his other videos. Pretty funny stuff.


#10

His “electric guitar” is a favorite of mine.


#11

But starting your car with AAA batteries is even worse! ducks and runs


#12

'72 Toyota 4-banger–back to the time when adding anything to an engine meant improvement on performance or fuel efficiency. =) ANYTHING~!

That kind of work won’t work on today’s engines, since they’re built to the price point. And oddly scheduled less maintenance work compared to cars just 10 years ago. Of course they fail more quickly…hmmm.


#13

I am very skeptical that he made his meeting.


#14

blah blah amps, batteries, blah skepticism, blah

I LOVE IT< he is FUN! yay!


#15

His YouTube channel is built around him regularly injuring himself on camera, it’s bad on purpose.


#16

Mehdi is hilarious. His videos are a great combination of humor and actual engineering.


#17

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