Electrical wire size to jump car engine

[Hugh Byrne]

Today the car wouldn't start at a friend's house who had no jumper cables.
He had some electrical wire though.
We were just starting to jury rig something when his wife showed up with
cables in her trunk.

If we did jury rig electrical wires, we were unsure of what size would
work.

How can we determine what size electrical wire would work to jump a typical
sedan in an emergency?

[gregz]

Aside from calculations, depends how long you wait to start as it charges,
and condition of battery being driven.

Greg

[peterw...@gmail.com]

Good cables are #4 copper.

Then, there is everything else.

If the cables are actually being used to jump - that is supply 100% of the current needed to turn the starter - do not go much below #6 wire, or you will have a melted mess on your hands. If you are simply putting a charge on the existing battery so that it will carry most of the load, then pretty much anything will do as a factor of size and time. A piece of 16 gauge Zip and 20 minutes will give some sort of charge, and so forth.

Peter Wieck
Melrose Park, PA

[tabb...@gmail.com]

You can also get enough charge into a car battery with a set of AA cells, according to youtube.


NT

[peterw...@gmail.com]

On Wednesday, April 10, 2019 at 10:52:19 AM UTC-4, tabb...@gmail.com wrote:

>
> You can also get enough charge into a car battery with a set of AA cells, according to youtube.

The bible of all things possible (and impossible), and the font of all wisdom, real and imagined. Link, please?

[John-Del]

Not sure, but I think he's being sarcastic. Plenty of goof videos. I saw one where a guy cut the plug end of an AC cord, connected a standard 9V battery to the wire, and ran a 20" CRT TV with it. He said it would only last a few minutes. I wonder how many people fell for that beauty.

[peterw...@gmail.com]

On Wednesday, April 10, 2019 at 11:41:11 AM UTC-4, John-Del wrote:

> Not sure, but I think he's being sarcastic. Plenty of goof videos. I saw one where a guy cut the plug end of an AC cord, connected a standard 9V battery to the wire, and ran a 20" CRT TV with it. He said it would only last a few minutes. I wonder how many people fell for that beauty.

I believe that Tabby lacks the wherewithal to be sarcastic. But, give me 200 fresh AA batteries, wires, connectors and time, and I will make a jumper that works.

[tabb...@gmail.com]

On Wednesday, 10 April 2019 16:36:06 UTC+1, pf...@aol.com wrote:

> On Wednesday, April 10, 2019 at 10:52:19 AM UTC-4, tabby wrote:
>
> >
> > You can also get enough charge into a car battery with a set of AA cells, according to youtube.
>
>
> The bible of all things possible (and impossible), and the font of all wisdom, real and imagined. Link, please?
>
> Peter Wieck
> Melrose Park, PA

It seems credible
https://www.youtube.com/watch?v=liqIJbbDYTY


NT

[tabb...@gmail.com]

I see you're being childish again. What's new.

[peterw...@gmail.com]

Video unavailable
This video is no longer available because the YouTube account associated with this video has been terminated.

[gghe...@gmail.com]

Electroboom did that,
https://www.youtube.com/watch?v=I0utNemFsl8

GH

[Stephen Wolstenholme]

On Wed, 10 Apr 2019 07:52:16 -0700 (PDT), tabb...@gmail.com wrote:

>You can also get enough charge into a car battery with a set of AA cells, according to youtube.

That depends on the size of the "set"

--
http://www.npsnn.com

[tabb...@gmail.com]

On Thursday, 11 April 2019 11:40:23 UTC+1, Stephen Wolstenholme wrote:

> On Wed, 10 Apr 2019 07:52:16 -0700 (PDT), tabbypurr wrote:
>
> >You can also get enough charge into a car battery with a set of AA cells, according to youtube.
>
> That depends on the size of the "set"

lol

[peterw...@gmail.com]

On Thursday, April 11, 2019 at 6:40:23 AM UTC-4, Stephen Wolstenholme wrote:

>
> That depends on the size of the "set"

Let's look at that. A typical alkaline battery runs about 2.5 AH at 1.6 VDC or so. Meaning it will make about 4 watts for about an hour - a measure of the actual current it can produce.

The typical starter on a 2.0 liter gasoline automotive engine draws about 200 A at start. More if the engine is cold, more if a diesel, more if worn and so forth, but for the purposes of this discussion, figure 200 A at 13.6 VDC. That comes to 2,720 watts for about three seconds - average crank time for a well-tuned, cold engine. Now, work the math and figure the number of AA batteries required to put that much charge into a battery for the requisite period.

Now, figure that the battery failed for a reason. What does a sulphated cell look like? It can be done. But the cost, trouble and time require, as well as the likelihood of the source materials should be lying around....

Keep that solar panel trickle charger. It will be a much better bet.

[et...@whidbey.com]

Speaking of solar chargers, I have one charging the 6 volt battery in
my Ford 9N tractor. The panel is rated at 7 watts max. Here in the
great Pacific Northwest, with the cloudy days and all, The thing is
charging at about 17 milliamps. Open circuit voltage is 18 volts. But
when the thing is connected the battery voltage measures at 6.5 volts.
So I don't think there is any danger of overcharging unless the sun
goes nova and really lights the panel up. But I was wondering how to
calculate the wattage. is at 18 volts times 17 mA or 6.5 volts at 17
mA? I think I should use the open circuit voltage but I don't know.
Eric

[Ralph Mowery]

In article <odpuaetlmvevs3s6p...@4ax.com>,
et...@whidbey.com says...

> Speaking of solar chargers, I have one charging the 6 volt battery in
> my Ford 9N tractor. The panel is rated at 7 watts max. Here in the
> great Pacific Northwest, with the cloudy days and all, The thing is
> charging at about 17 milliamps. Open circuit voltage is 18 volts. But
> when the thing is connected the battery voltage measures at 6.5 volts.
> So I don't think there is any danger of overcharging unless the sun
> goes nova and really lights the panel up. But I was wondering how to
> calculate the wattage. is at 18 volts times 17 mA or 6.5 volts at 17
> mA? I think I should use the open circuit voltage but I don't know.
> Eric
>
>

YOu really need to load the panel with a resitive load. If it really is
putting out 7 watts,that resistor should be around 5 to 10 ohms. Then
measure the voltage and current.

You are just barley putting into the battery (when mostly charged) any
power at all. It would be the 17 ma times what ever the open circuit of
the battery is ( say 6.3 maybe) minus the charging voltage (6,5 in your
case) or about .2 volts. So .2 x .017 equals almost nothing.

If the battery was mostly dead you would have a much different ammount
of current if that solar cell is relly 7 watts. The cell is in very
bright sun is it not ?

I have a lawn tractor with a 12 volt battery and a panel hooked to it.
It has ran 2 winters hooked up for about 5 months at a time and no
problem so far and the tractor starts right up with a good spin the
first time of the mowing season. Water does not boil out over the
winter.

[tabb...@gmail.com]

It's delivering 6.5v at 17mA. 6.5 x 17m = 110mW, 0.11 watts.
At 18v it would deliver less current thus less power.


NT

[tabb...@gmail.com]

On Thursday, 11 April 2019 12:32:32 UTC+1, pf...@aol.com wrote:

> Let's look at that. A typical alkaline battery runs about 2.5 AH at 1.6 VDC or so. Meaning it will make about 4 watts for about an hour - a measure of the actual current it can produce.
>
> The typical starter on a 2.0 liter gasoline automotive engine draws about 200 A at start. More if the engine is cold, more if a diesel, more if worn and so forth, but for the purposes of this discussion, figure 200 A at 13.6 VDC. That comes to 2,720 watts for about three seconds - average crank time for a well-tuned, cold engine. Now, work the math and figure the number of AA batteries required to put that much charge into a battery for the requisite period.
>
> Now, figure that the battery failed for a reason. What does a sulphated cell look like? It can be done. But the cost, trouble and time require, as well as the likelihood of the source materials should be lying around....
>
> Keep that solar panel trickle charger. It will be a much better bet.
>
> Peter Wieck
> Melrose Park, PA

Let's see if we can improve on that.

Most cars don't need anywhere near 3s of cranking. Crank current varies quite a lot, and most vehicles can still start at below normal crank current/voltage. And of course the lead acid battery does already have at least a bit of charge in it fwiw.

A string of AA cells delivering 4Wh each,
for 10 cells that's 40Wh, or for 12 cells 48Wh. At 12v that's 3.3-4Ah.
At 200A cranking that's 3.3-4/200 = 1 - 1.2 minute cranking.
At 100A cranking it's 2-2.4 minutes. Far more than enough.
10 minutes of charge time from AAs should be plenty.


NT

[Trevor Wilson]

**It depends on a vast range of factors, including:

* The length of the wires (and this is the most critical one).
* The ability of the flat battery to accept charge.
* The size of the engine to be started.
* Whether the engine is petrol (gasoline) or Diesel (Diesels are much
harder to start).

You could, for instance, arrange a nice, slow trickle charge into the
flat battery over an hour or so, using modestly sized wire and still
start the engine.

I keep one of these in my car:

https://www.baintech.com.au/btcap

Mine came from Aldi and cost AUD$129.00. It can be charged from a
variety of sources, including the host battery, USB wall wart and a
laptop USB port.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

[Michael Terrell]

This was almost 50 years ago, but I jump started a 225 slant six in a 1970 Plymouth Gold Duster by parking my car with the chrome bumpers touching, and some aluminum clothes wire. Luckily, I was wearing heavy gloves, because it started to droop from overheating, but it did let a coworker start his car after work. My car was a 1963 Pontiac Catalina, with the largest battery that would fit into the holder. It was below zero outside, so we didn't want to stand there in a high wind, waiting to charge it from my car.

[peterw...@gmail.com]

Operative terms from the OP:

"Jump"
"Typical Sedan"

Nothing about taking an hour or more to cobble some sort of device from some sort of material, that may or may not put sufficient a charge on a flat and/or dead battery (two different things) for eventual conventional starting.

So: #4 copper cable. Less/not copper is a risk. Hot metal spatter or an explode lead-acid battery, or even a series of exploded AA batteries is no fun whatsoever.

Guys and gals: Give advice as if it were to a human being that you might possibly care about. And think about that advice as you give it. What you do for yourself and with only yourself at risk is fine. When you suggest that to another, own it and 100% of the potential consequences - even the possible limitations of the recipient.

[Fox's Mercantile]

On 4/12/19 9:48 AM, pf...@aol.com wrote:
> Guys and gals: Give advice as if it were to a human being that you might possibly care about. And think about that advice as you give it. What you do for yourself and with only yourself at risk is fine. When you suggest that to another, own it and 100% of the potential consequences - even the possible limitations of the recipient.

And that video of the guy with the AA batteries is absolutely bull shit.
The key was watching him hook the string up backwards at first.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

[bruce2...@gmail.com]

On Wednesday, April 10, 2019 at 7:03:23 AM UTC-4, pf...@aol.com wrote:
> Good cables are #4 copper.

Or with a greater diameter.

[tabb...@gmail.com]

On Friday, 12 April 2019 15:55:26 UTC+1, Fox's Mercantile wrote:
> On 4/12/19 9:48 AM, pf...@aol.com wrote:

> > Guys and gals: Give advice as if it were to a human being that you might possibly care about. And think about that advice as you give it. What you do for yourself and with only yourself at risk is fine. When you suggest that to another, own it and 100% of the potential consequences - even the possible limitations of the recipient.
>
> And that video of the guy with the AA batteries is absolutely bull shit.
> The key was watching him hook the string up backwards at first.

bzzt. Again. That's normal electroboom style.

[Fox's Mercantile]

Then that just means all his other videos are suspect.

[tabb...@gmail.com]

On Saturday, 13 April 2019 01:57:49 UTC+1, Fox's Mercantile wrote:

> On 4/12/19 5:16 PM, tabbypurr wrote:
> > On Friday, 12 April 2019 15:55:26 UTC+1, Fox's Mercantile wrote:
> >> On 4/12/19 9:48 AM, pf...@aol.com wrote:
> >
> >>> Guys and gals: Give advice as if it were to a human being that you might possibly care about. And think about that advice as you give it. What you do for yourself and with only yourself at risk is fine. When you suggest that to another, own it and 100% of the potential consequences - even the possible limitations of the recipient.
> >>
> >> And that video of the guy with the AA batteries is absolutely bull shit.
> >> The key was watching him hook the string up backwards at first.
> >
> > bzzt. Again. That's normal electroboom style.
> >
>
> Then that just means all his other videos are suspect.

yawn.

[et...@whidbey.com]

On Fri, 12 Apr 2019 19:57:41 -0500, Fox's Mercantile <jda...@att.net>
wrote:

Electroboom likes to poke fun at all the youtube videos that show
impossible stuff. Like perpetual motion videos. I'm sure what you saw
was tongue in cheek.
Eric