How car jump starters work?

[siliconmike]

I would like to know how those commercially available jump starters
provide hundreds of cranking amperes to start cars?

Simply, what is the electronics behind this?

Here is an example jump starter:
http://automotive.hardwarestore.com/11-16-battery-jumper-cables/vector-jump-start-system-100762.aspx

Any explanation / hint would be very much appreciated.

Thanks,
Mike

 

[Phil Allison]

** Another Groper ......

I would like to know how those commercially available jump starters
provide hundreds of cranking amperes to start cars?

Simply, what is the electronics behind this?

Here is an example jump starter:
http://automotive.hardwarestore.com/11-16-battery-jumper-cables/vector-jump-start-system-100762.aspx

Any explanation / hint would be very much appreciated.

** It weighs 20 pounds .

It comes with a charger.....

Hint , hint ????




......... Phil

 

[Joel Kolstad]

I would like to know how those commercially available jump starters
provide hundreds of cranking amperes to start cars?

They have a battery inside of them! A brick-sized battery can easily provide
100 amps for a little while (typically it'd be something like a 12V, 2Ah
battery, which will provide 100A for about 1 minute... and that's only if the
car's battery is completely dead).

Simply, what is the electronics behind this?

I've never taken one apart, but I believe it's just some simple charging
circuit and probably a good-sized Schottky diode to prevent incorrect hookup.

 

[Phil Allison]

"Joel Kolstad"

They have a battery inside of them! A brick-sized battery can easily
provide 100 amps for a little while (typically it'd be something like a
12V, 2Ah battery, which will provide 100A for about 1 minute... and that's
only if the car's battery is completely dead).

** From the size and weight ( 21 pounds) of the unit, SLA battery of about
18 AH is more likely.

http://www.batterywholesale.com/battery-store/proddetail.html?prodID=377


At circa $31 it comes well within the cost too.




........ Phil

 

[Stanislaw Flatto]

I would like to know how those commercially available jump starters
provide hundreds of cranking amperes to start cars?

Simply, what is the electronics behind this?

Here is an example jump starter:
http://automotive.hardwarestore.com/11-16-battery-jumper-cables/vector-jump-start-system-100762.aspx

Any explanation / hint would be very much appreciated.

Thanks,
Mike

Hint - a well charged battery, for the few seconds till the motor starts
(or NOT). Won't work if your original battery developed a short!

Stanislaw
Slack user from Ulladulla.

 

[[email protected]]

I've never taken one apart, but I believe it's just some simple charging
circuit and probably a good-sized Schottky diode to prevent incorrect hookup.

The battery is connected directly to the outside world on the alligator
clips; you connect it up wrong, you fry...

The complexity of the charge circuit depends on the product model. Some
of them have a simple LED state-of-charge indicator and these models
tend to have slightly more complex charge circuits. These products are
designed to be plugged into AC longterm, and as such they are float
charge circuits - typically an adjustable regulator (TO-220 package,
like an LM317) and a current-limiting resistor.

 

[John - KD5YI]

I've never taken one apart, but I believe it's just some simple charging
circuit and probably a good-sized Schottky diode to prevent incorrect hookup.

A diode can't prevent incorrect hookup.

 

[Spehro Pefhany]

A diode can't prevent incorrect hookup.

Four can.


Best regards,
Spehro Pefhany

 

[Jim Thompson]

Four can.


Best regards,
Spehro Pefhany

Or some variation of....

http://analog-innovations.com/SED/PerfectDiodeForChargerIsolation.pdf

or

http://analog-innovations.com/SED/OverAndReverseVoltageProtection.pdf

...Jim Thompson