Don't jump start a bike off a car battery - Page 3

Nate · 07-26-2006

Older regulators (such as those found on KZ models) seem to be more susceptible to being burned out by jump starting. I suspect that they don't have much reverse voltage protection built in and even a fairly low (more than a few volts over nominal battery voltage) level reverse voltage spike can kill them. Even though the battery in a car does a good job of suppressing the alternator's spikes that get past the rectifiers, a failing alternator could put a few tens of volts of A/C on the car's DC system. This is probably enough to damage the older regulators.

Jumping a 12 volt bike from a car or pickup with a 12v system while its engine is off should pose no problem other than the usual precautions.

uechi kid · 07-28-2006

I jumped my Shadow a few times with a car. The car was off and never had any problems.

Xgenn · 07-31-2006

i have a portable jump pack and last year it worked great for jumping my bike.....

Xgenn

topcatflyer · 08-16-2006

amps will kill!!!

brotha_d · 08-16-2006

whatever happened to the old trusty pushstart?

Frankt07 · 08-16-2006

Quote:

Originally Posted by brotha_d

whatever happened to the old trusty pushstart?

ever try push starting a FI bike with a dead battery? good luck....lol

zedx11 · 08-16-2006

Quote:

Originally Posted by brotha_d

whatever happened to the old trusty pushstart?

ever tried to get a Kawasaki with positive neutral into any gear other than first?

*likearock4x4* · 08-17-2006

Quote:

Originally Posted by zedx11

ever tried to get a Kawasaki with positive neutral into any gear other than first?

Sure, just get her going down a hill, she'll go then.

Nate · 08-18-2006

Quote:

Originally Posted by topcatflyer

amps will kill!!!

Eh?

topcatflyer · 08-18-2006

voltage with out apms safe. voltage with amps will kill electrical stuff and by the way you also. electrical circuts are designed to run on specific amperage. over amperage is like over pressure on a pipe to much and bang. voltage by its self 30,000 to 50,000 volts won't kill you if its not being pushed by amperage. i.e. coil. jumping from a source that is pushing to much amperage can damage

*likearock4x4* · 08-18-2006

Quote:

Originally Posted by topcatflyer

voltage with out apms safe. voltage with amps will kill electrical stuff and by the way you also. electrical circuts are designed to run on specific amperage. over amperage is like over pressure on a pipe to much and bang. voltage by its self 30,000 to 50,000 volts won't kill you if its not being pushed by amperage. i.e. coil. jumping from a source that is pushing to much amperage can damage

Where did you get that circuits are designed to work on amps?? It has been my experience that circuits are designed to work on volts, and fuses/breakers are designed to work on amps. These fuses/breakers are in place specifically to protect any wiring that is involved from overheating and causing fires or plain burning into pieces. Breakers, at my work, are also used in conjunction with relays to protect personnel from faults which would cause a piece of equipment from blowing up.

olbooker · 08-20-2006

Enough already! It is basic Ohm's Law... If you have 12 volts and 1 ohm of circuit resistance, it will draw 12 amps. Doesn't matter if you have a 12 million amp supply... the circuit will ONLY draw 12 amps. You can't PUSH more amps into a circuit than it can draw!

The problems occur if the jump battery is connected incorrectly (ie: positive to negative, negative to positive.) Just a momentary contact will cause problems with cars as well as motorcycles. Can blow fuses, fuse links, and electronics.

Craig Barton · 08-20-2006

Quote:

Originally Posted by nwujames

<<CORRECTION>>Don't jump start your bike off of a car that's turned on - the amperage difference will fry your bike's battery, and maybe the electrical system too.

Was this the first time you had to replace the battery? If so it had a good life.

*likearock4x4* · 08-21-2006

Quote:

Originally Posted by olbooker

Enough already! It is basic Ohm's Law... If you have 12 volts and 1 ohm of circuit resistance, it will draw 12 amps. Doesn't matter if you have a 12 million amp supply... the circuit will ONLY draw 12 amps. You can't PUSH more amps into a circuit than it can draw!

The problems occur if the jump battery is connected incorrectly (ie: positive to negative, negative to positive.) Just a momentary contact will cause problems with cars as well as motorcycles. Can blow fuses, fuse links, and electronics.

My, my, my .... just a bit testy, are we??? What kind of amps would you get if you connected two bikes together in parallel and each one has a load of 3.2 ohms?

fastback · 08-21-2006

I just jump started my 81' CSR last weekend with a friends F-150. It wouldn't start while the truck was off so we turned the truck on. Worked fine. I suspect his truck batt was pretty weak. I knew it would work because I also had the opportunity to jump start my old Suzuki GS1000 with my wife's Grand Am and later, a wall charger. Yeah it was plugged into a wall socket. I checked the cross voltage while it was on and it was the same as a vehicle's 14V A/C. I don't see why it wouldn't be the same. It's less expensive to keep it all the same. Otherwise we'd all have the much better 24V systems in our vehicles.

olbooker · 08-21-2006

Quote:

Originally Posted by likearock4x4

My, my, my .... just a bit testy, are we??? What kind of amps would you get if you connected two bikes together in parallel and each one has a load of 3.2 ohms?

Hey, we can all have a bad day once in a while.

The two bikes loads connected in parallel would have a combined resistance of 1.6 ohms. Assuming a 12 volt supply, they would, combined, draw 7.5 amps or 3.75 amps each.

*likearock4x4* · 08-21-2006

Quote:

Originally Posted by fastback

I just jump started my 81' CSR last weekend with a friends F-150. It wouldn't start while the truck was off so we turned the truck on. Worked fine. I suspect his truck batt was pretty weak. I knew it would work because I also had the opportunity to jump start my old Suzuki GS1000 with my wife's Grand Am and later, a wall charger. Yeah it was plugged into a wall socket. I checked the cross voltage while it was on and it was the same as a vehicle's 14V A/C. I don't see why it wouldn't be the same. It's less expensive to keep it all the same. Otherwise we'd all have the much better 24V systems in our vehicles.

I certainly hope this is a typo.

*likearock4x4* · 08-21-2006

Quote:

Originally Posted by olbooker

Hey, we can all have a bad day once in a while.

The two bikes loads connected in parallel would have a combined resistance of 1.6 ohms. Assuming a 12 volt supply, they would, combined, draw 7.5 amps or 3.75 amps each.

What if you removed some accessories that were on one of the bikes and it had a modified load of 5.4 ohms?

(You know, of course, I'm only playing, and I already know the answers to these.)

Watson69 · 08-31-2006

A car battery has higher "cranking amps" even though both are 12 volts.

Certainly y'all are able to "roll start" yer rides? Or they too heavy?

GreenJello · 08-31-2006

Just gotta throw my two cents in. I had to get my bike jump started about 5 times in a row from cars. All had their engines running, no issues with the bike. If there is a problem, it's not showing up, knock on wood!

07-26-2006	#41 (permalink)
Nate KZ Kool! Forum Supporter Join Date: Oct 2004 Location: Marysville, KS Posts: 1,982	Older regulators (such as those found on KZ models) seem to be more susceptible to being burned out by jump starting. I suspect that they don't have much reverse voltage protection built in and even a fairly low (more than a few volts over nominal battery voltage) level reverse voltage spike can kill them. Even though the battery in a car does a good job of suppressing the alternator's spikes that get past the rectifiers, a failing alternator could put a few tens of volts of A/C on the car's DC system. This is probably enough to damage the older regulators. Jumping a 12 volt bike from a car or pickup with a 12v system while its engine is off should pose no problem other than the usual precautions. __________________ "Riding is the reward for time spent wrenching." "Wrenching is the result of time spent riding!" KZ650 SR

07-28-2006	#42 (permalink)
uechi kid Forum Supporter Forum Supporter Join Date: Oct 2005 Location: Antioch, Ca. Posts: 1,773	I jumped my Shadow a few times with a car. The car was off and never had any problems. __________________ "Carpe Diem"

07-31-2006	#43 (permalink)
Xgenn Who Likes The Skippy?? Forum Supporter Join Date: Aug 2005 Location: Milwaukee Posts: 601	i have a portable jump pack and last year it worked great for jumping my bike..... Xgenn __________________ 86 Concours 1000 GTR http://www.myspace.com/xgenn

08-31-2006	#60 (permalink)
GreenJello Neuromancer Lvl 13 BTK Expert Join Date: Jul 2006 Location: Cincinnati, Ohio Posts: 519	Just gotta throw my two cents in. I had to get my bike jump started about 5 times in a row from cars. All had their engines running, no issues with the bike. If there is a problem, it's not showing up, knock on wood! __________________ The only valid censorship of ideas is the right of people not to listen. ~Tommy Smothers

08-16-2006	#44 (permalink)
topcatflyer topcatflyer Forum Supporter Join Date: Jun 2006 Location: Lake City, Michigan Posts: 213	amps will kill!!!

08-16-2006	#45 (permalink)
brotha_d Newbie Join Date: May 2006 Posts: 3	whatever happened to the old trusty pushstart?

08-18-2006	#50 (permalink)
topcatflyer topcatflyer Forum Supporter Join Date: Jun 2006 Location: Lake City, Michigan Posts: 213	voltage with out apms safe. voltage with amps will kill electrical stuff and by the way you also. electrical circuts are designed to run on specific amperage. over amperage is like over pressure on a pipe to much and bang. voltage by its self 30,000 to 50,000 volts won't kill you if its not being pushed by amperage. i.e. coil. jumping from a source that is pushing to much amperage can damage

08-20-2006	#52 (permalink)
olbooker Forum Supporter Forum Supporter Join Date: May 2006 Location: NE AZ Posts: 104	Enough already! It is basic Ohm's Law... If you have 12 volts and 1 ohm of circuit resistance, it will draw 12 amps. Doesn't matter if you have a 12 million amp supply... the circuit will ONLY draw 12 amps. You can't PUSH more amps into a circuit than it can draw! The problems occur if the jump battery is connected incorrectly (ie: positive to negative, negative to positive.) Just a momentary contact will cause problems with cars as well as motorcycles. Can blow fuses, fuse links, and electronics.

08-21-2006	#55 (permalink)
fastback Fastback BTK Expert Join Date: Aug 2006 Location: Virginia Posts: 289	I just jump started my 81' CSR last weekend with a friends F-150. It wouldn't start while the truck was off so we turned the truck on. Worked fine. I suspect his truck batt was pretty weak. I knew it would work because I also had the opportunity to jump start my old Suzuki GS1000 with my wife's Grand Am and later, a wall charger. Yeah it was plugged into a wall socket. I checked the cross voltage while it was on and it was the same as a vehicle's 14V A/C. I don't see why it wouldn't be the same. It's less expensive to keep it all the same. Otherwise we'd all have the much better 24V systems in our vehicles.

08-31-2006	#59 (permalink)
Watson69 2000 ZX-6 BTK Beginner Join Date: Aug 2006 Location: Atlanta, GA Posts: 53	A car battery has higher "cranking amps" even though both are 12 volts. Certainly y'all are able to "roll start" yer rides? Or they too heavy?

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