More jumping batteries

Rsv1000R · 03-23-2009, 03:23 PM

I've thought of a way you might fry your bikes electronics while jumping the bike, and jumping it from a car could increase the chance of it happening. And figured it deserved a separate thread, as opposed to hijacking the other thread again.

There's 2 parts of this, couldn't tell you if effect is actually strong enough, unless you take what zed's seen working on bikes.

So if you take a long cable, it starts looking inductive, batteries look a bit like capacitors. Connecting the last cable up can spark, and that could cause come ringing, and could cause a voltage spike.

The other effect, is if you dump a lot of current through a long cable it'll create a magnetic field, and when the current drops, will collapse, making a voltage spike.

I also know that for instance cmos ic's, when an input or output is pulled to a higher voltage than supply can inject current into a parasitic scr, and if it turns on, will short the supply until power's removed or something burns out.

Now I suspect a fully charged motorcycle battery, would do the same thing, But it is working with 1/2-1/4th the current into a completely dead battery a car battery could provide.

03-23-2009, 03:23 PM	#1
Rsv1000R WERA White Plate Join Date: Nov 2008 Posts: 1,059	More jumping batteries I've thought of a way you might fry your bikes electronics while jumping the bike, and jumping it from a car could increase the chance of it happening. And figured it deserved a separate thread, as opposed to hijacking the other thread again. There's 2 parts of this, couldn't tell you if effect is actually strong enough, unless you take what zed's seen working on bikes. So if you take a long cable, it starts looking inductive, batteries look a bit like capacitors. Connecting the last cable up can spark, and that could cause come ringing, and could cause a voltage spike. The other effect, is if you dump a lot of current through a long cable it'll create a magnetic field, and when the current drops, will collapse, making a voltage spike. I also know that for instance cmos ic's, when an input or output is pulled to a higher voltage than supply can inject current into a parasitic scr, and if it turns on, will short the supply until power's removed or something burns out. Now I suspect a fully charged motorcycle battery, would do the same thing, But it is working with 1/2-1/4th the current into a completely dead battery a car battery could provide.