Car vs Bike Battery

[Top Cat]

I was reading bernsax thread on dead batteries and didn't want to highjack his thread Soooooooooooo, Why is it a car with a dead battry will jump start and run and a bike will jump start and not run?

[AlabamaNomadRider]

Tim I just covered that in his thread. I have done that many times with cars. I think the alternator in a car puts out enough volts to run the car. Where the bikes alternator doesn't put out enough to do the same thing. Heck the bike alternator doesn't even put out enough volts to keep the battery fully charged.

[Top Cat]

Sorry Gene , Didn't see your answer. Thanks.

[AlabamaNomadRider]

Not a problem Tim, didn't mean you should have seen it. I sent you a PM explaining it. Just try to help as much as my feeble brain will allow.

[usranger74]

Originally Posted by AlabamaNomadRider

Tim I just covered that in his thread. I have done that many times with cars. I think the alternator in a car puts out enough volts to run the car. Where the bikes alternator doesn't put out enough to do the same thing. Heck the bike alternator doesn't even put out enough volts to keep the battery fully charged.

If this were the case, would not the battery run down on a long ride?

[skiman]

I have a project bike I jump start all the time runs just fine
Do you mean push starting or using jumper cables

[blowndodge]

TC. Some cars and bikes can be jumped but not stay lit because of how the engines are set up. a dirt bike for example has no battery but runs it's electrics off of a magneto.

It all depends how the manufactures set up the charging system. Nowadays electronic fuel pumps, ECU's and other electronic gizmos hooked to the operation of the vehicle need a constant electrical supply or once you unhook the battery jumper cables they will quit, killing the engine..

[Top Cat]

I was just curious. Thanks BD. I had a 650 Yamaha back years ago and on the way home from Americade it just quit. My brother and I finaly figured out the positive cable on the battery came loose. tightened it back up and all was good.
I have always been quite a good mechanic. :-[

[macmac]

I think in that case the battery was dead shorted. Once a Nomad is running even with a pretty bad battery it should stay running, but nothing will with a dead shorted battery, and that can cook the alt in anything but fast!

The alt and regulators see that as go to FULL blast charge and that cooks the alt and the regulator.

Nomads will put out 40 amps, which is plenty almost twice what any other bike does, except BMW and Gold Wing, and other belt driven alt bikes if there are any.

When I saw GW, I mean Valks too since they share the same engines and charging systems.

A nomad will charge at idle. It will charge really high at idle too. 14.8 to 15.2 which is real high.

When I run the pair of passing lamps (2) at 55 watts each, almost a 10 amp load, I read 13.8 to 14.00 dcv volts at 2,500 RPM, which is very good.

My passing lamps are on a dedicated circuit just made for them and switched with no relay. This set feeds straight off the battery and is fused.

My volt meter is fed off the acc wire. The meter checks out with 2 vom's, so I know my readings are accurate.

On a ride where i went somewhere, at I pull in near to home a mile or 2 out maybe i turn off the passing lamps, and when I get home I idle the engine a moment parking and will see readings in the low 15's often at 950 rpm.

My 01 1500 did that same thing too, so it isn't just my 06 is fluky.

We have a twin stator charging system unlike any other kind of motorcycle there IS. It is much more like a air plane charging system than anything else.

There are 2 regulator rectifiers and 18 bloomin diodes. Unlike anything I ever saw not on an air plane.

Evidently the rec/regs put out 7.0 / 7.5 volts dc on the fields, or this couldn't happen in the first place. I have never tested the fields, but have on other cars, trucks, and bikes.

I KNOW the field voltage is 1/2 the out put voltage, and how if creates AC volts more than double 14 dcv.

That old 650 yammi was kickin out apx 36 acv, some loss in the heat sinking and in the wires on the ac side created about 14.4 dcv when all was said and done, to apx 20 amps, Half what a nomad makes.

How I know that is with a lot of testing on a 850 yammi which has the exact same chrg sys as the 650.

I had a dead shorted stator on my 850 and that stator is still in the engine today and works fine. It is a real odd problem and I had to spend time sorting it out. Since then I bought a whole and 1/2 charging system as spares.

I know ever wire in that system and how the whole bloomin thing works.

That system mimics a great deal of other systems made in a like mannor. There is a stator outside a crank shaft mounted iron rotor. Inside that is the field coil, with a brown 12+ battery wire, a green 1/2 battery field wire regulated by the rec/rec, and a black ground.

On what happens is a electric field passes thru vent like openings in the spinning iron rotor, and as this field is opened and closed AC power is generated in each of 3 pair of off white wires. Each pair is 1/3rd of 36 ACV.

That ACV current is sent to the rectifier, where 1/2 the AC power is sent to heat sink off, and the diodes allow the other 1/2 of the power to pass back to the battery and feed the bike.

There are no carbon brushes, no magnetos, on either of the yamii or nomads we are speaking of here.

I can and have workled with them too, but that's another thread.

[ringadingh]

Ive jumped mine in the past and its stays running, although I had to keep it at a fast idle for about five minutes. I think if your battery is totally dead or shorted and won't accept any sort of charge, you may find that it won't stay running.