jump start

[Anonymous]

My bike (80GS450) is been sitting for about a week, and the battery is dead, can I jump start it with my car and go?, and why is this battery dead in a week or so, is this a sign of problems with the charging system?.
Thanks in advance.

[tfb]

UnderDog,

I'm not sure if jump-starting it from a car battery is a good idea (but rest assured that before too long some good GS-er who knows for sure will chime in and give us all the good oil).

But I can say this about your battery:

1. It could well be stuffed. Run some tests, eg. give it a charge, and then use a hydrometer (or should that be hygrometer?) to determine the specific gravity of the acid.

2. You could have leakage somewhere in the bike's circuitry. Commonly, this is in the reg/rect. unit, when some of the diodes blow and you get current leaking back through the unit from the battery to earth. If this is the bit that's responsible, you'll have to replace it.

3. Or, your charging system is stuffed. Check the output from your alternator. You could be up for a new stator and/or reg/rectifier.

The best way forward, is use the trouble-shooting info. in 'The Stator Papers' on the GS Resources website here.

Happy hunting,
Mike.

[jimcor]

Don't jump it from your car.

Your bike's charging system will not recharge a dead battery.

You'll have to use a charger of 2 amps or less to recharge a dead battery, it will take about 12 hours or overnight if the battery is completely discharged.

[fgh]

Good or bad I jump from a car but under no circumstances is the car running. I've done it several times with no apparent problems. If the car were running it would attempt to charge the motorcycle battery far to quickly.

[KennyJ]

The biggest problem is running your starter too long and burning it up. A car battery can really spin it for a long time, which the bike battery can't. Just crank it in 3 second or so intervals (with 10seconds or so between_ and if it doesn't start after 8 tries or so, let it cool for a few minutes and try again.

I would start from a non-running car, but I don't see the issue as others do.

Kenny

[kalessin]

I have also jumpstarted my GS a number of times from a car battery but, as has been mentioned, never with the car's engine running.

A "smart" motorcycle battery charger -- Deltran Battery Tender is my favorite -- is the best way to charge the battery (when you're not riding), and to store it if you don't have a year-round riding season.

The quick way to test a battery is to test it under load. Charge it up using a battery charger, and test it with the bike turned on ("under load") but not running. It should read 12.6 volts or so. Down around 9 volts or less, and the battery is toast.

Use the test plan in the Stator Papers on the main GSResources site to diagnose the charging system:

http://www.thegsresources.com/gs_garage.htm

[jimcor]

It's a voltage issue folks.

It has nothing to do with a battery charging too fast.

And the reason that starter is spinning like crazy is your car battery has more voltage on tap than your bike's battery. You bet the starter will get hot and so will every other component of your electrical system. Earl explained this in another jump start thread some time ago, with all the values and technicalities. The bottom line is don't do it. You risk, literally, frying your system.

[fastpakr]

You mean amperage? I'm not well versed on the electrical side, but I assumed since they were both 12 volt systems that the voltage through the starting circuit would be the same if you jumpstarted.

[jimcor]

No, I mean voltage. Go put the multimeter on the car battery. Bet you'll get a reading closer to 14 volts than 12. Then check your bike battery. 12 and a half maybe a little more.

12 volts is the nominal system value. It is the voltage components are rated at. However they will operate at a +/- range of voltage. Your car is heavy duty, no, Heavy Duty compared to your bike.

[gspaul]

12v battery from a car can be used,the starter will only take what it needs.

[SqDancerLynn1]

12 volts is 12 volts so go ahead & jump it DO NOT have the car running
A car alt puts out 60-100 amps That will kill it.
Your battery should stay charged for weeks. You could have a bad battery or their could be a drain on the system. I have a radio on my 850 with digital display/clock IF i leave it hooked up It will drain the battery in a week

[Steve]

Yes, a car alternator can put out 60-100 amps, but only if there is somewhere for it to go. The problem with jumping a bike from a running car is that the rectifier/regulator will try to regulate the output from the car's alternator. THAT is where the 60-100 amps will go, and the regulator will toast itself trying to handle the load.

Go ahead, use ANY 12 volt battery to start your bike. Just make sure the vehicle it's attached to is NOT running.

By the way, you MIGHT have problems with the charging system, and you MIGHT have a bad battery. How old is the battery? If you have a minimal charging system and the battery is more than two years old, replace the battery. Charge it before you install it in the bike, though. No sense in making your bike do all the work. With a properly operating charging system and attention to water level, you should get about 4 years out of a battery.

[Anonymous]

jump start

Thanks for all you replies, I'll jump start it from my car, then take the battery to have it check, to see if it's still good. I will also check for any bad wires.

[earlfor]

Thats it in a nutshell. Regardless of battery capacity available, the starter will only draw what it needs, which will be the same amperage whether from a bike battery or a car battery. Extended cranking can overheat the starter motor, but that can happen with either battery. When two batteries are jumped, electrically, they are one battery. With a car running, you will have two charging systems charging a single battery. The car alternator will overpower the bike's R/R which is trying to regulate the circuit. The bike loses. Fried bike. In marine applications, you will never see engine charging systems that charge the same battery from from multiple alternators. There is always a switching system that will not allow you to switch two alternators online simultaneously to charge the same battery.
There is a reason for that. :-)

Earl

[quote="Steve"]
Yes, a car alternator can put out 60-100 amps, but only if there is somewhere for it to go. The problem with jumping a bike from a running car is that the rectifier/regulator will try to regulate the output from the car's alternator. THAT is where the 60-100 amps will go, and the regulator will toast itself trying to handle the load.

[Steve]

Earl,

Interesting side note here...my '84 Kawasaki Voyager 1300 has two stators, two R/Rs and one battery. I am guessing that since they are similar charging systems, they don't overpower each other.

The reason for two systems: When the bike was introduced in 1979 as the KZ1300, it had a minimal (237 watt) charging system. Apparently the designers did not figure in what the Americans were going to do to this bike by adding fairing, luggage, lights, etc. In 1980, output was upped to 258. For 1981 and 1982, it went to about 300. The bike was redesigned for 1983 and came out fully-dressed as the Voyager. Since electronic fuel injection was added, there was more drain on the charging system. The solution was to replace the harmonic balancer on the other end of the crankshaft with another rotor and stator with about 200 watt capacity.