Originally Posted by sartek
One of the local yamaha dealers here in town told me to never jumpstart a bike direct from a car battery, but instead to plug into the 12v/ cigarette lighter because they are commonly fused at 5 or 10 amps and it adds an extra level of safety for the bike.
I suspect that even a 5 to 10 amp fuse would blow when starting a Versys unless you first let the Versys battery charge for many minutes. In that case most of the starting current would come from the Versys battery, and only a lower sub 5-10 amp current from the other vehicles battery. I wouldn't worry about protecting the other vehicle by using a fused circuit.
I also take issue with the jump starting procedure in tenover's
post. Here's how it should be done in cars, and I believe, in motorcycles as well: (I'll explain my reasoning after the procedure.)
1. Attach one end of the red cable to the dead battery's positive terminal.
2. Attach the other end of the same red cable to the positive terminal of the battery in the starting vehicle.
3. Attach one end of the black cable to the negative terminal of the battery in the starting vehicle.
4. Attach the other end of that black cable to the engine block of the car with the dead battery. Look for unpainted metal surfaces and be sure it will clear anything moving when the car starts. Do not attach the negative cable to the dead battery itself.
5. Start the car. (Or motorcycle.)
6. Remove the cable connections in the reverse order that you put them on. That means that the first disconnection is from the block, and the last is from the positive terminal of the car that has just been started.
The reason you don't connect the black cable to the dead vehicles negative terminal is that the dead battery when charging will give off hydrogen gas. This is true for all lead acid batteries including gel and glass mat batteries which are now common in motorcycles. If you spark the cable, especially during removal when the jump started battery has charged for some time, the risk is greater.
On our motorcycles it's tough to connect a lead to the "block" because the engine is painted. You can usually find some unpainted ground connection that will work and carry enough current to start the bike.
The last issue is whether it's safe to jump start a bike from a car.
Originally Posted by tenover
The procedure to jump start a motorcycle from a car is the same as it is for jump starting it from another motorcycle except for item (6). A car battery has more amperage, and the charging system for a car is much more powerful than that of a motorcycle. When jump starting a motorcycle from a car, DO NOT START THE CAR'S MOTOR because the extra power from the charging system will possibly destroy the motorcycle's charging system and could cause a fire. The car battery should have enough power to start the motorcycle without the car's motor running.
I think the issue of having the cars engine running or not is not important. Sure, a cars charging system is much more powerful than a bike's. But the voltage is regulated the the same 14ish volts as a bikes. I can't see how a running car would provide a dangerous amount of power to the bike when a fully charged car battery in a non running car would not. The issue here could be that the bikes battery is so dead that connecting it to a high current 12 volt source (car battery in a non running car) or 14 volt source (car battery in a car with the engine running) delivers a high enough current to hurt the bike battery.
In the case of a totally dead battery the safest route would be to use a battery charger designed for motorcycle batteries.
Having said that I will add that I have successfully started bikes with totally dead batteries from cars. I just don't connect the black jumper cable to the negative terminal on the battery, and I let the battery charge for 5 to 10 minutes before attempting to start the bike.