I know guys on the auto drag racing circuit that use motorcycle batteries because they are smaller and lighter. Motorcycle batteries are capable of cranking big block, high compression motors. The difference between the 2 is reserve capacity. Some large car batteries will keep a vehicle running for 90 minutes or longer while a motorcycle battery will only last 15 to 20 minutes.chuckM said:I agree with all of the above...it wouldn't take much from a car battery to start the bike. The car not running is certainly safer.
"Tiny" battery...you ought to see the 6v Triumph's...
I thought a voltage regulator just kept the running voltage at about 14.6 volts, more or less. Does that mean if I increase the load, like turn on more lights and hook up electric clothes, etc, that I will inrease the voltage out of the regulator? I had always figured the increased power came from added amperage.If you leave the vehicle running, when you connect it to the bike, the running vehicle's voltage regulator will sense the added load, and increase voltage coming from the alternator to cover the load.
I don't understand your reasoning. And besides, it can't provide more voltage... current yes, voltage, no. Why would the running battery supply more current? It will only supply enough current to cover the load, i.e., lights and starter. Since the motorcycle battery can provide much more current than that, IMO, it won't "hurt" the smaller battery in the least.Fred H. said:If you leave the vehicle running, when you connect it to the bike, the running vehicle's voltage regulator will sense the added load, and increase voltage coming from the alternator to cover the load. This increased voltage can cause enough current to get pushed through your tiny motorcycle battery to damage the plates in it. The higher voltage *could also potentially damage your starter motor if it got high enough (*though it is doubtful it would get that high).