Re: big problem with my xfire, please help
The way I see it and I may be completely wrong is that the battery buffers the voltage from the alternator which puts out a varying voltage. The problems arise with the voltage swings between the high of the regulator and the low put out by the failing battery, the voltage swing is what causes the problems.
The alternator puts out an AC voltage and the regulator only uses a portion of that, in essence only using flashes of some of the voltage output on the positive side of the curve.
The result being that the voltage available is a high of 13.8 V from the alternator and a ideal low of 12.8 V from the battery with the battery buffering this to a more uniform voltage.
When the battery is failing the swing would be higher, and this would create the problems. Some systems I suspect can work well on a greater voltage swing but others cannot.
The battery stores power, if you had a setup whereby you tried to start your car from the alternator alone it would not have anywhere near enough power to turn the starter motor, the battery stores power and is capable of releasing it in an instant. The alternator takes some time to replenish this power, but the battery can store enough to use the starter time and time again.
The amount of power that the battery stores is dependent on the number of plates in it, less plates in each of the six cells gives greater storage but less cold cranking amperage. More plates in each cell gives a higher cold cranking amperage but will get flat quicker due to less power storage.
I'm sure there are whiz kids who can rip apart my ideas, so go ahead please, I'm always willing to learn. If my errors are corrected then we all can learn.
Last edited by onehundred80; Nov 2, 2010 at 11:40 AM.