Have you replaced your battery with a new fresh one, just to come out the next day to a vehicle that still refuses to start? If this annoying situation has happened to you, chances are your problem was not the battery at all, but stems from your Jaguar alternator. Even the best battery cannot hold its charge for long if the Jaguar alternator is not recharging its supply of power. Your vehicle needs a lot of electrical energy every day to run a number of crucial systems. There is the vehicle computer, drawing power constantly as it monitors and adjusts a variety of vehicle operations. There is the engine-cooling fan keeping your engine within a safe operating temperature. Your lighting system draws quite a bit of power as well, along with many other necessary systems that need electrical power to function. With no charging power coming from the Jaguar alternator, your battery doesn't stand a chance at keeping up with that power demand, let alone the power drawn for the non-essential accessories, like the radio and air conditioner fan. Your Jaguar alternator works hard to supply that power demand every minute that the vehicle is running, even just at idle. The charging process uses the mechanical energy of the turning crankshaft, transmitted by a serpentine belt, to turn the Jaguar alternator, which then uses that mechanical energy to produce voltage that once channeled through diodes is used to charge the battery. If your Jaguar alternator has failed, we carry a selection of quality replacements in our online catalog, all at great prices. Ordering is always a breeze on our secure site, or our toll-free phone line can take your Jaguar alternator order just as conveniently.