Xantrex Technology XM 1000 Charging With an Engine Alternator, Using a High-Output Alternator

Alternators and Charging Systems

Charging With an Engine Alternator

Read the following information to determine whether your vehicle’s standard alternator will be adequate by itself, whether you should install an alternator controller, or whether you need a high-output alternator.

Using a Standard Vehicle Alternator

A typical engine alternator (12 volts) may not be able to meet the requirements outlined above if your system uses large capacity batteries. Alternators are typically rated for the current they can deliver when they are cold. When in use, alternators heat up, and their output current capability drops by as much as 25 percent. Therefore, standard alternators with ratings of 40 to 105 amps only deliver a maximum of 30 to 80 amps in actual use and deliver even less as battery voltage rises. Many alternators cannot produce more than 13.6 volts when they are hot. As a result, a standard alternator may not be able to charge a large battery quickly and completely.

Two solutions are to install an alternator controller or to install a high- output alternator.

Using a Multi-stage Alternator Regulator

If your existing alternator charger is inadequate, you should consider installing a multi-stage alternator regulator. This will maximize the alternator’s charging rate without exceeding proper battery charge voltages and ensure more rapid and complete charging.

Multi-stage alternator regulators, such as the Xantrex Alternator Regulator (XAR), are available from marine product dealers.

Using a High-Output Alternator

If the alternator charging is still inadequate after installing the XAR, heavy-duty alternators rated from 100 to 140 amps can replace standard alternators and produce the higher current required to charge multiple battery systems. They are available from RV and marine dealers, as well as auto parts suppliers.

C–2 975-0263-01-01