Xantrex Technology PROwatt 600 - Manual (Page 53)

Charging System Requirements
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Charging System Requirements
Your charging system should be capable of delivering a
charging current equal to 10–25% of the amp-hour capacity
of your battery. For example, if you have a 200 Ah battery,
the charging system should be able to deliver 50 amps. The
charging system must also be able to charge each 12 volt
battery up to approximately 14.4 V and then drop back to a
“float” voltage of 13.5–14 V (or shut off).
Charging With an Engine Alternator
The following information will let you 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 Your Vehicle’s Standard Engine Alternator
A typical engine alternator (12 volts) may not be able to meet
these requirements if your system uses large capacity
batteries. Alternators are typically rated for the current they
can deliver when they are cold. In use, alternators heat up,
and their output current capability drops by as much as 25%.
Therefore, standard alternators with ratings of 40–105 A will
only deliver a maximum of 30–80 A in actual use and will
deliver even less as battery voltage rises. Many alternators
cannot produce more than 13.6 V 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.
CAUTION
Never operate the PROwatt 600 directly from an
alternator. To work properly the PROwatt must be
connected to a battery or a well-regulated, high-
current DC power supply.