Xantrex Technology 2500 - Manual (Page 14)

90-0115-00
10/97 Fltman.pm65
BATTERIES
Always use proper terminals for your
interconnecting battery cables which are
appropriate to handle the current.
Battery Bank Ratings and Sizing
Deep-cycle batteries are usually rated
in Amp-hours. The Amp-hour rating is
based on a 20 hour discharge cycle, there-
fore, a 100 Amp-hour battery can deliver 5
Amps for 20 hours. If the discharge rate is
greater than 5 Amps, the available Amp-
hours are decreased. If the load is in-
creased to 100 Amps, only about 45 Amp-
hours will be available at this rate of dis-
charge.
Another common rating is reserve
capacity expressed in minutes. This is
derived by placing a 25 Amp load on the
battery and measuring the time until the
battery voltage reaches 10.5 Volts.
Deep-cycle batteries can be discharged
about 80% before permanent damage
occurs, though shallower cycling will result
in much longer battery life. 50% cycling is
generally considered to be a good compro-
mise between long battery life and a rea-
sonably sized battery bank.
Parallel
Connecting 2 batteries in parallel will
double the Amp-hour rating of the battery
bank, while the voltage will be the same as
each individual battery. Example, two 12
Volt 105 Amp-hour batteries in parallel will
produce one 12 Volt 210 Amp-hour battery
bank.
+
+
-
-
Only similar batteries should be
connected together in one bank. Do not
connect old and new batteries together or
wet and gel cell batteries together. In the
above drawing, the load is connected to the
positive terminal of the first battery and the
negative terminal of the last battery. This
practice helps to balance the battery bank
and is called cross connecting the battery
bank.
Parallel
14