Charging Batteries
The batteries can be charged by using good quality AC powered battery charger or
from alternative energy sources like solar panels, wind or hydro systems. Make sure
an appropriate battery charge controller is used. It is recommended that the batteries
may be charged at 10% to 13 % of the Ampere Hour capacity (20 hour discharge
rate). Also, for complete charging (return of 100 % capacity ), it is recommended that
a 3 stage charger may be used (Constant current bulk charging followed by constant
voltage boost / absorption charging followed by constant voltage float charging )
Batteries, alternators and isolators on vehicles / RVs
It is recommended that for powering the inverter, one or more auxiliary deep cycle
batteries should be used that are separate from the SLI battery. The inverter should
be powered from the deep cycle batteries. For charging the SLI and the auxiliary
deep cycle batteries, the output from the alternator should be fed to these two sets
of batteries through a battery isolator of appropriate capacity. The battery isolator
is a device that will allow the alternator to charge the two sets of batteries when
the engine is running. The isolator will allow the inverter to be operated from the
auxiliary batteries and also prevent the SLI battery from charging the auxiliary deep
cycle batteries when the engine is not running. Battery isolators are available from
auto / RV / marine parts suppliers
A majority of smaller vehicles have 40 to 105 Ampere alternator and RVs have 100
to 130 Ampere alternator. When in use, the alternators heat up and their output
current capacity can drop by up to 25%. When heated up, their charging voltage may
also not reach the desired absorption voltage and will result in return of only about
80% of the battery capacity. In case the current output of the standard alternator is
not adequate to charge the two sets of batteries rapidly and fully to 100% of their
capacity, use heavy duty alternator that can produce higher current and voltage
required to charge multiple battery systems. These alternators are available with auto
/ RV parts suppliers.
Page18
