Battery Care And Maintenance; Charge Rate; Bulk Voltage; Float Voltage - Xantrex7 UX - REV A Owner's Manual

Appendix B - Batteries

Battery Care and Maintenance

NOTE: The UX inverter/charger does
not have adequate voltage to
equalize-charge batteries. If
using batteries requiring
occasional equalization, a
separate charger will be
required.

Charge Rate

NOTE: The UX inverter/charger does
not have flexible charge
settings. Please refer to
Appendix A - Specifications
for actual charge rates.

Bulk Voltage

Float Voltage

Temperature Compensation

Equalization Charging

CAUTION: Because a higher
voltage is used to equalize-
charge the batteries, any DC
loads must be disconnected
before an equalization-
charge is started.
CAUTION: Equalization
should be done for standard
electrolyte vented batteries
only. Sealed or gel cell
batteries should not be
equalize charged. Consult
your battery supplier for
details.
B-16
To get the best performance from an inverter system, the batteries must be
properly setup and maintained. This includes setting the proper voltages for
Bulk and Float charging. On a monthly basis, the batteries should be "Equalize-
charged" (vented batteries only) and the water level checked and maintained
(See the "CAUTIONS" in the section on equalization charging below). In
addition, the battery terminals should be inspected, cleaned, and re-torqued,
if necessary.
Neglecting any of these items may result in poor inverter performance and
greatly reduce battery life.
The maximum, safe charge rate is related to the size and type of the batteries.
Standard, vented, lead acid batteries (with removable caps) can be charged at a
high rate, equal to their capacity. Small batteries may require a lower charge
rate. Check with your battery manufacturer for the proper battery charging rate
for the batteries used in the system.
This is the maximum voltage the batteries will be charged to during a normal
charge cycle. Gel cell batteries are set to a lower value and non-sealed batteries
are set to a higher voltage setting.
The float voltage is set lower than the bulk voltage and provides a maintenance
charge on the batteries to keep them in a ready state.
For optimal battery charging, the bulk and float charge rates should be adjusted
according to the temperature of the battery. This can be accomplished
automatically by using a Battery Temperature Sensor (BTS). The sensor attaches
directly to the side of one of the batteries in the bank and provides precise
battery temperature information.
See Section 1, page 2, for information on the Xantrex Battery Temperature
Sensor (BTS).
Every month or two the batteries should be equalize-charged. This helps to
remove sulfate buildup on the battery plates and balances the charge of
individual cells. Batteries that are not equalize-charged can be damaged by
sulfate accumulation, thus sealing off a percentage of the plates and reducing
battery capacity.
Equalize-charging also produces gassing which stirs up the electrolyte mixture
and helps distribute the acid more evenly. Batteries that are not equalize-
charged may have sulfuric acid accumulate at the bottom of the battery,
potentially damaging the plates. At the same time, the electrolyte at the top of
the battery gets watery. This is called stratification.
©2002 Xantrex Technology Inc. All Rights Reserved.
P/N 975-0026-01-01 Rev A 06/2002