Xantrex Technology RS3000 - Manual (Page 107)

Battery Charging Reference
975-0170-01-01 B–3
There is a fourth stage, equalization, which is initialized manually as it is
only performed occasionally and only on flooded (or wet) batteries.
Bulk Charge
In the first stage—the bulk charge—RS3000 delivers its full-rated output
current. This constant current is delivered to the batteries until the battery
voltage approaches its gassing voltage—typically around 13.5 volts for
12 volt batteries. The bulk charge stage restores about 75% of the
battery’s charge.
The exit from bulk stage to the next stage, absorption, occurs under the
following condition:
• battery voltage is more than the gassing voltage (V
G
) for a specified
amount of time (3 minute default).
With an AC reconnect to qualified AC from the utility power or a
generator during the bulk stage, the unit will return to the bulk stage.
Absorption Charge
During the first part of absorption charge, the RS3000 delivers its full
rated output current until the absorption voltage is reached. At this point,
the RS3000 will transition to a constant voltage mode by keeping the
charge voltage constant at the absorption voltage level, and the battery
gradually reduces the charging current it demands as the battery attains
full charge.
The absorption stage has the following exit criteria:
• Overall time in absorption timeout (
∆T
A
) has a default of 6 hours.
• Time in constant voltage absorption timeout
(∆T
CV
) has a default of 1
hour.
• Charge current level drops below a specified limit (I
H
) for a specified
amount of time, which has a default of 2% of C in Ah for 3 minutes.
See “Charge Algorithm Definitions” on page B–5 for more information.
With an AC reconnect during the absorption stage, the unit will transition
to the float stage for three-stage charging and no-float stage for two-stage
charging.