User Manual

VRLA AGM
BATTERIES
ROLLS VRLA AGM BATTERY
CHARGING INSTRUCTIONS
To maximize the life of your Rolls VRLA AGM battery, it is important that it is properly
charged. Over or undercharging a VRLA AGM battery will result in shortened cycle life.
The best protection from improper charging is to use a quality charger and routinely
checking that the charge current and manufacturer-recommended voltage settings
are properly maintained.
VRLA AGM CHARGING GUIDELINES
To maintain good health, VRLA AGM batteries should be brought to a full charge
on each cycle or, at minimum, once every 6-7 days. Charge should be completed
in a ventilated area as hydrogen gas may still be released through the pressure
relief valve if the batteries are excessively overcharged. Never charge a frozen
battery. Ideal charging temperatures: 0°C-40°C (32°F-104°F).
VRLA AGM CHARGING CHARACTERISTICS
To maximize your battery life, a voltage regulated charger with temperature
compensation is strongly recommended. Refer to Table 5 VRLA AGM Charge Voltage
for the recommended charging parameters. Charge voltage should be set to 2.45vpc
@ 25°C (77°F) to allow the charger to properly adjust voltage with temperature
compensation. Temperature compensation should be programmed as specified in
Table 5 with adjustment in increments of 4mv/ºC/Cell. Without temperature compensation,
voltage settings should be manually adjusted for temperatures varying from 25°C (77°F).
As temperature decreases, the voltage should increase and vice versa. If the charger
has a preset charge profile for VRLA AGM type batteries, verify that these voltage
settings follow the battery manufacturer's specific charging parameters.
VRLA AGM BULK & ABSORPTION CHARGE
VRLA AGM batteries have a lower internal resistance than Flooded models, allowing
them to accept current more efficiently. It is recommended that the initial charge current
is set at 20% of C/20 of the battery bank (min 10% / max 30% of C/20) in order to fully
charge the batteries within a reasonable amount of time. It may be set lower, however,
this will increase the required charge time. It is very important that VRLA AGM batteries
are brought to a full charge frequently to prevent capacity loss. It should also be noted
that, unlike Flooded models, these batteries should NOT be equalized to recover capacity
loss. This program setting should be disabled in the charge controller to prevent
accidental overcharge.
The charger should deliver the initial max current at the programmed Bulk voltage
until the voltage limit is reached, then switching to the Absorption charge phase.
The charger should maintain the Absorption voltage until current tapers to the
programmed End Amps value (3-4% for VRLA AGM models).
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