To maximize the life of your Rolls AGM battery, it is important that it is properly charged. As with all

lead-acid batteries, both over- and under-charging a Rolls AGM battery will result in shortened service

life. The best protection from improper charging is the use of a quality charger and routinely

checking that the charger current and voltage settings are maintained.

 

Please read the following instructions before using your battery.

 

Charger Inspection

The charger cabling should be insulated and free of breaks or cuts. The cable connectors should be

clean and properly mate with the battery terminals to ensure a snug connection. The charger’s AC

cord should be free of breaks or cuts and the wall plug should be clean.

 

Charging Guidelines

  • Fully charge batteries after each use.
  • Charge in a ventilated area as gasses may be released through the pressure relief valve if the

          batteries are excessively over-charged.

  • Never charge a frozen battery.
  • Ideal charging temperatures: 32°F – 104°F (0°C – 40°C).

 

Charging Characteristics

If the charger has a setting for AGM, use this setting to charge your Rolls AGM battery. To maximize your

battery life a voltage regulated charger with temperature compensation is strongly recommended.

 

Voltage Regulated Charger - IUU

VRCIUU.jpg


The initial charge current is recommended to be set at I1= 0.25 X C20 (Imax= 0.35 X C20) in order to fully charge the batteries within a reasonable amount of time.  It can be set lower, however please be aware that charge time will increase so make sure the batteries have enough time to fully charge before being put back into service. Rolls AGM batteries have a low internal resistance allowing them to be charged at a higher current, therefore faster, than conventional flooded/wet batteries.

 

Bulk stage - the charger should deliver the initial current I1 until the voltage limit U0 is reached.


Absorption stage - the charger should maintain the voltage U0 until the current tapers to I2.


Float stage and termination – the charger can maintain the current I1 indefinitely or until the charger is shut off or unplugged.  This stage is ideal to maintain battery state of charge.

 

Make sure the temperature compensation is programmed as specified in the graph above (-4mV/°C/cell or -2mV/°F/cell) or manually adjust the voltage setting for temperatures varying from 25°C (77°F).  As the temperature decreases, the voltage should be increased and as the temperature increases the voltage should be decreased. The profile in this graph can be used with or without the float stage.  Without the float stage, recharge can be terminated based on time (this will need to be determined as it will vary with depth of discharge and charge current) or percentage recharge (~105%-110%).

 

Charge Voltage Quick Reference:


For a 6V battery divide the voltage by 2.

 

Constant Current Charger - IUIA constant current charger can also be used, however it is important to adhere to the termination criteria mentioned below to minimize the chance of excessive over-charge.  See figure below for the recommended constant current charge profile.

 

CCCIUI.jpg

 

Bulk stage - the charger should deliver the initial current I1 until the voltage limit U0 is reached.

Absorption stage - the charger should maintain the voltage U until the current tapers to I2.

Termination - If the charger can be programmed, the charge should terminate when the voltage stops

increasing over time. This is called a dV/dT termination. The charge should terminate when the dV/dT

is equal to 2.5mV/cell/hour.

 

The charge time in the final phase should not exceed 8 hours and the total charge time should not

exceed 20 hours.

 

The percentage recharge should be between 105%-110%.