Agm 100ah battery

[mike2scuba]

can anyone advise what figures i should enter into a shunt monitor with a 100ah agm leisure battery

 

[Solarcabin Channel]

Low voltage cut off for flooded and AGM to be safe is 11.6 volts.

High voltage or charge voltage is 14.6-14.8.

Full capacity or float charge is 13.6-13.8.

Since that is a "leisure" battery I would not push those limits to make it last longer.

 

[mike2scuba]

so set the high voltage at 14.6v
low volts to 11.6v
alarm at 50ah

 

[Solarcabin Channel]

so set the high voltage at 14.6v
low volts to 11.6v
alarm at 50ah

That should keep it safe!

 

[mikefitz]

what figures i should enter into a shunt monitor with a 100ah agm

CAP 100.00Ah for a new battery, reduce by 3 to10% per year for ageing
HIGH V charger absorption volts -0.1 volt, example if charger absorption volts = 14.4, set to 014.3V
LOW V minimum voltage of battery. with AGM its not advised to discharge to zero SOC , so although 010.5V is set you should never reach it
Alarm ideally do not charge much below 50% SOC, Set as desired, example 040.0Ah adjust for each year ageing

note the monitor uses the HIGH V or LOW V to sync to 100% or 0%. Since its unlikely you will discharge to 0% its the HIGH V that will sync. However AGM needs a long absorption, perhaps up to 4 hours depending on conditions , so the monitor may show 100% when the actual SOC is less, say 90%, when the battery is charging.

To initially set the battery monitor to 100% fully charge the battery and on the monitor,
hold key ^ for 3 seconds
Ignore the Renogy suggestion to fully discharge the battery.

Because the Renogy monitor does not have settings for charge efficiency ( that may be 90% for AGM) or Peukerts constant (modification to SOC under different discharge currents), the readings of SOG will not be totally accurate. The Renogy monitor is a useful product for battery housekeeping but regard as a guide not an absolute measure where SOC is concerned

The battery capacity will age with natural ageing and cycle use so modifying the CAP and Alarm may be needed after some time.

Mike