Petar Maksimovic avatar image
Petar Maksimovic asked

Battery safe on MultiPlus with Super AGM batteries

I have set up a pair of 12/3000/120 paralleled Multi's for use with 6x125Ah Super AGM's.

Settings chosen for charger is AGM Victron deep discharge, fastest recharge, as the genset is run on board in the mornings to top up overnight consumption. Now Multi goes often into Battery safe mode. Shall the charge curve be changed to Adaptive only, or battery safe is appropriate option for Super AGM's?

MultiPlus Quattro Inverter Chargerbattery chargingAGM Battery
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1 Answer
Johannes Boonstra (Victron Energy Staff) avatar image
Johannes Boonstra (Victron Energy Staff) answered ·

Hi, In a lead acid battery the charge proces isnt always perfectly spread throughout the battery so therefore it can happen that when charging fast ( at the limit of what the battery can handle voltage wise), a part of the battery is already "charged"while other parts still have the ability to absorb energy. When the charger is going "full 'power to the setpoint voltage to enter absorption the change is quite realistic that a part of the battery is getting overcharged. Therefore the Battery Safe is developed. Battery Safe reduces the charge current when the voltage is approaching the setpoint to enter absorption. Therefore the battery gets a longer lifetime.

Same as for Adaptive (when the absorption period is calculated from the time the charger is in the Bulk phase) , it helps extend the lifespan of the battery.

In general, beware that the wish to charge "as fast as possible"often results in a shorter lifespan of the (lead/acid) battery. Taking it a bit slower will indeed cost fuel/time but will pay itself back in battery lifetime. Charging the battery with the generator is most efficient in the 50-80% SOC range. So have this done daily and only go to 100% weekly as then the battery monitor is synced and the battery gets a needed ful charge.

2 |3000

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