What prep can I do if I'm leaving FLA batteries unattended for 6 months?

[ron_jeremy]

Current system is made up of:

• 12 x 2V 960AH FLA batteries
• 3 x 350W panels connected to a Xantrex 150V/60A charge controller
• 3 x 350W panels connected to a Victron 150V/60A charge controller
• Trace SW4024 24V inverter

I have plans to be out of the country for 6 months but am concerned about leaving the battery bank unattended. Is there any prep I should do while I'm gone?

Should I just fill the batteries to the very top (that is, overfill them) the day I leave?
Or maybe just disconnect the solar panels from the charge controllers (via my solar isolator) and simply leave the batteries to self-discharge?
Or leave the charge controllers connected but set the bulk & absorption settings to be the same as the float voltage (or some other voltage?)?

There will be no loads while I'm away and the inverter will be off, too.

[Calsun]

I would rely on the two charge controllers not to overcharge the batteries. I would not leave them to self-discharge.

[ron_jeremy]

Looking at the charging specs for my batteries, would setting all 3 charge states to 24.0V makes sense?

davisdson-battery-charging-table.jpeg

[littleharbor2]

I'v done this when taking care of my neighbor's batteries.
First be sure the electrolyte is topped off. Turn off one of the controllers. shut down all loads, including the inverter. Set the bulk/absorb voltage to float voltage levels which should be 27.2 volts, not 28.2. The batteries will stay charged without any aggressive charging. This saves on electrolyte dissipation.

At 24 volts you have a nearly, totally depleted battery. If left at that level for 6 months you would do severe damage to your batteries

[ron_jeremy]

Iet the bulk/absorb voltage to float voltage levels which should be 27.2 volts, not 28.2.

Why 27.2 volts if the manufacturer recommends 28.2 volts for float charging?

[Bala]

Why 27.2 volts if the manufacturer recommends 28.2 volts for float charging?

There are enerally settings for cycling use or standby use.

28.2v for daily use. Batteries will charge more quickly but may gas so require topping up often.

27.2v for standby. If in good condition they will maintain charge withut gassing so not require topping up often.