Am I killing my batteries?

[Bowedtoothdoc]

I have an AC driven cold plate system for my fridge and freezer. Normally they won"t even run off of my inverter. After anchoring overnight they are in badly in need of recharging and they will kick on without overloading the inverter. This morning to avoid waking up my two boys I turned them on and they were drawing around 115 amps for around 45 min and my batteries were showing 11.5 Volts. Once done charging the battery meter was back at
12 Volts. I might add that my house bank is 6 6 volt batteries and around 700 amp hours. Is this damaging my house bank?

 

[Bowedtoothdoc]

Also after turning off inverter voltage jumps to 12.2 Volts

 

[Don S/V ILLusion]

The short version answer is no - although your batteries will be happier and last longer if you don't routinely draw them down below 50% capacity.

 

[Stu Jackson]

What was the voltage before you turned it on?

Inverters draw, as you know, some pretty large loads. This usually decreases the system voltage, but it recovers when the heavy inverter load is turned off.

Do you have a battery monitor? What is the state of charge of your house bank?

 

[Bowedtoothdoc]

What was the voltage before you turned it on?

Inverters draw, as you know, some pretty large loads. This usually decreases the system voltage, but it recovers when the heavy inverter load is turned off.

Do you have a battery monitor? What is the state of charge of your house bank?

Yes, I have a Magnum Charger/Inverter 2800 watt with the Magnum Battery Monitor. Showing 12.3 Volts now that the inverter is off.

 

[mitiempo]

12.3 is about 60 - 65% state of charge. I hope you are charging fully often.

 

[Benny17441]

For voltage to adequately reflect the state of charge the battery must be at rest for a couple of hours. If a voltage reading is taken on a battery that just a few minutes before had been subjected to a load the voltage reading will be lower than the actual and will reflect a lower state of charge.