Did I trash my batteries?

[MojaveJoe]

I hope I didn't over-discharge my batteries or do any major damage to them today

Was testing my new 1500W inverter system running 2 TVs and an in-motion satellite system...all day today.

After about 8 hours my low voltage alarm went off on my Xantrex inverter. It was still running and putting out 117V to my system. So I turned it off and tested the battery voltage....10.8V.
Five mintues later the batteries read 11.8V without a charge hooked up.

I immediately plugged in the RV to charge my 2
Interstate Deep Cycle Marine/RV SRM24 550CCA 698MCA batteries.

Looking at the voltage chart, it appears I discharged my batteries to or below 20%. My Xantrex low voltage alarm allegedly goes off at 11.0V or less.

I could really use some advice on how much damage I did to the batteries discharging so low, and if they are still serviceable. Getting ready to hit the hwy in a few weeks and I will replace them if necessary, even though they are only 2 years old.

All words of wisdom and experiences on such matters greatly appreciated.

Thanx,
Joe

[MojaveJoe]

I hope I didn't over-discharge my batteries or do any major damage to them today

Was testing my new 1500W inverter system running 2 TVs and an in-motion satellite system...all day today.

After about 8 hours my low voltage alarm went off on my Xantrex inverter. It was still running and putting out 117V to my system. So I turned it off and tested the battery voltage....10.8V.
Five mintues later the batteries read 11.8V without a charge hooked up.

I immediately plugged in the RV to charge my 2
Interstate Deep Cycle Marine/RV SRM24 550CCA 698MCA batteries.

Looking at the voltage chart, it appears I discharged my batteries to or below 20%. My Xantrex low voltage alarm allegedly goes off at 11.0V or less.

I could really use some advice on how much damage I did to the batteries discharging so low, and if they are still serviceable. Getting ready to hit the hwy in a few weeks and I will replace them if necessary, even though they are only 2 years old.

All words of wisdom and experiences on such matters greatly appreciated.

Thanx,
Joe

[FatDog]

what gave the voltage reading that said 20% (or less)? was it the display on the Xantrex or were you using a meter?
the Xantrex reader sounds a bit suspect if it didn't shut off at low voltage.
Mike

[MojaveJoe]

I used a hand held digital meter testing a direct tap off the battery bank. The Xantrex is supposed to shut down at 10.5V and alarm at 11.0V . I turned it off before it got to 10.5V

The 20% is my interpretation of a standard voltage/charge table.

The meter on board the fiver read generally "fair" state of charge at that time.

Is there anything special I need to do to properly recharge such drained batteries? Iam using the onboard charging system now.

Thanx.

[Ken Lenger]

Your batteries are probably OK. Recharge them and see what happens. Remember, people run vehicle batteries dead all the time by leaving headlights on and they still work for years.

[RV Wizard]

You can fully recharge the batteries and get rid of the surface charge and check each cell with a hydrometer. Each cell should have the same specific gravity, if one cell is very much lower than the rest, you could have a bad or weak cell and performance will suffer.