Question 6 volt Batteries in Class A

[Toolguy]

I am still adjusting to my Class A with all the new technology to me. 2024 Entegra Vision XL 31U.
I have 2 6 volt batteries hooked in series. Our last trip out we cut short because i was concerned i had a problem. Plus hooked up to 50 amp shore power.
The voltage on batteries dropped to 11.6 volts in the evening.
Lights did not dim, slides still worked. But I was nervous eventually I would not be able to retract slides.
I do have solar to help charge batteries.
It was in the 90’s with a high heat index. Both AC,s running heavy. Residential fridge. Fan running in living quarters. TV on as well as a few lights.
Batteries did recharge on the way home to 12.9 volts.

Have been communicating with Jayco via email. Their last response to me is this is a normal dip in voltage with everything running. Because it recharged to 12.9.

Several Question
1. Is this normal?
2. What would the bottom voltage drop be for slides to stop working. Or will they always work as long as it is hooked to shore power?
3. What should my Auto Generator start voltage be set at?
4. Does the AC, TV, and stuff running drain the 12 volt system?

This is our First Class A. Never had 6 volt batteries before. Never had a RV that would operate a lot off the inverter when not hooked up to shore power.

I just bought a battery tester but have not had a chance to go to storage to check batteries.

Thanks Dan

 

[Joe Hogan]

With a Large draw you might not have the battery capacity required. Two 6V is only enough for basic lights and standby for other items. Being on shore power should cover you for most items.

Lead Acid Battery Voltage Drop

Voltage drop in a lead-acid battery under load is a normal phenomenon and occurs due to the internal resistance of the battery. When a load is applied, the voltage initially drops, typically from around 13 volts to about 12 volts within the first minute of the load being applied This initial drop is more pronounced compared to the slower drop that occurs as the battery continues to discharge. The voltage drop is influenced by factors such as the internal resistance of the cell, the formation of sulfate, and the dilution of the electrolyte

Under load, the voltage of a lead-acid battery can drop significantly, but it is important to note that this voltage drop does not directly correlate with the state of charge. The state of charge is better determined by measuring the resting voltage, which is the voltage when the battery is not under any load and has been allowed to sit for a while For example, a voltage of 11.8 volts under load might indicate a lower state of charge, but this should be confirmed with a resting voltage measurement.

The voltage drop under load can also be affected by the size of the load. Higher loads can cause a more significant voltage drop, and if the voltage drops below certain thresholds, it may indicate that the battery is being discharged too deeply, which can be harmful to its longevity It is generally recommended to avoid discharging a lead-acid battery below 12.1 volts under load to prevent damage Additionally, the voltage should recover once the load is removed, indicating that the battery is in good condition

 

[MemoriesByTheMile]

Also check the settings on your inverter/charger. Be sure you know when the charger will kick in and charge the house batteries.
Driving back after your camping stay, depending on your configuration, your alternator may have been recharging the house batteries. This is why I would check to be sure your house batteries are charging while on shore power.