I've read that the float voltage for lead-acid batteries needs to be adjusted based on the ambient temperature that the batteries are charged in; that lower temperatures merit slightly higher voltages, and higher temperatures merit lower voltages on the battery for float charging.
I have had trouble finding a reference that breaks this out based on the ambient temperature, in a chart or table for example.
I live in the Phoenix, Arizona region, where the temperatures in the summer are easily above 115-120°F.
I have a 12V, 50Ah sealed lead-acid battery in the back of my vehicle, that is currently being used to power some accessories that are in the back of the vehicle, separate from the car's battery and electrical setup.
This battery is charged from a flexible solar panel that's mounted to the top of the vehicle.
The charge controller for this allows me to specify a float voltage, and the default value is 13.7V.
I'm sure, since it's frequently 120°F+ outside, and likely 130-140°F inside the vehicle while it sits in the sun, I need to adjust the floating voltage for this, but I don't know what level would be appropriate for this environment.
To summarize, What would be an appropriate float voltage for a sealed lead-acid 12V battery, in ambient temperatures of 120-140°F?
Update: Asked a separate question regarding the cut-off voltage when discharging and whether similar compensation is needed / how it should be calculated here