I would agree with Mojoman about batteries and locations. We just got back from a hot, but not like his, trip. Our 4 AGMs are located in the old generator space behind the rear axle, like many of the new ones do now.
We consistently see about 15-20*F above ambient at the battery temp sensors, which appear to be maybe 5* warmer than the battery internals.
On a 95* day, that makes for hot batteries, beyond recommended temps.
We did run into an interesting observation, though, when the batteries got near 110*. All the charging sources reduced the charge voltage a bunch, so when we were in float, the voltage charging was lower than the battery voltage which had been charged at a lower temp. I don't know if they odd situation would help, hurt, or do nothing for battery damage and life, but I would think that going to basic no charge, give up some energy might actually be a good thing.
I think I will revisit getting some more cooling air to the batteries, though.