On our 2020 3931FB, the cooling fan most often catches my attention by cycling on frequently when we are using the indirect led accent lights. That's nearly 80 feet of led light strip so there may be a draw on the batteries sufficient to require the converter to charge more?
I suppose the bathroom fans draw a lot of 12v current too but I don't notice the converter fan because of their noise and then there is the noise from the air conditioners.
Our batteries have only been in service 5 months so I haven't checked them yet however i do realize that I should be checking them frequently but not a fan of the battery box design, those extra cable connections are a hassle.
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