Lithium batteries, Maxxair fan

[J&J___]

I am looking to add a Maxxair fan in the bedroom of my 2020 337RLS. While researching the fans I found some information that the Maxxair fans have a maximum input voltage of 13.9V DC. Since I have upgraded to lithium batteries, this is a problem because the lithium batteries run at 14.4+-. I talked to Maxxair support and yes their fan boards are designed to shut down at voltages above 13.9 to prevent damage to the board. Their recommndation is to put a DC to DC voltage regulator inline before the fan. My factory installed Maxxfan in the kitchen is working fine off the higher voltage but according to Maxxair the higher voltage could be a problem.

So this is an FYI to anyone with lithium batteries, if your Maxxair is not working properly you may need a voltage regulator.

Before putting in the lithium batteries in I did a lot of research to see if the higher voltage would cause any problems. I didn’t find any problems. Looks like I missed this one. Adding an inline regulator is a simple fix but something to know about.

Anybody found any other problems with the higher voltage of lithium batteries?

[BB&LAB]

We have a Maxxair fan and lithium batteries on our current 5er and a two previous rigs with no fan issues.

[J&J___]

We have a Maxxair fan and lithium batteries on our current 5er and a two previous rigs with no fan issues.

That is good to hear. I suspect it is an erratic problem but the service tech I talked to sounded like it was not an uncommon question, he was quick with the answer and solution and said they had redesigned their boards to shut down at higher voltages.

[JKellerJr]

We have a Maxxair fan and lithium batteries on our current 5er and a two previous rigs with no fan issues.

I concur, we have 2 maxxair fans and lithium batteries have had no issues.

[jkwilson]

I’d be stunned if they are limited to 13.9V. With any kind of batteries, they’ll see more than that when the converter is on. Most “12V” electronics are designed to operate at 13.8VDC, So 13.9V is barely off dead-center.

[DarthMuffin]

No problems with our maxxair either, even when plugged into shore power and the inverter is putting out the required 14.6V for charging lithiums. Maybe not run it at 100% speed if you're worried about the motor?