MaxFan voltage issues

[Jack!]

Reading many problems reported on the MaxxFan control boards frying by way of "over voltage" when using mppt solar controllers. Has MaxxFan addressed this issue?

Are any other 12v appliances at risk when voltages exceed the 13 volt range? Seems the 14 volt range is common and required with a Li battery system.

[Perry Butler]

Originally Posted by Jack!

Reading many problems reported on the MaxxFan control boards frying by way of "over voltage" when using mppt solar controllers. Has MaxxFan addressed this issue?

Are any other 12v appliances at risk when voltages exceed the 13 volt range? Seems the 14 volt range is common and required with a Li battery system.

When our 2018 Maxxfan board failed the company claimed the new board will be able to handle our SiO2 batteries 14.6 bulk/equalization charge and our 13.1 charge at 100% full. It was received and installed last August. We'll see how this board lasts.

We leave our fan on low the entire time we're camping.

Enjoy,

Perry

[tdf-texas]

Originally Posted by Jack!

Reading many problems reported on the MaxxFan control boards frying by way of "over voltage" when using mppt solar controllers. Has MaxxFan addressed this issue?

Are any other 12v appliances at risk when voltages exceed the 13 volt range? Seems the 14 volt range is common and required with a Li battery system.

The latest version of the Maxxfan control board seems to be holding up while operating at solar controller voltages so "maybe" that one device has been fixed.

Other devices in your RV in addition to the previous versions of Maxxfan that don't tolerate higher voltages are the Suburban SW6DE control board and the Atwood AFSAD12 / Dometic™ AFSD12 gas heater control board.

Both of these devices have manufacture stated high voltage limits of 13.7v. That voltage limit seems to be conservative though as once past infant mortality, the boards have a history of holding up while operating with higher voltages.

I have voltage regulators on all three devices as it seems to always happen that when a device is really needed, that is when it will fail. The install of the voltage regulators at least means that over voltage won't be the reason it fails.

ps. I always carry spare voltage regulators just in case that was the failure.

[Jack!]

Originally Posted by tdf-texas

....I have voltage regulators on all three devices as it seems to always happen that when a device is really needed, that is when it will fail. The install of the voltage regulators at least means that over voltage won't be the reason it fails.

Thanks for this info.
Dang! I was hoping that wasn't the case. Happened to see a post on the MaxxFan 14v issue and said to myself, "wait a minute...what about all the other dc stuff"?

So you are using voltage regulators for Furnace, MaxxFan, water heater if I have that right. Guess water heater igniter is at risk.
Everything else is good? Frig, water pump, bath fan, LEDs, 5.0 landing gear, radio, detectors, etc...
What regulators did you go with?

Does it make sense to wire voltage regulators coming off the DC board on each circuit at the power center source or doing regulators at each device location?

[Jack!]

Originally Posted by tdf-texas

The latest version of the Maxxfan control board seems to be holding up while operating at solar controller voltages so "maybe" that one device has been fixed.

Just spotted your detailed post on the ETI forum. Answered most of my questions.
Thanks much!

[RangerMan]

Originally Posted by Jack!

Does it make sense to wire voltage regulators coming off the DC board on each circuit at the power center source or doing regulators at each device location?

Does to me. Anyone do it this way? Altho most of the DC runs have multiple loads on then.

[elongest]

My question is, can a DC to DC charger be installed between the converter section and DC distribution panel and act as a voltage regulator for your entire house voltage?

[Rockhead]

To tdf do you have a link to the converters you used on you fan

[tdf-texas]

Originally Posted by Rockhead

To tdf do you have a link to the converters you used on you fan

https://www.escapeforum.org/forums/f...tor-14667.html

[tdf-texas]

Originally Posted by elongest

My question is, can a DC to DC charger be installed between the converter section and DC distribution panel and act as a voltage regulator for your entire house voltage?

The 12v regulator I use is a boost/buck type that outputs a constant 12v with an input voltage of 5-32 volts. It can handle a 14 amp load. That's big enough to handle any one of the three devices in the RV that need regulation. It costs about $22.

A DC to DC charger that could handle the entire RV would need to be able to handle about 50 amps and be able to use input voltages between 10 to 16 volts. The wide input voltage range is due to three voltage sources feeding it - the converter, the battery, and the solar controller.

A voltage regulator that would meet those specs would be expensive.
https://invertersrus.com/product/vic...0%7C%20%241260

[Jack!]

Originally Posted by tdf-texas

A voltage regulator that would meet those specs would be expensive.

Ouch! Yes, too expensive considering your voltage regulator solution. Looks like I need to add some extra control boards & these voltage regulators to my personal parts department for on the road problems. Will add the regulators once we get the new trailer this week. Want to see the actual devices ETI to installed & make sure on the model numbers.

I did post a question for ETI at their forum to learn what they know on using Li rated charger voltages. They likely get a lot of calls if this issue is ongoing.

[tdf-texas]

Originally Posted by Jack!

Ouch! Yes, too expensive considering your voltage regulator solution. Looks like I need to add some extra control boards & these voltage regulators to my personal parts department for on the road problems. Will add the regulators once we get the new trailer this week. Want to see the actual devices ETI to installed & make sure on the model numbers.

I did post a question for ETI at their forum to learn what they know on using Li rated charger voltages. They likely get a lot of calls if this issue is ongoing.

When considering purchase of spare control boards, you might want to consider these. Much better designed boards with better high voltage tolerance.
https://dinosaurelectronics.com/index.htm

[Perry Butler]

Our solar controllers are directly hooked to our batteries, and we do not use the WFCO to charge our batteries at a full hookup site. We haven't used the WFCO charger in a year since our solar has no problem keeping our SiO2 batteries fully charged. Why can't I install a voltage controller on the battery wire that goes from the battery to the WFCO to feed 12.8 volts to all our DC appliances?

Thanks,

Perry

[tdf-texas]

Originally Posted by Perryb67

Our solar controllers are directly hooked to our batteries, and we do not use the WFCO to charge our batteries at a full hookup site. We haven't used the WFCO charger in a year since our solar has no problem keeping our SiO2 batteries fully charged. Why can't I install a voltage controller on the battery wire that goes from the battery to the WFCO to feed 12.8 volts to all our DC appliances?

Thanks,

Perry

Sure! You can do that but the solar controller is still going to put out 14.4 or more volts connected to the battery. To keep the voltage to the RV at 12.8v, consider what amp draw you would need the voltage regulator to handle. That's a lot of amps. And that is what I was trying to convey with the previous post - one that size is expensive.
https://www.escapeforum.org/forums/f...tml#post410110

[Jack!]

Originally Posted by Jack!

Reading many problems reported on the MaxxFan control boards frying by way of "over voltage" when using mppt solar controllers. Has MaxxFan addressed this issue?

Recieved an ETI response regarding this matter. Seems things may have changed & problem has been improved now in terms of the MaxxFan. Water heater and furnace may remain an issue but perhaps those control boards have been updated as well. I may call & ask.
ETI doesn't use mppt solar controllers & didn't comment in that regard.

__________________________________________________
Darryl @ ETI
Yes, the MaxxFan circuit boards have been updated to handle voltage up to 15.5 volts. The converter outputs 14.6V to the lithium battery but the DC branch circuits which the appliances, lights etc. are all at the 13.6V when under load. This fits the specification for our DC systems.

[Perry Butler]

Originally Posted by tdf-texas

Sure! You can do that but the solar controller is still going to put out 14.4 or more volts connected to the battery. To keep the voltage to the RV at 12.8v, consider what amp draw you would need the voltage regulator to handle. That's a lot of amps. And that is what I was trying to convey with the previous post - one that size is expensive.
https://www.escapeforum.org/forums/f...tml#post410110

I have replaced the GP solar charge controller with two Victron solar controllers. The solar positives and negatives are directly connected to the battery, with breakers in between, so that shouldn't be a problem. The WFCO is connected to the battery with a separate line already. I would put the regulator between the battery and the WFCO.

When I get home this April I'll take an inventory of amps needed. I don't think it will be that much. LED lights, Maxxfan, water heater, refrigerator, furnace, etc. The furnace will be the largest draw. We never use the fridge on DC. We do charge our two phones and laptops at night using standard USB, so that would add three or so amps. I estimate a total of 10 amps needed at any one time.

Thanks,

Perry

[elongest]

Originally Posted by Jack!

Thanks for this info.


Does it make sense to wire voltage regulators coming off the DC board on each circuit at the power center source or doing regulators at each device location?

How about a Bud box with several regulators in it, one for each affected circuit? Everything in one location. If you wanted to get fancy you could use a multi pin connector on your box and have a jumper plug if you did not want to use the regulators.

[tdf-texas]

Originally Posted by Perryb67

I have replaced the GP solar charge controller with two Victron solar controllers. The solar positives and negatives are directly connected to the battery, with breakers in between, so that shouldn't be a problem. The WFCO is connected to the battery with a separate line already. I would put the regulator between the battery and the WFCO.

When I get home this April I'll take an inventory of amps needed. I don't think it will be that much. LED lights, Maxxfan, water heater, refrigerator, furnace, etc. The furnace will be the largest draw. We never use the fridge on DC. We do charge our two phones and laptops at night using standard USB, so that would add three or so amps. I estimate a total of 10 amps needed at any one time.

Thanks,

Perry

10 amps may be a little low. Think worse case scenario - the furnace is running, the range vent fan is running, bath fan is running, fridge is on, and you turn on the Maxxfan. See where I'm heading? You're going way over 10 amps with even several of these devices running.

[Perry Butler]

Originally Posted by tdf-texas

10 amps may be a little low. Think worse case scenario - the furnace is running, the range vent fan is running, bath fan is running, fridge is on, and you turn on the Maxxfan. See where I'm heading? You're going way over 10 amps with even several of these devices running.

I'm purchasing a Victron Orion Tr Smart 12/12-30a DC-DC charger. This unit can also be used as a regulated power supply with a 30 amp limit, so I should be good.

Thanks,

Perry

[Perry Butler]

Originally Posted by tdf-texas

10 amps may be a little low. Think worse case scenario - the furnace is running, the range vent fan is running, bath fan is running, fridge is on, and you turn on the Maxxfan. See where I'm heading? You're going way over 10 amps with even several of these devices running.

I'm purchasing a Victron Orion Tr Smart 12/12-30a DC-DC charger. This unit can also be used as a regulated power supply with a 30 amp limit, so I should be good.

For those who missed it, read my Boards Frying From 14 volt Solar Charging? thread for more detail.

Thanks,

Perry