FWC Electrical basics and upgrading to lithium!

I suspect it’s a non-issue.

I have a 2021 Grandby with a Maxxaire fan with remote. My camper has seen several days of operation with the solar system putting out 14.6 volts for several hours (due to battery already at or near full charge) with the fan on and off. I subsequently dialed the charging voltage down to 14.2. It’s also briefly seen 14.8 volts a couple of times from the Iota shore power charger before I realized how high that device would push the voltage trying to force 30 amps into an already charged lithium battery when it first comes on in bulk charge mode. The 14.8 exposures were with the fan off. (I now use the Iota only as a 13.4 volt shore power converter and not regularly as a charger. )

My fan and remote control have been unaffected by this so far.
 
Seems to be a lot of people having issues for it to be a non-issue. Idk
 
craig333 said:
I've never had an issue at 14.6v nor have I heard of anyone who has.
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https://www.google.com/search?q=maxxair+maxxfan+voltage+regulator

I hope its not a problem, either way I'm installing a voltage regulator on the fan circuits. In that google search you can find threads from a lot of people who have had problems. I spoke with Maxxair and they seem very familiar with the problem and said 14v was the upper limit before the fan went into shutdown mode. Don't really understand why anyone would make a RV fan thats only rated for 14v??

On a side note, I contacted Dometic about my furnace, they said it was good up to 16v.
 
tstumpfig said:
General question on lithium batteries, my camper lives on the truck full time, do i need to be concerned about cold snaps where temps are below freezing for a few days to a week straight? I know that charging is a definite NO, but short term storage OK?
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I just returned from a ski trip with temps near zero or below....as a new and very happy convert to BB Li and all Victron devices [Bluetooth] here is my experience....with two Zamp solid panels and 340W of solar [170/160], I67 12-30, MPPT, DC/DC and 712 to maintain my heated 100Ah BB. With use of frig and furnace, no DC/DC, only partial solar, my SOC min was 89% and when returning to Hawk around 1400 hrs with cloud cover, 100% SOC..If I moved, at 30 amps the DC/DC always topped off the charge at 100% in a few minutes of driving...sweet system...

Note; Heated BB Li does not allow the battery temp to drop below 32 degrees F and in fact keeps it between 34-45 degrees to assure that solar charging happens while I was skiing...otherwise the BB BMS would stop charging below 32 degrees to protect the battery...you can get amps from battery below zero but can not charge it under 32...like previously stated you lessen the life of a Li battery by charging below 32...but can use all the amps from the battery even in extreme cold...
 
jdavis said:
I have the PD 30amp Converter/Charger for my Lithium upgrade. When running on shore power and charging the converter would provide 14.6v to my DC panel. This would run my furnace, fans, lights etc. Should I be concerned about my furnace and fans getting voltage that high? Should I consider a voltage regulator - something like this: https://www.amazon.com/gp/product/B08KZRZNCQ/ref=ask_ql_qh_dp_hza?th=1
Thanks
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Wanted to follow up on this. After a few weeks of use I have noticed the PD 30 amp only puts out > 14 volts at the very end of a charge. Then as soon as the battery is charged it drops back down to 13.8. So the window when the voltage is over 14 is pretty small. I have not had the main power switch on when my camper is charging so no idea how > 14 volts would affect the fans.
 
jdavis said:
https://www.google.com/search?q=maxxair+maxxfan+voltage+regulator

I hope its not a problem, either way I'm installing a voltage regulator on the fan circuits. In that google search you can find threads from a lot of people who have had problems. I spoke with Maxxair and they seem very familiar with the problem and said 14v was the upper limit before the fan went into shutdown mode. Don't really understand why anyone would make a RV fan thats only rated for 14v??

On a side note, I contacted Dometic about my furnace, they said it was good up to 16v.
Click to expand...
I have my Victron chargers limited to 14.2 Volts now. Today my solar was in float at 14.2 volts with the battery fully charged. the BMV712, my battery’s display, and my multimeter all indicated between 14.18 and 14.20 volts. I turned on the Maxxair fan to see if it would have any issues and it ran fine for several minutes before I turned it off.
 
KP - excellent write up and timely for me as I am considering the lithium upgrade from the OEM 2x 12v AGM ( 2020 Hawk with my own 340w solar and Victron MPPT 30 installed). The dc/dc is already installed. I understand that the IOTA - 30 IQ4 I currently have is not a perfect match for lithium. If I were to use something like the Victron Blue Smart IP22 charger, should I remove the IOTA entirely?
 
Gumbus said:
KP - excellent write up and timely for me as I am considering the lithium upgrade from the OEM 2x 12v AGM ( 2020 Hawk with my own 340w solar and Victron MPPT 30 installed). The dc/dc is already installed. I understand that the IOTA - 30 IQ4 I currently have is not a perfect match for lithium. If I were to use something like the Victron Blue Smart IP22 charger, should I remove the IOTA entirely?
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I’ve wondered about the same thing re my Iota. I emailed back and forth with their support folks and they could not answer with any confidence that the charger would take care of LifePo4.

I just replaced the stock ACR with a Victron 30A DC2DC. I have one 210w roof panel feeding a Victron MPPT . 206ah SOK is next on the menu .
 
Hey Carlos, I called SOK tech yesterday and they were of the opinion that our IOTA was not compatible for many varied reasons including improper cell balancing. As I do more research seems if I remove the IOTA I will lose the AC to DC connection to the rest of the electrical system while on shore power as the IOTA serves as a DC load device. Not a very big deal except for those occasions I want to pre-cool the Isotherm Fridge before a trip and don't want or can't use the battery (say a very cloudy day or the camper is stored in the garage before loading. Though I suppose I could just plug the Fridge into an extension cord directly on that rare occasion. This brings up another question, (I am entering the rabbit hole) my Isotherm 85L has a 120v plug to an outlet in the cabinet next to the unit. Does this mean it will charge via 120v if the IOTA is removed? Also Can the Isotherm 85L do the 120v vs 12V switching automatically?
I rarely us novice and electricity in the same sentence.
 
@gumbus the Iota is not ideal for these planned upgrades. I wonder what 4WheelCampers does when they sell the upgraded LifePO4 package? Funny thing the older Iotas needed a different module for charging AGM,LifePo4 and FLA. I think if you had the older one, with the right add on it would work.

I’d also not mind eliminating the Iota, but to your point there would be some loss of functionality.

I think the fridge automatically switches it’s power intake , but I would want to know for sure from the manufacturer.
 
I can't remember what FWC video I watch on this matter but a reference was made that the LiFe upgrade eliminated the IOTA but they did not mention what charger they substituted.

Carlos - just a thought, the direction I am going is 1x SOK 100ah battery which is 10.6" L / 7.9" W / 9.1" H . I have 340W solar on top, see how it goes for a while and if needed I can add another SOK 100ah. The cabinet is 22" wide so in theory I should be able to make the addition without any dimensional modification to the cabinet and save myself $600.
 
Gumbus said:
Also Can the Isotherm 85L do the 120v vs 12V switching automatically?
I rarely us novice and electricity in the same sentence.
Click to expand...
I have the Isotherm 130L 2 way fridge in my 2021 Grandby. If 120vac is connected to the camper and both the main and fridge 120vac breakers are on, the fridge will run from the 120vac regardless of the availability of 12 volt power. If it is operating on 12vdc at the time 120vac becomes available, it will automatically switch over to 120vac. I just verified all this by test.

You can leave the 120vac breaker for the converter turned off if you don’t want the Iota to operate while the 120Vac is connected. You can also turn that breaker on but turn off the silver battery switch and the Iota will then function as a 12 vdc power supply without charging or discharging the camper battery.
 
BerkeleyCarlos said:
@gumbus the Iota is not ideal for these planned upgrades. I wonder what 4WheelCampers does when they sell the upgraded LifePO4 package? Funny thing the older Iotas needed a different module for charging AGM,LifePo4 and FLA. I think if you had the older one, with the right add on it would work.

I’d also not mind eliminating the Iota, but to your point there would be some loss of functionality.

I think the fridge automatically switches it’s power intake , but I would want to know for sure from the manufacturer.
Click to expand...
Correct, with the older Iota chargers they had provision for a dongle to be switched out depending on the battery chemistry
 
Gumbus said:
I can't remember what FWC video I watch on this matter but a reference was made that the LiFe upgrade eliminated the IOTA but they did not mention what charger they substituted.
Click to expand...
I use Victron gear throughout, so Orion DCDC, 100V/30A MPPT and IP67 AC/DC chargers. No iota in my system at all. Mind you, I also have no shore power that goes to any AC outlets. My AC port on the outside of the camper goes direct to the IP67 ACDC charger and I run everything off of DC. Makes sense for me as we almost never plug in while camping.
 
Gumbus, I would be better off with the 100ah SOK since I am still running the stock 92ah boat anchor of an AGM. But….the 206ah is calling my name. I am 99% sure it will fit.
 
I was thinking about that . The only voltage I see listed is 14.6, nothing else . Don’t LifePo4’s want 13.8 at some point ?
 
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