19 replies to this topic

[Jon R]

Well huh. Strange things are amiss. Put the charger on ....said it was charging ... a couple hours later I checked and the charger said done/full. Victron app solar said 14V ...Victron shunt said 14V but SOC was blank. I popped up and checked the lights, fridge turned on and was running fine. Then I tried the exhaust fan and it did not turn on. (it has been running fine all last year... a few years ago I had installed the variable speed circuit board which is/was great.... I bought 2 so have a spare).

So both batteries are fine apparently but the shunt still has no SOC reading at the top. Any thoughts on this conundrum?

Did you go into the app for the shunt and hit the SYNCHRONIZE button?

[Jon R]

Remember the shunt and the hardware/app don’t actually sense the state of charge. They just measure the net current in and out of the battery and integrate it over time to give you a state of charge relative to an arbitrary starting point. The SYNCHRONIZE button sets the state of charge reading to 100 percent as that starting point when you press it, and the integrator tracks it from there. You can set the integrator to reset to 100 percent automatically when charging voltage and current reach specific levels, or you can just manually hit synchronize every once in a while, like at the beginning of each trip if you know your batteries are fully charged. I have mine automatically synchronizing.

Regarding your fan not working …
Some posters here have reported that their Maxxaire fan control board did not work after being subjected to the higher charging voltage of lithium systems. I have not had a problem, but I have my max charging voltage limited to 14.2 vdc. Some people have theirs set as high as 14.6 vdc. It’s possible this caused your fan failure. I’d start by checking the fuse, though, and making sure the fan is free to turn.

Edited by Jon R, 15 April 2024 - 10:34 PM.

[buckland]

Thanks for your ideas. I just went out again and checked and in the Shunt app in the gear settings there is a "reset state of charge"  button.... should I first reset this before synchronizing?

[Jon R]

I assumed the app for the shunt looks the same as the app for my BMV-712. Here’s what my battery settings screen looks like. I don’t have a “reset state of charge” line item.  F1D14D6D-C375-4BC8-8025-6D5C3DE8F8FA.png   544.08K   3 downloads

Can you post a screen shot of your battery settings screen?

Edited by Jon R, 16 April 2024 - 02:05 AM.

[Bigfoot Dave]

Which side of the shunt was the charger attached to?

Bigfoot Dave

[buckland]

I will get out there this morning and try the suggestions and take a screen shot. I too have the charge set to 14.2 and the fan has been running for years on lithium. I'll check if it is stuck or the fuse too. Thanks again. It is really the first time I have had any trouble with the system .... And this happened just while the camper was on the truck but not being camped in (New England winters). 

Thanks again for your insights.

[buckland]

Below is the reset I mentioned. It will 'go into effect' after synchronization which I have not done yet. I thought I'd wait as it is a very sunny day..... so later this evening I will sync.  

Attached Files

•  IMG_3049.jpg   76.79K   5 downloads

[buckland]

Update!!! Gremlins be gone! They say you don't know what you have until It's gone... nope.... I am eternality grateful for folks here on WTW. I have a place to ask questions and get help.... where else would I go!!??

 

Got out there and pulled the fuses ...as the list on cover did not mention fan I pecked around. Think there was oxidation on one or two as now the fan works fine!!   I decided to synchronize at 13.7V as I was wanting to see if the SOC number came back and lo and behold there she am! So all is now well in River City! 

 

Appreciate help from you all. Now I can worry about something else!

Happy Spring

Rob

Attached Files

•  IMG_3050.jpg   112.19K   2 downloads

Edited by buckland, 16 April 2024 - 02:21 PM.

[Vic Harder]

I'd keep it as it is....  that way it should reset itself when it gets to 100%.

 

FWIW, I have run my BB's down to flat twice too, also because the SOC reading was way off.  In at least one case, it was because I had attached something to the wrong side of the shunt, which might be what Bigfoot Dave is asking about above.  

 

However, you haven't changed any wiring recently, have you?

 

Edit: OK, just saw your update, and the problem you reported is gone.   I'm not sure what you found?  Stuck contacts?  Fan running continuously?  Synchronization had NOT been done in a long time....   please clarify.

 

Also, when your batteries were dead and SOC read 100%, did you happen to notice the voltage reading?  Mine read 5.xV when "dead" or sleeping. 

[buckland]

Batteries weren't down they were full. No wiring change as I haven't used camper in 6 months. Fan didn't turn on. Now it does as I think fuse had oxidation. So batteries were never dead and fan works. All A-Okay now!! Appreciate the help.