Battery Charge Question

Here is what I have. 2 100 watt MMPT panels
40 amp Renogy Rover Controller

Pooxtra 1000 pure sine wave inverter

200 ah Renogy sealed battery

Renogy Bluetooth module


Here is the issue. 

I went out last night to set things up in the tear drop. I hooked everything up minus the solar panels (so no charge). The battery was about 62%. I ran a few things for a bit (some lights and a very small heater). When things got down to 52% (reading on the controller and the Blue Tooth App)  I turned off the inverter and called it a night. 

Today I went out to check on the battery level and I was up to 76% on the battery  - this was a surprise to me. I thought I'd be at 52% or less. 

It did get cold last night but does that really cause a 24% gain? 

Thanks in advance! 

juggleslumpus, I think you find as others have that the SoC reading are bogus and likely should be ignored.
Reading battery voltage would be my suggestion and letting your grey matter become the SoC meter.

Let's go through one charge cycle. In the morning the batt under no load are @ 12.2v or ~50%, the sun shines and the controller is goona try to get your battery to 14.4 or 14.6 (depending on type of battery), at some point it gets to say 14.4 and stays there 2 hrs and then the controller tries to keep it at 13.?v float. During all this time you are using the battery and causing it to discharge, if ya use it more than ya charge it won't get fully charged (ain;t that the goal?). Dynamic as hell.

Of course during charge the batt v should be higher than during discharge and how does the poor controller know which is goin on?

batt monitors count what goes in and out of a battery and TRY to determine SoC based on that but these controllers are not that fancy.

We do not know the algorithm that your controller uses but letting it rest (no load) and the voltage likely rises and Soc would report a higher Soc at a higher voltage or so we assume!!!!

I hope the sun shines enough each day for your battery to get to the mid to upper 14v and stay there for a while, if it does it will last a long time.

small heat??? ya know that 500 watts is 500 watts (inverter ineff ingored). so 500 w / 120v = 4.2A and @ 12v it is over 42A, do that for a hr or two and your battery is severely discharged!

also remember that I have a bias towards inverters since their amp usage at 12v is TEN times+ their 120v usage and batts cost money so I insist that a motor/alternator be spinning if I use an inverter.

 
Yes sir and even that will change when you start using your solar for more than minimal usage......

But I'm really glad your finally coming around on the SOC.... I really wish they would take it completely out of the CC sense it means nothing but confusion...

Thanks for the quick replies - lot's to chew on here. One thing though - the solar panels were disconnected during this time (still are) so there was no charging going on. Is the controller display really that unreliable?

 On the SOC yes it's meaning less.... The rest works just fine...

Why do you have the panels disconnected?

I was just messing around with the inside of the trailer and hooking things up. The panels will be portable (not attached to the trailer). 

I believe what you guys are telling me - but I am surprised a Renogy Rep is not chiming in here. I do want to understand Solar power at a deeper level but I was hoping a gauge could as least help me keep an eye on the battery level. Keeping it in my "grey matter" doesn't strike me as a really good solution. 

It's like having a gas gauge on a car that hits the 1/2 tank mark but may really be empty! 

Get a digital volt meter and mount it on the wall... That is your gauge for battery level...

By the way I have been on here for over a year and I have never seen any Renogy people on here....