Over-charge?

[MasseyRed]

Very novice here, so please bear with me...

New solar array - 350 watts of panels at 12 volts connected to a hub > renogy wanderer charge controller > 100ah lifepo4 battery > 4000 watter pure sine inverter.

My issue is when the panels and controller are connected to the battery and the inverter is on, things will run for a few minutes and the inverter reads 13.9 dcv (give or take .1) but the creeps up to 40...40.1 - then charge controller beeps, pv light goes solid, battery light flashes quickly, power cuts out, then seconds later it resumes.

The controller will go from solid pv light and solid battery light to slow flashing pv and solid batt, then the beep, quick flash batt light, cut out, resume with solid pv and solid batt (always green). Any idea what is going on? Is the charge controller not actually controlling the charge? I'm trying to learn and not instinctually good with this stuff so any assistance would be great.

 

[400bird]

Got any pictures of the set up?
Is the charge controller getting to 40 volts?! On your 12v battery? That's not good!

 

[Rednecktek]

but the creeps up to 40...40.1 - then charge controller beeps

???

The Wanderer is PWM, do you have 35 100w panels in parallel??

You're going to need a 40a MPPT controller and some restringing to feed that battery.

 

[MasseyRed]

Got any pictures of the set up?
Is the charge controller getting to 40 volts?! On your 12v battery? That's not good!

Sorry! Should say 14 and 14.1, not 40. Yikes

 

[MasseyRed]

There are 2x 100 watt and 2x 75 watt at 12 v each connected to a hub in par for 350 watts at 12v. The hub connects to the charge ctrl, and charge ctrl to the battery posts with a 30 amp fuse between the ctrl and the battery. The inverter is connected the the battery posts as well and a separate ground wire from the inverter to a steel rod in the ground. When the pannels/charge controller are connected to the battery and the inverter is on with a load (30 watt fan for example), the dc voltage in reads ± 14v, ac voltage out is 120v, and draw reads 30 watts. The dc volts in creeps up to 14.1, system shuts off for a second, drops to about 13.8v, comes back on, creeps up to 14.1 and repeats. Is it that there is something wrong with the charge controller? Things work fine when the solar/charge ctrl are disconnected.

 

[MasseyRed]

 

[MasseyRed]

Not the best pictures, but the best I have on my phone. The ctrl is not connected in these pictures, but would have wires and ring terminals on posts of battery when connected.

 

[Rednecktek]

14.1 is still low charging voltage for a LFP battery. Is the battery setting for LFP or lead acid? If it's still set for lead acid then it's going to freak out on over voltage on the battery.

Check your battery settings and make sure it's set for LFP or USR with the correct voltage settings.

You're probably nerfing your panels by putting those 75w panels in parallel with the 100w as all the panels will perform at the lowest amperage of the panels. I'm guessing the Vmp on all those panels is about the same so if you go to a MPPT controller put a 100w and a 75w in series, then parallel those sets.

 

[MasseyRed]

When you say battery setting, do you mean on the charge controller? It is set to Li. That said, I still don't understand what is causing the system to think it is overcharging.

 

[Rednecktek]

Try going to USR, setting the correct voltages, then back to Li. I had to do that on a couple of my controllers that had a similar issue.

 

[MisterSandals]

and charge ctrl to the battery posts with a 30 amp fuse between the ctrl and the battery.

Are these the black and white wires that are not connected to the battery?
I am sure that your manual says to connect the SCC to the battery before connecting to solar input.
This lets the SCC boot up for the correct battery voltage. If it gets hit with 22V from solar first, it may suspect you are trying to charge a 24V battery (i dunno but it would not be outrageous to design it this way).

 

[MasseyRed]

Are these the black and white wires that are not connected to the battery?
I am sure that your manual says to connect the SCC to the battery before connecting to solar input.
This lets the SCC boot up for the correct battery voltage. If it gets hit with 22V from solar first, it may suspect you are trying to charge a 24V battery (i dunno but it would not be outrageous to design it this way).

In the photo the solar is disconnected from the charge ctrl and the charge ctrl is disconn from the battery. Those pics are from after it started acting up. I had the scc connected to batt before pannels at setup.

 

[MasseyRed]

Try going to USR, setting the correct voltages, then back to Li. I had to do that on a couple of my controllers that had a similar issue.

Scc doesnt offer those options. No option to select voltage, just battery type (sla, gel, flooded, Li)

 

[Rednecktek]

Bummer... even cheap PWM 's nowadays even have a USR setting...

I'd lay money it's bad programming and it's still using the SLD voltages. Try the AGM setting, see if the higher voltages kick in.

 

[Gason]

Is the battery discharging normally? It is possible that the overvoltage protection of the BMS was triggered during charging.

 

[Texas-Mark]

That said, I still don't understand what is causing the system to think it is overcharging.

My guess is the battery has unbalanced cells and one goes into OV early and the BMS cuts off. at a lower total battery voltage The charge controller's output now jumps up because there is no battery connected and goes into OV too. Use the USER setting and lower the charge voltage.

You're probably nerfing your panels by putting those 75w panels in parallel with the 100w as all the panels will perform at the lowest amperage of the panels.

Aren't you thinking of when in series, not parallel?

 

[Rednecktek]

Aren't you thinking of when in series, not parallel?

I really need to get some sleep before I open my fat keyboard.