Help with solar controller error.

[chanzer]

Hello,
I bought a Renogy 40A MPPT solar controller. I have a lithium-ion battery at 12.6V. (currently charged at 11.2V)
I have entered the voltages:
Equalizing voltage=9V,
Boost voltage=12,6V
Floating charging voltage=9V,
Over-discharge voltage=11V,
Over-discharge return voltage=10.5V,

The error symbol keeps flashing. When I go to errors it says E3. Can you please tell me how to make it stop doing that... ? Thank you.

 

[MisterSandals]

Over-discharge voltage=11V,
Over-discharge return voltage=10.5V,

At first glance, these numbers seem wrong. If you have it set to stop discharging at 11v, why would you have it resume discharging when the battery is LOWER at 10.5v?

Try setting Over-discharge return voltage to 12v.

Maybe your SCC is doing a little sanity checking and this is the error?

 

[MisterSandals]

Floating charging voltage=9V,

And this seems wildly low too. For my SCC's, the float voltage is the level of discharge where the SCC resumes charging.
So after it charges to max voltage, it stops charging until it "floats"/coasts down to the float voltage.
I would set the float voltage to a level just below where your batteries settle after being charged. This will prevent micro-cycling where it charges, settles to float voltage and then recharges again. Over and over...

And these voltages all seem low for lithium-ion. Not LiFePO4?

 

[chanzer]

At first glance, these numbers seem wrong. If you have it set to stop discharging at 11v, why would you have it resume discharging when the battery is LOWER at 10.5v?

Try setting Over-discharge return voltage to 12v.

Maybe your SCC is doing a little sanity checking and this is the error?

Renogy wrote me this: An over-discharge return voltage is the voltage where the controller will charge it up to after the battery is over-discharged -> lower than just discharged. Lower than 11V

 

[chanzer]

And this seems wildly low too. For my SCC's, the float voltage is the level of discharge where the SCC resumes charging.
So after it charges to max voltage, it stops charging until it "floats"/coasts down to the float voltage.
I would set the float voltage to a level just below where your batteries settle after being charged. This will prevent micro-cycling where it charges, settles to float voltage and then recharges again. Over and over...

And these voltages all seem low for lithium-ion. Not LiFePO4?

I asked Renogy what to set since lithium-ion batteries should not be float charged or have equalized charging voltage and they told me to put the lowest possible which happens to be 9V. Thank you for the advice though. I will try that.

 

[MisterSandals]

I am not familiar with your SCC, and all the wording is just a little different.
I see low voltage reconnect recommended 12.6v here. Not seeing over-discharge return.

https://www.renogy.com/template/files/Manuals/RNG-CTRL-RVR2040_V1.5.pdf

 

[chanzer]

I am not familiar with your SCC, and all the wording is just a little different.
I see low voltage reconnect recommended 12.6v here. Not seeing over-discharge return.

https://www.renogy.com/template/files/Manuals/RNG-CTRL-RVR2040_V1.5.pdf

That is for Lifepo4 not lithium-ion. Big difference. Thank you for trying though.

 

[chanzer]

I asked Renogy what to set since lithium-ion batteries should not be float charged or have equalized charging voltage and they told me to put the lowest possible which happens to be 9V. Thank you for the advice though. I will try that.

It didn't work.

 

[chanzer]

If someone has a Renogy MPPT controller with lithium-ion batteries, please help ?

 

[MisterSandals]

The E3 error is battery under voltage. So it sounds like the SCC requires higher voltage to start charging and stop complaining.

 

[Forbisher]

If someone has a Renogy MPPT controller with lithium-ion batteries, please help ?

Does your battery have a BMS?
Where and how are you using your battery?.
Ah?

 

[chanzer]

Does your battery have a BMS?
Where and how are you using your battery?.
Ah?

I am not using my battery at all : D . I am just trying to charge it. It has 0 things hooked up to it. It does not have a BMS currently because it is made entirely out of brand new 18650 batteries charged to the same voltage.

 

[chanzer]

The E3 error is battery under voltage. So it sounds like the SCC requires higher voltage to start charging and stop complaining.

The battery is at about 11.4V at the moment. Do you mean higher voltage from the solar panel? I am a bit confused how it could be too low from the battery.

 

[MisterSandals]

I think it means the SCC will not attempt to even charge it with the battery voltage that low. This sounds silly but that is what i get from the wording.

 

[chanzer]

I think it means the SCC will not attempt to even charge it with the battery voltage that low. This sounds silly but that is what i get from the wording.

It is charging. It just gives me an error at the same time.

 

[MisterSandals]

It is charging. It just gives me an error at the same time.

Thats a good sign. Maybe it will charge itself out of the low voltage condition?

Renogy 40A MPPT solar controller

Looking at it a different way, what is the input voltage from solar? Is it possible that that voltage is too low (not high enough above 12v, like maybe ~16v minimum).

Sorry, just brainstorming.

 

[chanzer]

Thats a good sign. Maybe it will charge itself out of the low voltage condition?


Looking at it a different way, what is the input voltage from solar? Is it possible that that voltage is too low (not high enough above 12v, like maybe ~16v minimum).

Sorry, just brainstorming.

It's ok. Thank you for the suggestion. I'm pretty sure it is not that, but I will check tomorrow.