Renogy Rover Li stuck/reset to 12V on 24V bank

[pbusque]

Hello,
I recently purchased Renogy Rover Li charge controller and I would like to know if this scenario has occurred to anyone else, or if I inherited a citrus.

My setup is a 600w / 48v solar panels.
I have 2x EcoWorthy LiFePO4 12volts batteries in series, so a 24 volts bank.

When I first installed the Rover, It was flashing in overcharge mode. It came as Li-12V by default.
When trying to change it to Li-24V mode, it would refuse to save the setting, always reverting to 12V when leaving the menu,
No matter what, it would stick to 12V. In order to change and save the setting, I had to:
Unplug the bank. Plug a 12 volts battery to the Rover, and switch to 24 Volt. Unplug the 12V battery and plug the bank back.

In other word, it wouldn't save any setting if it was in any error mode. Not convenient if the error is already in place and not the result of a bad input.

Now the Rover work! It would have been OK if it was a one time change, but I returned to my cabin 3 weeks later, only to discover the Rover in ACR mode, which is when the controller is powered only by the solar.

Turning the solar off, the Rover would display being in Overcharge mode (thus disconnected from the bank AND entering ACR mode) as it had reset itself back to 12volt.

Again, same procedure: Unplug the bank, plug 12V battery, change settings, plug the bank.

Has anyone ever had this issues? Is it a 'known' problem with the Rover? Or do I have a defective one?

Thanks
Philippe

 

[Whinny]

Two 12v batteries in series commonly causes issues unless you have a balancer between them. Check the state of charge on both batteries or charge them both fully with a 12v charger before looking at the controller.

 

[pbusque]

Two 12v batteries in series commonly causes issues unless you have a balancer between them. Check the state of charge on both batteries or charge them both fully with a 12v charger before looking at the controller.

Both battery were fully charged individually before the installation.
The controller also is working normally when successfully set into 24 volts mode, through the bank switching method.

 

[Whinny]

Check the voltage at the controller with a known good meter and compare to the Renogy displayed voltage. Certain firmware versions of the SRNE controllers reads high. If so you may wish to use user mode to set charging parameters lower-that is generally recommended anyways.
Have you seen this ......

Troubleshoot ACr

Lithium batteries with a battery management system (BMS) typically have a protection feature against abuse or inoperable conditions.

www.renogy.com

 

[Suijkerbuijk]

You have to set auto detect .
Not select 12 or 24 volt.
You set on a 12 volt battery and than Select 24 volt.
That unit see on that moment 12 volt and the selection is not save.
So you have parameter error.

Look for the Manuel online by renogy how to select auto detect

 

[Suijkerbuijk]

Both battery were fully charged individually before the installation.
The controller also is working normally when successfully set into 24 volts mode, through the bank switching method.

No .
Not if the one bms shutdown by over charging .
It disconnect and the volt go down on that moment.
New battery have to balance fist .
And do this by Charging with a charger till all cells hit 3.65volts (you have sometimes disconnect and connect the charger again)
After both battery are done by a 12 volt charger.
Than you set them in series.
And charge again with the 24 volt charger .
So all cells will be balance again.
The best is use a slow charger to do so.
A 3a charger is fine for the last top balance the cells.

Than you set the mppt controller

So max charge profile will be 28 volts (cell will be 3.5volts ) on that mppt by bulk charging.
Or if you have a good battery you can go to 28.4volts.
Again by 27.2 volt the battery is for 99.999% full
It do not have to be higher than that
So your float charge will be 26.4 volt

If you use the beult in programma from renogy , epever or what brand than ook. (Not Victron)
You see that the max bulk charge will be 29.2 volts on a 24 volts battery setup.
That is to high and the bms shutdown.
The cell are on 3.65 and if you have out of balance cells even just one the bms shutdown

You Program the mppt that you do not use the bms of the battery that it go in to protect.
Some people do that.
But personal i do not like it just for that small extra on the battery.
I still think that a bms is the last resort to protect the cells from to go to high or to low.
And the best use is to never go to that point.
This my personal thinking about it.

 

[mikefitz]

Is it a 'known' problem with the Rover?

There seem to be problems with all Renogy products, and the Rover is high on the list. Many change to Victron controllers and have a much less stressful life.
Leaving aside the set up for the moment, the fact that it looses the settings is most likely due to one of the series batteries entering protection. The resulting lack a battery true volts confuses the controller.
Putting two 12v batteries is series, especially if they are new low cost, ( and thus out of balance), frequently causes issues.
Reduce the charge volts to 28.0 or even 27.6 volts and fit a min point balancer/ equiliser.

Battery Balancer - Victron Energy

Equalize the state of charge of two series connected 12V batteries using the Battery Balancer. Find a Victron Energy dealer near you.

www.victronenergy.com

The set up should be, ( according to the user manual).
Connect to the battery, manually via the display set up the system voltage for lithium, (auto voltage set up only for lead batteries)
Any modification of charge values are made as if its a 12v system, the unit auto doubles the value.
(page 45 46 in the manual).

 

[sirtra]

Hello,
I recently purchased Renogy Rover Li charge controller and I would like to know if this scenario has occurred to anyone else, or if I inherited a citrus.

My setup is a 600w / 48v solar panels.
I have 2x EcoWorthy LiFePO4 12volts batteries in series, so a 24 volts bank.

When I first installed the Rover, It was flashing in overcharge mode. It came as Li-12V by default.
When trying to change it to Li-24V mode, it would refuse to save the setting, always reverting to 12V when leaving the menu,
No matter what, it would stick to 12V. In order to change and save the setting, I had to:
Unplug the bank. Plug a 12 volts battery to the Rover, and switch to 24 Volt. Unplug the 12V battery and plug the bank back.

In other word, it wouldn't save any setting if it was in any error mode. Not convenient if the error is already in place and not the result of a bad input.

Now the Rover work! It would have been OK if it was a one time change, but I returned to my cabin 3 weeks later, only to discover the Rover in ACR mode, which is when the controller is powered only by the solar.

Turning the solar off, the Rover would display being in Overcharge mode (thus disconnected from the bank AND entering ACR mode) as it had reset itself back to 12volt.

Again, same procedure: Unplug the bank, plug 12V battery, change settings, plug the bank.

Has anyone ever had this issues? Is it a 'known' problem with the Rover? Or do I have a defective one?

Thanks
Philippe

Known problem (sort of), i'm running mine in 24v too and it seems to happen when the charge controller has no power for a while and the settings go back to defaults - i've had the same issue but it's a little easier to correct than may appear as it is actually saving the setting, you just have to then power cycle for it to go into 24V mode from 12V. Changing the setting alone won't do it.

So the step by step process i do is the following:

1) switch the breaker to the panels off (so there is no solar power coming in - if there is you can't power cycle the charge controller)
2) hold down the button to enter settings, alter it to 24V from 12V, press the button to exit settings (it will still be showing 12V once you exit settings but don't worry the setting did actually save)
3) switch the breaker to the battery off, wait a second or 2 for the charge controller to power off, then turn the breaker back on
4) charge controller should now be running in 24V mode and show this on the screen
5) switch the breaker to the panels on
6) use the mobile app assuming you have the BT2 add-on to tweak the voltage settings, it will always be presented as 12V here but when running in 24V mode it just doubles whatever is set. So if you set the over discharge voltage to 11.8 for example this will actually equate to 23.6 when running in 24V mode (this isn't essential as the defaults will work but i personally tweak mine)

What i've found is that even if the charge controller goes into over discharge mode when the voltage gets too low, my inverter does not (even when it's not inverting) and if left in this state for too long the parasitic drain eventually depletes the batteries to the point they enter de-activate or protection mode.. hence causing the charge controller to fully lose power and go back to default settings.

It's a bit of a PITA and a shame it only auto detects 12/24V when set to lead/AGM batteries - yet it defaults to Lithium as even if you where using 24V lead/AGM it would still require you to manually change settings to get back up and running.

I consider it a design flaw as the auto-detect 12/24V is effectively a useless setting, no matter what you'll need to manually alter settings after power loss unless you are running 12V lithium.

They really should have made it auto-detect 12/24V irrespective of the battery type and default to lithium as let's face it, hardly anyone uses lead/AGM these days, but even if they do, the auto-detect will be useless after power loss unless you manually change it over to lead/AGM first and if you don't, those lead/AGM batteries will be overcharged if you're using a 12V setup as it'll be charging them as Lithium! Not sure what they were thinking having it designed this way honestly.

You might be able to avoid this happening by increasing the over discharge voltage of the charge controller (so it stops drawing power earlier with the hope there is then enough left in the tank so to speak that even with parasitic drain from an inverter it maintains enough charge to keep the controller powered until there is sunlight. Likewise if you can alter the same setting of your inverter (unfortunately with mine you can't - i just added more battery capacity, haven't had an issue since but should the battery charge deplete low enough it will require manual fixing to get going again)


PS - the ACR on the screen is actually meant to represent ACT and is short for 'Activate' mode - it's what happens when the battery voltage is extremely low or not detected at all. It essentially just does very brief pulses of charge which should activate a battery which has gone into protection by the BMS for low voltage. Given you got this error/notification it somewhat confirms the batteries charge was drained so low the charge controller lost power and thus it's settings.