Wrong default settings of Renogy DC/DC converter for LFP?

[Michi]

Hi all,

I'm new in this forum and I'm a swiss! Therefore sorry for my bad english!
I build my own 100Ah LiFePo4 battery with Dali BMS and set the BMS according to the datasheet of the batterie supplier. Max cell voltage 3.65V and max. battery voltage 14.4V. Now, I charged up the battery with the Renogy DC/DC MPPT charger (RBC50D1S) and the BMS turned off at 14.4V. So far so good but in my opinion this should not be the job of the BMS! In regular operation the charger should turn off before the BMS cuts the voltage. I set the charger to LFP but according to the charging parameters in the user guide the boost voltage is set to 14.4V and the charging limit voltage to 15.5V. This means all components are working in the definied range. The default values of the renogy charger are way too high for LFP in my opinion or do I understand something wrong?

Thank you in advance for your help.

Best, Michi

 

[Tomthumb62]

Yes I believe there is a defect with the default setting on these renogy devices.

On mine, the default setting for High Voltage Disconnect on USER mode is 17v. This will damage your BMS if done repeatedly.

There is no way to change this setting without special equipment.

I’m trying to get a refund from Renogy for this defect.

 

[Michi]

Thank you for the quick feedback! Is it possible with the BT2 and the renogy app to define my owm charging parameters? called user profile in the user guide. This should fix this issue!

Does somebody knows if there is an PC software available instead of the renogy app?

 

[Tomthumb62]

Thank you for the quick feedback! Is it possible with the BT2 and the renogy app to define my owm charging parameters? called user profile in the user guide. This should fix this issue!

Does somebody knows if there is an PC software available instead of the renogy app?

You need to use the older app called Renogy BT. The newer DC Home app won’t allow you to change all the settings. They’re planning on pulling the older app in the future so another reason I am just done with Renogy. Except their panels are decent.

Edit: yes you need the Bluetooth adapter if that wasn’t obvious. My device uses the BT-1, but I assume the BT-2 works similar for the devices that require that model.

 

[Michi]

Thanks! I'll order the BT2 and try to create my own charger profile. I'm curious that the standard LFP profile from renogy doesn't fit to the most of the cells....

 

[Rednecktek]

One thing I've noticed with a few MPPT controllers lately is that they come from the factory as FLD or SLA and when you change the profile it retains the FLA settings resulting in either under charging or high voltage alarms. Going to USR, setting the voltages, and then back to LFP has become a standard practice now.

 

[EnsignR]

You need to use the older app called Renogy BT. The newer DC Home app won’t allow you to change all the settings. They’re planning on pulling the older app in the future so another reason I am just done with Renogy. Except their panels are decent.

Edit: yes you need the Bluetooth adapter if that wasn’t obvious. My device uses the BT-1, but I assume the BT-2 works similar for the devices that require that model.

FWIW you can also set the user parameters with the RMS-DCDC screen. They list it and BT-2 as optional, but really I think you absolutely need one of them. It's a shame that they don't have a third option of combining the two into one device - a screen that also lets you connect with your phone via Bluetooth.

 

[Tomthumb62]

FWIW you can also set the user parameters with the RMS-DCDC screen.

Yes but.

You can only set some of the parameters, not all, including High Voltage Disconnect. HVD will cause the controller to disconnect from the battery if the voltage reaches that setting (default is 17v!!). Which on my Renogy controller, this happens at least a few times a day. Check your history, on the Renogy BT app, which shows the longest amount of history, to see what the highest battery voltage has been over the last few weeks. On my end, it was shockingly high, 16-18v at times, many times a day. Until I got the Bluetooth dongle and was able to see and change the setting in USER mode.

@Dynoman has explained that while this high battery voltage is concerning, it might not actually be that the battery itself reached that voltage, but the controller thinks it did. Yet another reason to get rid of this piece of garbage and never deal with Renogy again.

I’ve been in touch with Renogy tech support for a couple of weeks now. While they’re friendly and seem willing to help, they are very slow to do anything. They ask for screenshots and I send them. They say they’ll call back that day never do. They pass the buck to yet another tech agent, who is low level and unable to do anything. They ask for the info about the problem, which I’ve written out in detail and with screenshots but they seem unable or unwilling to actually read my contributions to the support ticket.

The MPPT is now four years old. I believe it is working as it was designed. It’s just a very bad design. I will try to sell it and buy a Victron. I am DONE with Renogy.

Sigh.

 

[EnsignR]

Yes but.

You can only set some of the parameters, not all, including High Voltage Disconnect.

I see. I'll be interested to know if/how your support ticket is resolved.

 

[Tomthumb62]

I see. I'll be interested to know if/how your support ticket is resolved.

At this point, I’ve decided not to waste any more time with Renogy support. It’s been back and forth about 7 times now and all they’ve said is they’ll help me. But have provided no tangible help so far. They’re very nice and seem willing to help, they just can’t seem to do so nor read my messages where I send them info they ask for.

“Hello there, can I get your name?”

“Tom.”

“Thank you for that information. Let’s get your resolution today. Before we do that, I’d like to get some basic information from you to help you best solve your problem. Is that alright?”

“Yes, sure.”

“Okay, to get started, can I please get your name?”

“Tom.”

“ Ok, great, thank you for that information. And once more, can I please get your name.”

(I’m exaggerating a bit, but perhaps you get the point. It’s maddening.)

I just ordered a Victron 100/30 controller to replace this one. Will be very glad to do so.

 

[Alpineman]

I'm having simmuilar issue with my Renogy MPPT charger and there tech help has been no help they just reads everything out of the instructions manual which I have done no help, I'm done with Renogy and will not purchase any of there products.