Renogy Rover 40A - need help programming 24V 200ah LiFeP

[2p4d1van]

Need some help with a Renogy Rover 40A. I've got a 24V 200ah LiFeP battery. I'm only running 24V DC along with a step down to 12V DC. The 24V powers my fridge/freezer and a small 24V A/C. The 12V powers phones, laptops, fans, and small appliances. No 110V AC, so no inverter. I managed to set the Renogy to 24V and LiFeP, but I believe it's over charging the battery. The battery voltage climbs to around 27.4 to 27.7 and then the battery indicator begins fast flashing white, voltage flashes 29 to 30 and then it shuts down. Within seconds it restarts charging at around 26.5 and performs the same cycle again. I've been throwing the panel disconnect switch and leaving it off, until the battery drops below 24. I assume I need to program the controller to correct this, but just not sure how or what to change. Can someone here give me some help in correcting this?

I've attached the battery specs

Thanks, Steve

 

[mikefitz]

It's most likely the BMS detecting cell over volts and shutting down the charge path. Often happens with ready built batteries and high charge voltages. Its not helped by the fact that the Rover Controllers are often not calibrated correct and produce higher voltages than set and shown on display.
Sent the charge voltage to just below the voltage where there are problems, say 27.5 volts, ( or lower if the problem persists).
This is still a voltage that will charge to over 90%.
Once you have found a voltage that's stable increase the absorbtion time. As you use and cycle the battery it will become more in balance. There is no advantage in charging at avoltage over 28.0 volts.
It would be useful to confirm with a meter the voltages produced by the controller.

The settings that determine charging are,
Equalisation volts, set the same as Boost volts
Boost volts, this the charging voltage target used in the bulk stage, (absorbtion voltage), set as suggested, 27.5 volts
Float volts, set as the rest volts of the battery, 26.8 volts, slightly higher if the battery is loaded during the solar day, 27.0 volts
Boost return, 0.2 volt lower than float volts
Equalisation duration, set to zero
Boost duration, absorbtion period, set to 60 minutes, once the battery is better balanced reduce to 10 minutes

Note with the possible poor calibration of the unit you need to confirm the actual voltages with a resionably accurate meter.


Mike

 

[2p4d1van]

From the BT app, I went to the settings screen. Correct me if I am wrong. If I have selected 24V as the system voltage and the current setting for Boost is 14.4V, that would give me a 28.8 Boost. If so, I would need to change the Boost voltage to 13.75V in order to achieve a Boost setting of 27.5V.

So, I should set the Boost and Equalization to 13.75V, and the Float to 13.4V. I don't see a setting listed for the Boost return, or Equalization duration. There is a Boost Duration that is currently set to 0min. Are these settings hidden somewhere.

I'm in transit and won't get a chance to check voltages with a meter until late tonight.

Thanks for your help with this. This is my first venture into solar, so it's a learning experience.

 

[2p4d1van]

I finally realized that the "User" mode is accessed through the battery type selection. Got the parameters changed. Using the buttons on the unit, I did not see the ability to set a Boost Duration. I did see that listed in the BT app settings, however, I have yet to figure out how to use the app to change the parameters.

 

[Dynoman]

Need some help with a Renogy Rover 40A. I've got a 24V 200ah LiFeP battery. I'm only running 24V DC along with a step down to 12V DC. The 24V powers my fridge/freezer and a small 24V A/C. The 12V powers phones, laptops, fans, and small appliances. No 110V AC, so no inverter. I managed to set the Renogy to 24V and LiFeP, but I believe it's over charging the battery. The battery voltage climbs to around 27.4 to 27.7 and then the battery indicator begins fast flashing white, voltage flashes 29 to 30 and then it shuts down. Within seconds it restarts charging at around 26.5 and performs the same cycle again. I've been throwing the panel disconnect switch and leaving it off, until the battery drops below 24. I assume I need to program the controller to correct this, but just not sure how or what to change. Can someone here give me some help in correcting this?

I've attached the battery specs

Thanks, Steve

The Renogy Rover 40 only has settings for 12 volt systems. For 24 volt systems double the values to get the actual settings. Example for a 28 volt boost setting set the controller for 14 volt boost.

I find the Rover 40 can be off by 0.1 or 0.2 volts or more and this is common with this solar charge controller. So if boost set for 14 (28) volts it may go to 28.1 or 28.2 volts. Keep this in mind when making settings especially boost & float.

Sounds like your BMS is cutting off the battery around 27.5 or 27.6 Volts. Probably because the cells are not top balanced very well. As was suggested set your boost to 27.4 to 27.6 Volts to start. Once several charge cycles have taken place the cells should be in better top balance and boost voltage can probably be slowly increased to 28 volts.

Note: With a balancing current of only 35ma it will probably take some time and a number of charge cycles to top balance the cells good. Also the BMS will only balance cells when they are above 3.4 volts or 8 x 3.4 = 27.2 volts. So Boost needs to be above 27.2 volts to even start the top balancing process.

Your BMS in your battery will (or should) shut down your battery before any damage to the cells with overvoltage or undervoltage protection, but you don't want to use this feature to run your solar system since it is a failsafe. You need to program the Rover 40 Boost Voltage to a voltage below your BMS overvoltage and you need to turn off your loads before the battery BMS goes into undervoltage.

Min voltage for LiFePO4 Cells is usually 2.5v or 8x 2.5 = 20 Volts and Max voltage for LiFePO4 Cells is usually 3.65v or 8x 3.65 = 29.2 Volts
Your BMS may cut out before the Min or Max Voltage depending on how it is programmed and how well the cells are top balanced, but you don't want to exceed the Min or Max and really keep a buffer above the min and below the max.

The Rover 40 is not a precise SCC, but given its price point and the BT and ability to program and monitor on your phone it is a good value for entry/small solar systems. After some time (going on my 3rd year) I have learned to use it well. Just have to know its limitations...

I use the Renogy BT-1 Bluetooth Module that plugs in the Rover-40 Rs232 port.
www.amazon.com/Renogy-Bluetooth-Module-Communication-Controllers/dp/B0894SDTSL

With that Module I use the Renogy BT App loaded on my phone to program the settings and monitor the Rover-40 and is free. The app allows many parameters to be set in USR battery setting. See the attached manual.

‎Renogy BT

‎APP for solar charge controller operation in smart PV power system. It's for solar charge controller working parameter setting and reading. All data can be displayed in a diagram. Meet the Renogy BT. a convenient way to manage and monitor your solar power system all in the palm of your hand...

apps.apple.com

Renogy BT - Apps on Google Play

a convenient way to manage and monitor your solar power system

play.google.com

To program the Rover 40 with the Renogy BT app select Settings at bottom of the screen. Once in Settings ensure Battery button is selected (not Load) & click the Read button to display the current Rover settings. Next click the Set button and then click Confirm and input default password which should be 135790123 and click Confirm. Now change the desired settings and then click the Set button. The changes should now be made. Check the settings were changed by clicking the Read button.

I am using the the following USR settings. The Rover LI settings are to aggressive for Lifepo4 Batteries.
Set to USR & set:
Note: For 24 volt systems values will be doubled automatically when SCC running program.
High Voltage Disconnect 14.5v
Charge Limit Voltage14.1v Note: Set to 13.8 or 13.9 to start.
Equalization Charge Voltage 14.0v
Boost Charge Voltage 14.0v (also called Absorption) Note: Set to 13.7 or 13.8 to start and slowly increase after several charge cycles.
Float Charge Volt 13.6v -Set to 13.4 to start-
Boost Char Return Volt 13.2v
Over Disc Return Volt 11.0v
Low voltage Alarm 10.9v
Over Discharge Volt 10.5v
Discharge Limit Volt 10v
Over Disc Delay Time 5s
Equalization Charge Time 0 Min
Boost Time 10 Min Note: Set to 60 min or more to get cells to top balance to start and decrease to 10 min once cells are well top balanced.
Equalize Charge Interval 185 (Note this value cannot be 0 because controller will get stuck in boost mode)
Temp Comp 0A

Unplug temp sensor from the Renogy-40 amp Solar Charge Controller. It is used for lead acid batteries.

These settings should get you started. You can adjust from there. Over time you will find the best settings for your system

See the attached manuals.

Hope this helps...

 

[2p4d1van]

The Renogy Rover 40 only has settings for 12 volt systems. For 24 volt systems double the values to get the actual settings. Example for a 28 volt boost setting set the controller for 14 volt boost.

I find the Rover 40 can be off by 0.1 or 0.2 volts or more and this is common with this solar charge controller. So if boost set for 14 (28) volts it may go to 28.1 or 28.2 volts. Keep this in mind when making settings especially boost & float.

Sounds like your BMS is cutting off the battery around 27.5 or 27.6 Volts. Probably because the cells are not top balanced very well. As was suggested set your boost to 27.4 to 27.6 Volts to start. Once several charge cycles have taken place the cells should be in better top balance and boost voltage can probably be slowly increased to 28 volts.

Note: With a balancing current of only 35ma it will probably take some time and a number of charge cycles to top balance the cells good. Also the BMS will only balance cells when they are above 3.4 volts or 8 x 3.4 = 27.2 volts. So Boost needs to be above 27.2 volts to even start the top balancing process.

Your BMS in your battery will (or should) shut down your battery before any damage to the cells with overvoltage or undervoltage protection, but you don't want to use this feature to run your solar system since it is a failsafe. You need to program the Rover 40 Boost Voltage to a voltage below your BMS overvoltage and you need to turn off your loads before the battery BMS goes into undervoltage.

Min voltage for LiFePO4 Cells is usually 2.5v or 8x 2.5 = 20 Volts and Max voltage for LiFePO4 Cells is usually 3.65v or 8x 3.65 = 29.2 Volts
Your BMS may cut out before the Min or Max Voltage depending on how it is programmed and how well the cells are top balanced, but you don't want to exceed the Min or Max and really keep a buffer above the min and below the max.

The Rover 40 is not a precise SCC, but given its price point and the BT and ability to program and monitor on your phone it is a good value for entry/small solar systems. After some time (going on my 3rd year) I have learned to use it well. Just have to know its limitations...

I use the Renogy BT-1 Bluetooth Module that plugs in the Rover-40 Rs232 port.
www.amazon.com/Renogy-Bluetooth-Module-Communication-Controllers/dp/B0894SDTSL

With that Module I use the Renogy BT App loaded on my phone to program the settings and monitor the Rover-40 and is free. The app allows many parameters to be set in USR battery setting. See the attached manual.

‎Renogy BT

‎APP for solar charge controller operation in smart PV power system. It's for solar charge controller working parameter setting and reading. All data can be displayed in a diagram. Meet the Renogy BT. a convenient way to manage and monitor your solar power system all in the palm of your hand...

apps.apple.com

Renogy BT - Apps on Google Play

a convenient way to manage and monitor your solar power system

play.google.com

To program the Rover 40 with the Renogy BT app select Settings at bottom of the screen. Once in Settings ensure Battery button is selected (not Load) & click the Read button to display the current Rover settings. Next click the Set button and then click Confirm and input default password which should be 135790123 and click Confirm. Now change the desired settings and then click the Set button. The changes should now be made. Check the settings were changed by clicking the Read button.

I am using the the following USR settings. The Rover LI settings are to aggressive for Lifepo4 Batteries.
Set to USR & set:
Note: For 24 volt systems values will be doubled automatically when SCC running program.
High Voltage Disconnect 14.5v
Charge Limit Voltage14.1v Note: Set to 13.8 or 13.9 to start.
Equalization Charge Voltage 14.0v
Boost Charge Voltage 14.0v (also called Absorption) Note: Set to 13.7 or 13.8 to start and slowly increase after several charge cycles.
Float Charge Volt 13.6v -Set to 13.4 to start-
Boost Char Return Volt 13.2v
Over Disc Return Volt 11.0v
Low voltage Alarm 10.9v
Over Discharge Volt 10.5v
Discharge Limit Volt 10v
Over Disc Delay Time 5s
Equalization Charge Time 0 Min
Boost Time 10 Min Note: Set to 60 min or more to get cells to top balance to start and decrease to 10 min once cells are well top balanced.
Equalize Charge Interval 185 (Note this value cannot be 0 because controller will get stuck in boost mode)
Temp Comp 0A

Unplug temp sensor from the Renogy-40 amp Solar Charge Controller. It is used for lead acid batteries.

These settings should get you started. You can adjust from there. Over time you will find the best settings for your system

See the attached manuals.

Hope this helps...

This is awesome! I didn't realize it, until I opened the BT manual that you attached, but the app I had downloaded was an impostor called DC Home. That was the reason why I could not find half the settings you had previously mentioned. Now that I have made all the changes, is there a "save" button? Or, do I simply close the app?

 

[2p4d1van]

Or, do I change from USER to LI?

 

[2p4d1van]

Click "Set". The first time I did that, it didn't save and returned to the default settings. I re-entered and tried a second time and it saved.

Thanks for all the help. My apologies if I'm a little slow with this stuff. I'm definitely a "newbie" at solar. If I was just wiring a hot rod from front to back and creating my own harness....that's easy for me. With time, I'm sure I will adapt to the solar process.

 

[Dynoman]

Click "Set". The first time I did that, it didn't save and returned to the default settings. I re-entered and tried a second time and it saved.

Thanks for all the help. My apologies if I'm a little slow with this stuff. I'm definitely a "newbie" at solar. If I was just wiring a hot rod from front to back and creating my own harness....that's easy for me. With time, I'm sure I will adapt to the solar process.

Glad to hear it worked. The tricky part will be to set the boost high enough above 27.2 volts so that the balancing is enabled, but below where the run away cell gets above 3.65 volts and the BMS shuts down the battery. 27.4 volts boost is probably a good place to start. Have it hold boost for at least an hour to start to top balance the battery and lower the time to 10 minutes once the boost is able to stabilize around 28volts. With only 35ma or 0.035 amps of balance current it will probably take a while to get there.

 

[Philliplazer]

Hello I have a 24 lithium Iron system with the Renogy 30 and I copied all your specifications I haven’t seen boost or float actually turn on it has been constantly on MPPT charging am I meant to change something because it only seems to be charging up to about 26.3 if I have about 500 W coming in it might go to about 27 but as soon as the sun goes down it will drop back down to 26.3 I haven’t seen the boys to come on once is there something I’m doing wrong I did your settings last night do I have to wait a few cycles?

 

[Dynoman]

Hello I have a 24 lithium Iron system with the Renogy 30 and I copied all your specifications I haven’t seen boost or float actually turn on it has been constantly on MPPT charging am I meant to change something because it only seems to be charging up to about 26.3 if I have about 500 W coming in it might go to about 27 but as soon as the sun goes down it will drop back down to 26.3 I haven’t seen the boys to come on once is there something I’m doing wrong I did your settings last night do I have to wait a few cycles?

Welcome to the DIY Solar Power Forum.

My Renogy Rover Solar Charge Controllers stay in MPPT charging most of the time during the day this time of year (Winter) and rarely do I see Boost or Float. December & January are the worst for solar production in my area with the sun low in the sky and lots of cloudy days. Starting in February and March conditions improve and once summer begins my system goes into boost and then float almost every day.

If you are using the Renogy Rover Boost settings of 14 volts (which is 28 volts for a 24 volt Lifepo4 battery) listed in the previous message #5 of this thread your system will not go into Boost until approximately 28 volts is reached. Once in Boost the Rover should hold it around 28 volts for about 10 minutes and then go to float mode of about 27 volts until the sun goes down (if using the settings listed in message #5).

Click on this link to read this message for more information when using he Renogy Rover Solar Charge Controller. Also read the thread the message is in for more good information

Renogy 40a mppt Li settings

Thanks for the info, I get no heat from the 2 awg wire so that's good for me. Just ordered a 40a circuit breaker to go between the charge controller and batteries plus the Blue Sea 5191 terminal block and 200a fuse today. The 8 guage is less than 2 feet and I did find a little heat when the...

diysolarforum.com

Hope this helps...

 

[Philliplazer]

Yes it helps a bit I am in Australia it is currently going into summer and I am getting quite a bit of sun I have two 120 amp lithium iron batteries 12 V combined to make 24 V and I have to 350 what panels and even with it pulling in almost 500 W it still doesn’t go into boost do I need more Solar panels ?

 

[Dynoman]

Yes it helps a bit I am in Australia it is currently going into summer and I am getting quite a bit of sun I have two 120 amp lithium iron batteries 12 V combined to make 24 V and I have to 350 what panels and even with it pulling in almost 500 W it still doesn’t go into boost do I need more Solar panels ?

Yes, more solar panels would help and according to the Renogy Rover Manual (see attached) the Rover 30 amp can handle 800 watts of panels with a 24 volt battery.

It is amazing your system is getting 500 watts of power from 350 watts of panels. Usually about the best is 80 to 90% from the panels which would be 350w x .90%= 315 watts. Sometimes the panels will output more briefly on partly cloudy days when the sun pops out from a cloud because the sun bounces off the earth then the clouds and back to earth. Normally on full sun days the 350 watts of panels will not produce much more than about 320 watts.

It would be best to know your solar system to help further:
1) Do you have the Renogy Rover 30 MPPT Solar Charge Controller?
2) Do you have an Inverter? If so model & watts
3) What brand & model of solar panels do you have? What is open circuit (VOC)? What is Short Circuit Current (Isc)? Maximum Power Watts?
A picture of the sticker on the back of the panel(s) would be best, but the values asked for will be enough.
3a) How many the solar panels? If more than 1 how are they wired? Series, Parallel, Series Parallel? Often times multiple panels are wired in series with (-output of a panel to +input of next panel)
4) What batteries do you have? brand & model
5) What are the loads that are being supplied by the solar system.