Mpp solar inverter stops connecting pv panels

[OffgridinFL]

Not sure title is the best description. But here’s the issue I’m having the pv input just stops connecting and charging the batteries. I can’t seem to figure out any reason this is happening. All of the sudden it will just stop mid day (4 out of 7 days this week). Sometimes I see it come back others I need to do a full shutdown and restart and it will work fine again. Anyone see this before? The batteries are not fully charged, I see it happen anywhere between 26-29 v. It’s a 5048 model. Pic attached with what it looks like on the inverter.

Any ideas?

 

[pollenface]

What is the voltage of the batteries when this happens?

 

[OffgridinFL]

That’s part of the problem. I’m not always home when it happens. I’ve witnessed it twice. Once batteries were at 28v. Another time 26.6. I have bulk at 28 and float at 27.

 

[Mac6792]

This is the solar charger no longer seeing enough voltage from the panels and dropping them (like at night). What is your pv setup end to end

 

[OffgridinFL]

I have 20 260w panels. 2 panels in series each and then parallel. Runs around 60-70 volts.

I thought it might be something like that too. At night it doesn’t show panels on display at all though. Attached photo.

 

[Mac6792]

I think the 5048 requires a minimum of 60 volts to produce wattage. Is that 60-70 volts measured at the panels or at the Inverter. If I recall you have a very long run 100+ feet? Perhaps you have enough voltage loss to impact you

 

[OffgridinFL]

I do have a long run. Maybe I’ll series 3 then and boost voltage. Worth a try

 

[Sanwizard]

I do have a long run. Maybe I’ll series 3 then and boost voltage. Worth a try

I agree with Mac6792. Read the manual about "startup" voltage for that model.

 

[Mac6792]

I do have a long run. Maybe I’ll series 3 then and boost voltage. Worth a try

I'd try that. The first pic you posted is what my display looks like at dusk just as the voltage drops low enough to stop producing power. It can click on an off for about 10 minutes then the pv array icon disappears completely

 

[OffgridinFL]

Didn’t have a chance to up the voltage yet, but I did see it live today. Figured I was working remote so I set up by it to watch. Voltage is still up above requirements (which is 48). See pic still shows 76, when pv disconnect happened. Basically the inverter still sees panel show voltage but no watts coming in.
I think it may be hitting max battery charge and turning off the mppt . Or maybe battery bms cutting. Not sure on this as I’m no expert. But battery voltage on one battery hits 29.5 (other battery at 26.5) and it clicks off. When it comes down it usually clicks back on but sometimes not. I let it come down to 26 today and then did a shutdown. Turned back on and started pulling full power from panels back up to the 29.5.

Thoughts on this? Maybe this additional detail helps

 

[TomC4306]

Didn’t have a chance to up the voltage yet, but I did see it live today. Figured I was working remote so I set up by it to watch. Voltage is still up above requirements (which is 48). See pic still shows 76, when pv disconnect happened. Basically the inverter still sees panel show voltage but no watts coming in.
I think it may be hitting max battery charge and turning off the mppt . Or maybe battery bms cutting. Not sure on this as I’m no expert. But battery voltage on one battery hits 29.5 (other battery at 26.5) and it clicks off. When it comes down it usually clicks back on but sometimes not. I let it come down to 26 today and then did a shutdown. Turned back on and started pulling full power from panels back up to the 29.5.

Thoughts on this? Maybe this additional detail helps

I'm confused. A 5048 is a 48 volt device.

 

[OffgridinFL]

I'm confused. A 5048 is a 48 volt device.

I run 2 24v wolf in series to get the 48v battery required.

Technically I would be running 4 total. 2 sets of 2 wolf 24 in parallel and put in series to hit 48v, but I have issues with two so they are not connected currently

 

[Mac6792]

Yes but in your post above one battery is 29v and the other is 26v. If that is in fact the case that's a no go. They should be balanced

 

[OffgridinFL]

Yes but in your post above one battery is 29v and the other is 26v. If that is in fact the case that's a no go. They should be balanced

Yeah. They should from my understanding, but they don’t. (Ongoing concerns I’ve had with the big battery wolf 24v. Product). But as long as they are above the requirements of the inverter they work. And I get a good amount of power out of them, I just don’t think I’m getting full capacity from one of them. I’ve done resets on bms but it won’t exceed 26.6. They do begin to balance out as they draw down at night. They end up .1 or .2 difference. If you know a way to balance them I’d love to know how.

Before when I had 4 working each group of 2 in parallel did balance at least according to the display on the batteries (I question the accuracy of that though, if I disconnect them I find they have different individual voltage).

This is my first time going solar so I may be misunderstanding something basic though.

 

[mesquito_creek]

According to BB... the batteries must be within .3 volts of each other before you connect them together in parallel to make them behave as a battery bank. Since you are in a series to achieve 48v, perhaps you have a similar issue where the BMS is not happy with what you are asking it to do. I would draw down one battery until both batteries are matched in Voltage and are matched while at rest for a while with no load or input... Then connect in a series to ask them to behave as a single 48V battery. You would probably need to have all four matched when you parallel the second set of batteries to have 2 48v batteries in parallel via the four units.

I tried for days to try to trick my 4 BB hsky into thinking they are part of a battery bank with no success. Once I slowed down and fully matched all four battery voltages, completely shut down my PV array, turned off my inverter did I achieve my desired results. First I connected all batteries in parallel, then I turned on the inverter, added the PV input and turned on the breaker panel to distribute the load... After all that all my batteries BMS track up and down within .3 v and I haven't touched it for over a month and a half.

I have the same manufacturer equipment mpp 6048v and BigBatteries.... But your 24v battery bms might require a different voltage delta than .3. I worked with BB via the technical chat and they were very helpful. Once I finally followed their instructions verbatim it all worked.

 

[WalterM]

When it disconnects try increasing the load by turning on the electric stove to lower the voltage and see if it turns back on. I suspect that your HV disconnect is shutting you off. Or the BMS is shutting you off when you hit 29.5v. Assuming LiFePo4 batteries.

 

[OffgridinFL]

According to BB... the batteries must be within .3 volts of each other before you connect them together in parallel to make them behave as a battery bank. Since you are in a series to achieve 48v, perhaps you have a similar issue where the BMS is not happy with what you are asking it to do. I would draw down one battery until both batteries are matched in Voltage and are matched while at rest for a while with no load or input... Then connect in a series to ask them to behave as a single 48V battery. You would probably need to have all four matched when you parallel the second set of batteries to have 2 48v batteries in parallel via the four units.

I tried for days to try to trick my 4 BB hsky into thinking they are part of a battery bank with no success. Once I slowed down and fully matched all four battery voltages, completely shut down my PV array, turned off my inverter did I achieve my desired results. First I connected all batteries in parallel, then I turned on the inverter, added the PV input and turned on the breaker panel to distribute the load... After all that all my batteries BMS track up and down within .3 v and I haven't touched it for over a month and a half.

I have the same manufacturer equipment mpp 6048v and BigBatteries.... But your 24v battery bms might require a different voltage delta than .3. I worked with BB via the technical chat and they were very helpful. Once I finally followed their instructions verbatim it all worked.

Thanks appreciate the feedback. I’ll give this a go.

I’ve been working with there tech support on the other two batteries. Did you ever have one of the batteries drain too far down. It won’t turn on. Tech support is saying I need to get a charger and individually bring each battery back to life. But I don’t see any chargers that would work with the Anderson connectors. They have been somewhat helpful but didn’t answer this inquiry.

 

[mesquito_creek]

Thanks appreciate the feedback. I’ll give this a go.

I’ve been working with there tech support on the other two batteries. Did you ever have one of the batteries drain too far down. It won’t turn on. Tech support is saying I need to get a charger and individually bring each battery back to life. But I don’t see any chargers that would work with the Anderson connectors. They have been somewhat helpful but didn’t answer this inquiry.

No I have never run them past the recommended low voltage cut off.... you should be able to scab one of your Andersen’s out of your system and bolt on something that will adapt to a charger

 

[msiliezar]

i have 2 of the litime 24v batts and i have the same 5048 lv controller. As the batts get full during the day it shuts down solar and drains the batts. Once batts hit cut off voltage of option 12 which is 51 volts. Then solar starts again charging and providing to loads. I hate this. I like batts to stay fulll and continue to use solar till sun down.

 

[Sanwizard]

i have 2 of the litime 24v batts and i have the same 5048 lv controller. As the batts get full during the day it shuts down solar and drains the batts. Once batts hit cut off voltage of option 12 which is 51 volts. Then solar starts again charging and providing to loads. I hate this. I like batts to stay fulll and continue to use solar till sun down.

That sounds like a parameter setting issue. IE: SBU. If solar is available, it should just charge the batteries to the float voltage, and keep supplying the loads until solar cannot.