48v EG4 batteries reading very low amperage @ 42% SOC.

[AndrewG]

Having battery issues after snow covered panels.

System Specs: Off-grid
5000es Growatt Inverter/Controller
14 panels- 48v 365w 9.8 amp wired- 7x2 @ 19+amp- 3-eg4 batteries 100amp 48v 5Kw
2 rack & one LL - this is the one the BMS connects to the inverter.

Problem- Snow covered panels yesterday & drew system down to approximately 30% SOC. Lots of cloud cover today so low charging for 4 hrs. SOC climbed to 36% so I charged the system with a generator to bring batteries back up. Ran generator for 2+ hrs & brought SOC up to 46%.

After about an hour of just battery house usage, no gen, The system shut off entirely. Checked the LL battery for info and battery amperage read 0.4amps. What could be causing this? Batteries are in parallel I don’t understand the BMS indicating such a low reading.

Called SS earlier today because of a battery charging issue and they suggested some inverter setting changes, but it turned out the charging problem was bc the panels were totally covered in snow. At that time the Inverter showed 0.3amps/230v from panels covered in snow. Brushed off panels and got batteries up to the 46% SOC with PV & Gen mentioned earlier. Now, no power.

What should I be looking at now? Should I just try to top off the batteries with the generator in the morning? Gen spec is 9800w unit with a 240/50amp wired connection to inverter AC terminal.

Thank you in advance for any help.

Andrew

 

[Zapper77]

I'm slightly confused. Can you read your post and make it clearer.

This is what I read.

"Hay my panels are covered with snow and my batteries died, I removed the snow and everything is working."

 

[Zapper77]

You may be mixing up amperage and amp hour

 

[AndrewG]

Hello,

Woke this morning and turned on system to check amp reading. Just turned on the lead comm LL unit and it registered 8.5 amps. Flipped the breaker on the next battery and the amps started to drop immediately. Is this telling me the rack batteries have no charge or the bms is not working correctly. SS suggested changes to the dip switch settings yesterday to the following: First battery 3 down 1 up, second all down & third anything else. What is up?

I am not an electrical wiz just trying to figure out how a system that was working fine suddenly went bad. Now wondering if the 2 rack units in parallel were working prior? Thinking I’ll use a multimeter to check the 2 rack batteries and if they are all the way down take them out of the system and charge them with a 48v charger independently of the system. If they come back up put them back into the system, thoughts?

Thank you,

Andrew

 

[pvgirl]

What is going on with the inverter? There doesn't seem to any thing obviously wrong on the battery side, if the inverter isn't charging or discharging from the battery there won't be any amps registering.

 

[Zapper77]

Why are you turning off the batteries?

 

[Zapper77]

Hello,

Woke this morning and turned on system to check amp reading. Just turned on the lead comm LL unit and it registered 8.5 amps. Flipped the breaker on the next battery and the amps started to drop immediately. Is this telling me the rack batteries have no charge or the bms is not working correctly. SS suggested changes to the dip switch settings yesterday to the following: First battery 3 down 1 up, second all down & third anything else. What is up?

I am not an electrical wiz just trying to figure out how a system that was working fine suddenly went bad. Now wondering if the 2 rack units in parallel were working prior? Thinking I’ll use a multimeter to check the 2 rack batteries and if they are all the way down take them out of the system and charge them with a 48v charger independently of the system. If they come back up put them back into the system, thoughts?

Thank you,

Andrew

When ever you reconnect (turn on the breaker) your three batteries will attempt to balance the voltage between them.

 

[AndrewG]

Why are you turning off the batteries?

I turned the entire system off when it stopped working.

 

[400bird]

There's not much useful information to go on. When the system shut down, there should have been an alarm somewhere, battery, inverter, something.

When was the last time you batteries reached 100% and completed a charge cycle?

Yes, you should clear the snow from the panels of you want them to make power.

 

[AndrewG]

What is going on with the inverter? There doesn't seem to any thing obviously wrong on the battery side, if the inverter isn't charging or discharging from the battery there won't be any amps registering.

Hello,

As you can see from the photos & accompanying info. The batteries dropped amperage from the 8.5A to 1.0A in a matters of 30 seconds once I flipped the second battery on. Is this a normal occurrence? Once the batteries hit .5A the system shut down no current from batteries to the inverter.

What is going on with the inverter? There doesn't seem to any thing obviously wrong on the battery side, if the inverter isn't charging or discharging from the battery there won't be any amps registering.

 

[AndrewG]

There's not much useful information to go on. When the system shut down, there should have been an alarm somewhere, battery, inverter, something.

When was the last time you batteries reached 100% and completed a charge cycle?

Yes, you should clear the snow from the panels of you want them to make power.

There was no noted alarm from batteries or inverter. Batteries where 100% a week ago. Snow was cleared and amperage from panel array was up to 2.4 amps in fading light. What the issue is in the battery system where bringing them all online in sequence pulls the amps below 1A on the system and shuts off battery power to the inverter. I called SS and they said that the two rack batteries where likely discharged. We are off grid and have very little contestant load to the inverter usually reads around 5% so I question how 2 5kw batteries would drain in 3 days. Any thoughts?

 

[400bird]

Hello,

As you can see from the photos & accompanying info. The batteries dropped amperage from the 8.5A to 1.0A in a matters of 30 seconds once I flipped the second battery on. Is this a normal occurrence? Once the batteries hit .5A the system shut down no current from batteries to the inverter.

Battery, you've only got a picture and current from one battery. Not the entire stack. When you turned on the second battery, the current likely went into that battery, not the first.

You need to measure the voltage and make sure they are close before switching on more batteries.

There was no noted alarm from batteries or inverter. Batteries where 100% a week ago. Snow was cleared and amperage from panel array was up to 2.4 amps in fading light. What the issue is in the battery system where bringing them all online in sequence pulls the amps below 1A on the system and shuts off battery power to the inverter. I called SS and they said that the two rack batteries where likely discharged. We are off grid and have very little contestant load to the inverter usually reads around 5% so I question how 2 5kw batteries would drain in 3 days. Any thoughts?

From my quick Google search, your inverter uses about 70 watts just to be on. That alone is 5kWh in 3 days, plus your normal loads I'm guessing used the remainder.

Wait, why do you say 2 batteries drain in 3 days? You've got 3 and should just leave them on.

Also, only one of your batteries has a display and no comms to the other 2. You can't just look at the one battery with a display and assume the other 2 are doing the exact same thing.

 

[Zapper77]

You are measuring the wrong thing.

What system shut off? We assume when you say "System" you are referring to your inverter. Is that accurate?

Do you have a native language thats not english? Are you using a translation app?

 

[Zapper77]

There was no noted alarm from batteries or inverter. Batteries where 100% a week ago. Snow was cleared and amperage from panel array was up to 2.4 amps in fading light. What the issue is in the battery system where bringing them all online in sequence pulls the amps below 1A on the system and shuts off battery power to the inverter. I called SS and they said that the two rack batteries where likely discharged. We are off grid and have very little contestant load to the inverter usually reads around 5% so I question how 2 5kw batteries would drain in 3 days. Any thoughts?

Completely shut down your system and restart from scratch. turn off all breakers and disconnects. I recommend that you read and follow the invter and battery user manuals.

with the Inverter off
Turn on all battery breakers and battery disconnects. (Assuming the batteries are equally charged)
Next turn on the inverter.

What's the status of your inverter did it turn on and start supplying power?

Are you using battery communication?

 

[AndrewG]

Battery, you've only got a picture and current from one battery. Not the entire stack. When you turned on the second battery, the current likely went into that battery, not the first.

You need to measure the voltage and make sure they are close before switching on more batteries.


From my quick Google search, your inverter uses about 70 watts just to be on. That alone is 5kWh in 3 days, plus your normal loads I'm guessing used the remainder.

Wait, why do you say 2 batteries drain in 3 days? You've got 3 and should just leave them on.

Also, only one of your batteries has a display and no comms to the other 2. You can't just look at the one battery with a display and assume the other 2 are doing the exact same thing.

Battery, you've only got a picture and current from one battery. Not the entire stack. When you turned on the second battery, the current likely went into that battery, not the first.

You need to measure the voltage and make sure they are close before switching on more batteries.


From my quick Google search, your inverter uses about 70 watts just to be on. That alone is 5kWh in 3 days, plus your normal loads I'm guessing used the remainder.

Wait, why do you say 2 batteries drain in 3 days? You've got 3 and should just leave them on.

Also, only one of your batteries has a display and no comms to the other 2. You can't just look at the one battery with a display and assume the other 2 are doing the exact same thing.

The second image of amperage reading was 30 seconds after the 2nd battery was turned on. Voltage for all batteries was at 52.4v, checked w/ a multimeter.

So, are you saying the 3 eg4 batteries wired in parallel do not act and not seen as a whole energy source by the inverter? I haven’t seen information that each battery has to be daisy chained with a comm cable and then connected to the inverter. Is this required? My understanding was the lead BMS communicates with the inverter to send the general battery system information for Voltage/amps/shorts/etc, it also monitors the voltage/amps/temp of cells etc for each individual battery. This discreet information temp/cells charge amt etc is not accessible from one battery to the next. That communication would have to be with some kind of battery monitoring software.

One would think that if a system is functioning fine prior with no heat/freezing/short events, one wouldn’t think something internal is happening with one or both of the rack batteries that are only 1.75 years old located in the house. This tack seems a bit contrary to what the folks at SS (Signature Solar) suggest.

All the voltage readings were within .1v. So in terms of what may be happening, does something come to mid?

The direction from SS support was to independently charge the 2 rack batteries to within .2 volts of each other and re-assemble the battery array. The question I have now is; if the system works without a problem with the equalized batteries, what stops this unequal charging event with the current system configuration from happening again? Any idea?

Thank you,
Andrew

 

[Zapper77]

All the voltage readings were within .1v. So in terms of what may be happening, does something come to mid?

Voltage at 50% SOC is no way to measure capacity.

 

[AndrewG]

Completely shut down your system and restart from scratch. turn off all breakers and disconnects. I recommend that you read and follow the inter and battery user manuals.

with the Inverter off
Turn on all battery breakers and battery disconnects. (Assuming the batteries are equally charged)
Next turn on the inverter.

What's the status of your inverter did it turn on and start supplying power?

Are you using battery communication?

I will respond once I have been able to charge the batteries to a relatively equal charge. The LL EG4 is being charged by the inverter individually, I disconnected the 2 rack eg4’s and will charge independently with with a 48v charger. This will take hours for sure…

 

[AndrewG]

Voltage at 50% SOC is no way to measure capacity.

What is?

 

[Partimewages]

Voltage is a very poor indicator of SOC for Lifepo4 battery cells. The charge curve is very flat.

 

[Zapper77]

What is?

A shunt at best, worst the calibrated BMS. Do you have the communication cable so you can read the bms data?