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Victron Multiplus 3000 and EG4 Lifepower Battery Compatibility Issues?

SoCalKevin

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Apr 10, 2022
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Hey All

I have a Victron Multiplus 3000 inverter in my Off Grid Camper that i use to power everything, Induction Stove, Hot Water Heater, Microwave, and a Houghton Bel Air Air Conditioner.

I have used this for approximately 2 years with a single Lifeblue 300ah battery without issue.

I just upgraded to (2) EG4 Lifepower 400ah (12v) server rack batteries, wire in parallel. All wired with 4/0 cable.

All appliances work fine with the new setup other than the Air Conditioner.

The Air Conditioner draws about 42amps when the compressor kicks on. This has not been an issue with the lifeblue battery for the past 2 years.

With the EG4s, it is tripping the "low voltage" alert on the Multiplus as soon as the compressor kicks on momentarily, but the batteries are fully charged.

I spent over an hour on the phone with Signature Solar going over the BMS software, but the password they had for the software doesnt work with mine.

They ended up telling me to contact Victron, but i am positive its an EG4 BMS issue

Any know compatibility issues with this setup and possible fixes?

Thanks
 
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The AC draws about 42amps when the compressor kicks on.
AC = alternating current
A/C = air conditioner

Is the 42A from the A/C at 120VAC or 48VDC? In other words, is that a 5000W surge at the inverter or a 2200W surge at the batteries?

Verify all connections are tightened properly. A poor connection can cause a big voltage drop.

Make sure your parallel battery connections are being done correctly. Make sure your system isn't connected to just one of the two batteries.
 
They ended up telling me to contact Victron, but i am positive its an EG4 BMS issue
What makes you positive?
How are the batteries paralleled?
Please post pictures of the core of your system.
 
AC = alternating current
A/C = air conditioner

Is the 42A from the A/C at 120VAC or 48VDC? In other words, is that a 5000W surge at the inverter or a 2200W surge at the batteries?

Verify all connections are tightened properly. A poor connection can cause a big voltage drop.

Make sure your parallel battery connections are being done correctly. Make sure your system isn't connected to just one of the two batteries.

Thank you. Edited post.

Yes, 42 amps at 120vac for a very brief second so yes, about a 5000 watt surge, which from what i've read the multiplus is rated for up to 6000

Triple checked all connections are well done, and secure and cabling/wiring is even bigger than needed.
 
What makes you positive?
How are the batteries paralleled?
Please post pictures of the core of your system.

I am positive, because i have tested this all with 2 other batteries, no issues.

Also tried connecting each EG4 up by itself with same result

Will post pic soon
 
I am positive, because i have tested this all with 2 other batteries, no issues.
Could still be some other thing within the battery including the cells.
Not likely but possible.
If you were to bypass the bms would that would be more convincing.
 
Yes, 42 amps at 120vac for a very brief second so yes, about a 5000 watt surge, which from what i've read the multiplus is rated for up to 6000
5000W from the inverter will be about 5500W from the batteries. At 52V that would be 106A pulled from the batteries. With 2 in parallel that should only be 53A per battery. The BMS on the EG4 should handle 53A without issue, especially for only a brief surge.

Do you still have the old battery? If you leave everything else exactly as-is, can you connect the two 4/0AWG battery leads to the old battery instead of the 2 EG4s? Does everything now work correctly? If so, then there is something wrong with the EG4 setup. If not, then it's not the EG4s.
 
Do you still have the old battery? If you leave everything else exactly as-is, can you connect the two 4/0AWG battery leads to the old battery instead of the 2 EG4s? Does everything now work correctly? If so, then there is something wrong with the EG4 setup. If not, then it's not the EG4s.

Thats actually exactly what i did and everything worked correctly.

Then i tried each EG4 by itself, kicked off the inverter low voltage alarm and shut it down.

Then i tried the EG4s in parallel, kicked off the inverter low voltage alarm and shut it down.

All other appliances work though. Even put my coffee maker and water heater on at the same time for maximum draw. Zero issues.
 
Assuming you have a voltmeter, what voltage do you read for each EG4 battery?

What voltage do you read across both batteries in parallel?

What voltage do you read at the inverter battery terminals?

Do the above with no loads.
 
Assuming you have a voltmeter, what voltage do you read for each EG4 battery?

What voltage do you read across both batteries in parallel?

What voltage do you read at the inverter battery terminals?

Do the above with no loads.

Yes, just checked all of those and they are at 13.5
 
So no voltage drop between the batteries and inverter. That's good.

I'm out of ideas. Hopefully you can get this worked out with Signature Solar.
 
Good luck @SoCalKevin . I had an issue with signature solar and their 48v eg4 lifepower batteries not starting my inverter. 3 other brands/chemistries of batteries worked perfectly, just not the eg4's. It took signature months to get me taken care of and they never were able to figure out what the problem was. I found their customer service and tech support to be a joke most of the time. So like i said, good luck. You'll need it!

Are you able to take a voltage reading while the a/c is being turned on? Knowing how low the batteries voltage is dipping may help you to make a change to your low voltage cut off threshold with your victron.
 
Good luck @SoCalKevin . I had an issue with signature solar and their 48v eg4 lifepower batteries not starting my inverter. 3 other brands/chemistries of batteries worked perfectly, just not the eg4's. It took signature months to get me taken care of and they never were able to figure out what the problem was. I found their customer service and tech support to be a joke most of the time. So like i said, good luck. You'll need it!

Are you able to take a voltage reading while the a/c is being turned on? Knowing how low the batteries voltage is dipping may help you to make a change to your low voltage cut off threshold with your victron.

Thanks @Koldsimer thats a bummer to hear! :(

To be fair, its only been a couple days, and so far their service has been great even though the issue isnt fixed yet.

As for the voltage settings in the Victron, i went in and even tried setting them below 10v and still no luck. Bummer
 
5000W from the inverter will be about 5500W from the batteries. At 52V that would be 106A pulled from the batteries. With 2 in parallel that should only be 53A per battery. The BMS on the EG4 should handle 53A without issue, especially for only a brief surge.

Do you still have the old battery? If you leave everything else exactly as-is, can you connect the two 4/0AWG battery leads to the old battery instead of the 2 EG4s? Does everything now work correctly? If so, then there is something wrong with the EG4 setup. If not, then it's not the EG4s.
But, he's got the 12 volt version, not the 48 volt version.

So he's pulling something like 450+ amps surge from packs that are rated at 200 peak amps each?

With some luck that might work, but if one pack has slightly lower internal resistance, that one is going to trip for over current, then the load all falls to the second pack and it obviously trips over current.


OP, your old batteries probably don't have a protection circuit (BMS) built in, so yes they do fine.
In my opinion you didn't do enough research and bought batteries that need to run at 120% or more of their rated current to work. Or you need a third.
But, Richard from signature is right, try full charging them a couple times. You might get that extra bit you need.
 
But, he's got the 12 volt version, not the 48 volt version.

So he's pulling something like 450+ amps surge from packs that are rated at 200 peak amps each?

With some luck that might work, but if one pack has slightly lower internal resistance, that one is going to trip for over current, then the load all falls to the second pack and it obviously trips over current.


OP, your old batteries probably don't have a protection circuit (BMS) built in, so yes they do fine.
In my opinion you didn't do enough research and bought batteries that need to run at 120% or more of their rated current to work. Or you need a third.
But, Richard from signature is right, try full charging them a couple times. You might get that extra bit you need.
This would be true if he was pulling max load and then the AC kicked in - so a possibility but very unlikely. It's not something I'm ruling out but we are also troubleshooting in a few other ways.

Edit: Just realized I misread the reply you put. This actually might be the issue - if it's exceeding the amps for peak pulling + the amps to run the inverter, that might cause an OC error for discharge - which then results in a low voltage error on his inverter (from the bms limiting output voltage). Only real way to test would be to have a 3rd battery but I don't think he has the space. Will continue working with SoCal on this one.
 
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