Growatt SPF 3000TL LVM-24P - won't turn on

Just John

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Aug 15, 2020
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So I'm back up North and have topped up the LiFePO4 power wall to about 25 volts with the charger that Rykelo used from Amazon. It worked just fine getting my powerwall up a volt and a bit before showing charged. It still won't turn on the Growatt so I did some more exploration. Sure enough I'm getting plenty of volts on the input side of the BMS but only 7-8 volts on the output side. I've unplugged the BMS for 1 minute to let it reset (suggestion from Big Battery back when they were talking to me). Still low voltage on the output side when connected to the Growatt. Anyhow, just wanted to update folks and will move forward with how to test a BMS. I've attached a visual of the meter connected to the input side of the BMS and output side.. cheers all.View attachment 66555View attachment 66556
It certainly appears that the BMS either has a problem or is turned off for some reason.
 

iamrich

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Dec 17, 2020
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Elgin, Texas
What is the voltage at the Anderson connector? It sounds like you have a bad BMS and assuming you are past sending it back I think I would remove/bypass the BMS and just hook right into the pack. As long as you don't push the battery in either direction (below 24v or above 27v) I don't think you will have a run away cell issue.

Maybe big battery will send you a replacement BMS?
 

ger164

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Jul 12, 2021
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What is the voltage at the Anderson connector? It sounds like you have a bad BMS and assuming you are past sending it back I think I would remove/bypass the BMS and just hook right into the pack. As long as you don't push the battery in either direction (below 24v or above 27v) I don't think you will have a run away cell issue.

Maybe big battery will send you a replacement BMS?
THANKS.. I've just sent them, Big Battery another email explaining issue and asking for help... I've also been on another thread in this forum dealing with the exact BMS and battery.. Very interesting and intelligent members, and a lot over my head.. :oops: Will keep plugging away...
 

Just John

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Instead of a battery charger (that like to sense voltage before they try to charge), hook up a cheap power supply and try giving it 28 volts to see if it wakes up the BMS. Some BMS will wake up when you put some charging current through them, but most chargers won't send current if they don't sense high enough voltage.

This would mean through the Anderson connector. The voltage you see is a BMS that is "asleep".
 

ger164

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Jul 12, 2021
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Instead of a battery charger (that like to sense voltage before they try to charge), hook up a cheap power supply and try giving it 28 volts to see if it wakes up the BMS. Some BMS will wake up when you put some charging current through them, but most chargers won't send current if they don't sense high enough voltage.

This would mean through the Anderson connector. The voltage you see is a BMS that is "asleep".
Thank you. I will look into that. Cheers
 

ger164

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Good morning all from Ontario. Just wishing to update my status or more accurately my system status at my cabin in Northern Ontario. I recently returned after finally getting to the problem of my issues with my BigBattery/Growatt system. I've included a few pics in order to help anyone in a similar situation down the road. After having no luck with my recent battery charger and abnormally low output voltage even though the input side showed plenty of voltage I followed others leads from this forum and did a voltage check between the various pins with a volt meter on the plug. In the end I spotted on cell registering .04 volts with all others showing 3.3 or 3.4 volts. So I dove deep into disassembling the case and exposing the 8 cells inside. Sure enough one of the cells clearly was different from the rest and I tried to get a pic of it. It appeared a "meltdown"occured in one of the circular ports. This was a wonderful discovery and so I am now in the process of exploring my options. I was quoted and estimate from BigBattery of between $1000-$1500 for repair if they can even repair it. So I will now explore building a new system or replacing the one damaged cell. BigBattery now has a Canadian distributor near my location (Toronto) but do not do repairs themselves and would have to ship the unit to the west coast in the States (thus the high cost). Anyhow, I'm up to date on my reporting and wishing everyone a great fall/wintertempImagePnZRLk.pngtempImage8nJv9b.pngtempImageIXOtPL.pngtempImage4E0UUM.pngtempImage5AQRih.pngtempImageJPDw7p.png!! cheers ger
 

iamrich

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Elgin, Texas
This was a wonderful discovery and so I am now in the process of exploring my options. I was quoted and estimate from BigBattery of between $1000-$1500 for repair if they can even repair it.
You can build a much better battery under $1000 with brand new cells, so repair is definitely not recommended unless it is under warranty. The unit you have is good to about 3kwh on a good day, so maybe 125ah at 26.7v. I have two of those packs and am very happy with them, but even I have moved on to buy new cells.

It might be possible to remove the bad cell, but you will not likely find a replacement as each cell has posts on both ends. I am really surprised that Big Battery is not offering a replacement as this is very obviously a DOA type failure. It is not shocking to see bad cells in these used packs, but that cell is dead and the unit should be replaced for free in my opinion.
 

ger164

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You can build a much better battery under $1000 with brand new cells, so repair is definitely not recommended unless it is under warranty. The unit you have is good to about 3kwh on a good day, so maybe 125ah at 26.7v. I have two of those packs and am very happy with them, but even I have moved on to buy new cells.

It might be possible to remove the bad cell, but you will not likely find a replacement as each cell has posts on both ends. I am really surprised that Big Battery is not offering a replacement as this is very obviously a DOA type failure. It is not shocking to see bad cells in these used packs, but that cell is dead and the unit should be replaced for free in my opinion.
thanks iamrich... I like your thinking better than theirs. One learns a lot about relationships when things don't go necessarily well. I would have hoped they would have stepped up here. Moving on - I have the winter to play with learning about building and good new cells to buy. I will even try to reuse the cabinet on wheels to house them as this was a nice look up at the cabin. Have a great day!!
 

iamrich

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Location
Elgin, Texas
Just out of curiosity, have you tried to charge the battery directly (without the BMS and case)? Might be a long shot, but I wonder if the bms is just crap and not charging that cell. I have seen pictures of that white goo stuff on these packs before, but I am not sure that means that cell is beyond hope. If you could somehow get 3.3v of charging on that cell, it would be perfect, but if you can hit the whole pack with 26.7v or so on the main terminals and just see if the cell rises at all. It will take a while to get the other cells up to 3.65max, so you will have time to measure.

Here are some resources on taking the pack apart:

 

ger164

Solar Enthusiast
Joined
Jul 12, 2021
Messages
26
Just out of curiosity, have you tried to charge the battery directly (without the BMS and case)? Might be a long shot, but I wonder if the bms is just crap and not charging that cell. I have seen pictures of that white goo stuff on these packs before, but I am not sure that means that cell is beyond hope. If you could somehow get 3.3v of charging on that cell, it would be perfect, but if you can hit the whole pack with 26.7v or so on the main terminals and just see if the cell rises at all. It will take a while to get the other cells up to 3.65max, so you will have time to measure.

Here are some resources on taking the pack apart:

more wonderful advise iamrich... This will add make the process much easier... I will give the battery a charge without the BMS as well.. Will keep you posted on how this all goes.. cheers
 
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