Growatt SPF 12000T DVM-MPV MPPT Failure

Yesterday I had the MPPT board fail catastrophically in my Growatt SPF 12000T DVM-MPV.

I pulled into the driveway and opened the garage only to be met by a wall of smoke. I hit the DC and AC cutoffs outside and flipped the cut-off switch on each of my 3 batteries. I initially thought it was the batteries, but the acrid smell was more reminiscent of burnt resistor and circuit board. After confirming that each battery was in good shape, I turned to the inverter and saw soot on the lower right-hand side ventilation holes. I removed the front cover and, well...the pictures say it all.

The inverter has been up and running since early June 2022 with nothing major to be noted, just the "standard" quirks that the unit has.

I have 14x Mission Solar MSE320SR8T panels (Imp = 9.351A, Vmp = 34.22V) connected to the inverter in 2 arrays. (Array 1 = 5s2p, and Array 2 = 4s)

The last system stats recorded in SolarAssistant were as follows:

• Power recorded coming from the panels totaled 755W
  • 127v @ 3.61A for MPPT 1
  • 56.2v @ 6A for MPPT 2
• Inverter temperature was 24.7C
• Battery voltage 52.7v (LiFePO4, 840AH)

To add insult to injury, yesterday was a beautifully sunny day but I was only able to capture ~1.1kW of it.

and now you have to wait for a replacement / repair parts or units. this is why a AIO is not the way to go. multiple components make for easier maintenance.

I have 4 SCC. they are all running at about 35%. one burns up I put the extra panels on one of the other units and continue on until replacement parts arrive.

Two inverters, either one can run the entire house. one goes south, put one on full duty until parts/replacement arrives. (I now keep spare boards, so that would be like 5 minutes to swap out).

BMS? 4 of them only two running, guess what, swap out in five minutes. each of the individual items are less that one AIO unit. my system overall is more expensive not counting spares, but even counting spares its better than an AIO unit.

My opinion, you mileage may vary.

Ken

Ouch!!

Is it possible that your 5S string over-voltaged the MPPT input?

Check the Voc of your panels and the maximum DC input voltage of the MPPT.

How cold has it been getting (Voc rises as temperature falls)?

Or.....his BMS suddenly disconnected due to cell overvoltage protection kicked in which resulted arcing at the MPPT board?
Does the BMS report any High Voltage Disconnect event for one of the cell in the battery pack?

Daddy Tanuki said:

and now you have to wait for a replacement / repair parts or units. this is why a AIO is not the way to go. multiple components make for easier maintenance.

I have 4 SCC. they are all running at about 35%. one burns up I put the extra panels on one of the other units and continue on until replacement parts arrive.

Two inverters, either one can run the entire house. one goes south, put one on full duty until parts/replacement arrives. (I now keep spare boards, so that would be like 5 minutes to swap out).

BMS? 4 of them only two running, guess what, swap out in five minutes. each of the individual items are less that one AIO unit. my system overall is more expensive not counting spares, but even counting spares its better than an AIO unit.

My opinion, you mileage may vary.
Ken

Click to expand...

And how was this was helpful? There is nothing wrong with AIO units. So you have spares…if the OP has a spare mppt board, he can plug it in and he’s back in business.

Perhaps thread starter might want to contact Amos at Growatt?

I mean......... a good company normally would like to request the damaged item back for analysis for product engineering improvement.

Brett V said:

And how was this was helpful? There is nothing wrong with AIO units. So you have spares…if the OP has a spare mppt board, he can plug it in and he’s back in business.

Click to expand...

everybody has their own level of redundancy. mine is no wait fix it in five minutes.

if you have two or three of the AIO's you can do that, but in all honesty the ability to change out a specific portion of the system is the final word.

so you have three AIO's one online and two as backup. one fries its solar input, one fires its inverter, and one just shits the bed because its cheap Chinese crap.

you are down more than the cost of one top tier inverter, spare boards, a separate top tier SCC.

garbage in, garbage out your decision. I make my choices on reliability not what is cheapest and paraded around the forum so a few folks make get rich of off it.

Daddy Tanuki said:

and now you have to wait for a replacement / repair parts or units. this is why a AIO is not the way to go. multiple components make for easier maintenance.

I have 4 SCC. they are all running at about 35%. one burns up I put the extra panels on one of the other units and continue on until replacement parts arrive.

Two inverters, either one can run the entire house. one goes south, put one on full duty until parts/replacement arrives. (I now keep spare boards, so that would be like 5 minutes to swap out).

BMS? 4 of them only two running, guess what, swap out in five minutes. each of the individual items are less that one AIO unit. my system overall is more expensive not counting spares, but even counting spares its better than an AIO unit.

My opinion, you mileage may vary.

Ken

Click to expand...

Not within my budget to do that from the initial setup. I can currently use a duty free allowance for imports for solar hardware. I would need to pay a 25.25% duty on the cost of a dedicated inverter, plus shipping. I was able to bring in the AIO inverter and my battery cells and not have to pay duty on them. If the inverter didn't specifically need batteries to run, I would have had to pay duty on the battery cells that I ordered at 33.5%. This would have increased the battery cell cost by around $3000, bringing my total setup cost over $20k.

crossy said:

Ouch!!

Is it possible that your 5S string over-voltaged the MPPT input?

Check the Voc of your panels and the maximum DC input voltage of the MPPT.

How cold has it been getting (Voc rises as temperature falls)?

Click to expand...

I can't see the 5s string causing an above voltage limit issue. The panels Voc is 40.80V. The 5s string would bring the total to 204V. The inverter specs list the MPPT as having a maximum PV Array Voc of 250VDC.

Temperatures have been falling between 14C to 19C overnight, with daytime temperatures being a few degrees higher.

AshleyL said:

Or.....his BMS suddenly disconnected due to cell overvoltage protection kicked in which resulted arcing at the MPPT board?
Does the BMS report any High Voltage Disconnect event for one of the cell in the battery pack?

Click to expand...

The batteries were just starting to charge from being dormant overnight. I have SolarAssistant set to switch to grid when the battery array reaches 65%. It switches from grid to solar+battery after the battery reaches 70%. (This gives me reserve to use during unexpected outages.) The battery array was sitting at 68% according to the 1000A Victron SmartShunt. The battery array was only taking in 15.3A. With the 3x 280Ah @ 48v batteries, that would put me around 0.018C charge rate accross the 3 batteries. I bulk charge the cells to 3.5125v/cell for a pack charge of 56.2V. The cell spread at that voltage is between 10mV to 30mV depending on the pack.

There are no recently logged events in any of the 3 BMS units. (Last event log was from testing in August.)

Brett V said:

And how was this was helpful? There is nothing wrong with AIO units. So you have spares…if the OP has a spare mppt board, he can plug it in and he’s back in business.

Click to expand...

I don't have a spare on me, unfortunately. As soon as I have replacements, they're being installed immediately. Power has gotten stupidly expensive here over the past 2 months.

• First Block (Up to 250kWh) = $0.38762/kWh
• Second Block (250 - 700kWh) = $0.49422/kWh
• Tail Block (700kWh+) = $0.63092/kWh

AshleyL said:

Perhaps thread starter might want to contact Amos at Growatt?

I mean......... a good company normally would like to request the damaged item back for analysis for product engineering improvement.

Click to expand...

I've sent an email to an address listed on Growatt's site, but havn't heard anything back yet. I've sourced replacement parts for a few hundred $ before shipping, but wouldn't mind speaking with Amos at Growatt before pulling the trigger. Are you able to point me in Amos' direction?

Gannam said:

I've sent an email to an address listed on Growatt's site, but havn't heard anything back yet. I've sourced replacement parts for a few hundred $ before shipping, but wouldn't mind speaking with Amos at Growatt before pulling the trigger. Are you able to point me in Amos' direction?

Click to expand...

xing.yang@growatt.com

Don't bother with the official growatt global email, they take forever to reply. It took them 3 weeks (21days) to assign a technician to "assist" me.
If you want best email based support, send email to growatt netherland branch instead.

Daddy Tanuki said:

everybody has their own level of redundancy. mine is no wait fix it in five minutes.

if you have two or three of the AIO's you can do that, but in all honesty the ability to change out a specific portion of the system is the final word.

so you have three AIO's one online and two as backup. one fries its solar input, one fires its inverter, and one just shits the bed because its cheap Chinese crap.

you are down more than the cost of one top tier inverter, spare boards, a separate top tier SCC.

garbage in, garbage out your decision. I make my choices on reliability not what is cheapest and paraded around the forum so a few folks make get rich of off it.

Click to expand...

Individual boards in the Growatt are able to be replaced with a minimum amount of effort.

Gannam said:

• First Block (Up to 250kWh) = $0.38762/kWh
• Second Block (250 - 700kWh) = $0.49422/kWh
• Tail Block (700kWh+) = $0.63092/kWh

Click to expand...

WOW!

Kornbread said:

WOW!

Click to expand...

Wow indeed. Coupled with the crazy rates is a monthly "facilities fee" of just over $70. This fee drops to around $35 if you backfeed to the utility company. They just dropped their purchase fees from around 22c/kWh to around 11c/kWh. There was a public response that resulted in them upping the buyback to around 19c/kWh. It's awesome to sell them power for 11c/kWh, only to have to buy it back for an absolute base cost of $0.38762/kWh.

I eventually aim to up my solar array to a total as close to 12kWh, or greater, as I can. When I can add more panels, I'm thinking of using an EG4 18kW PV AIO inverter as it can do everything that the Growatt can, plus can be put in parallel and can backfeed. I'll either use the Growatt as a backup/spare or to power garage+workshop+apartment. During the summer, I'll have a surplus of power that I'll be able to bank a credit on with the utility, and I'll have the credits to use over the winter during multiple days of low production due to weather. With that being said, who knows what'll happen/what'll be available when I'm able to file paperwork for the permits needed to install more panels. (I'll likely not be able to proceed for another year or two. The solar budget has been gutted as the majority of its funds have been redirected as we're expecting our 3rd daughter in March.)

AshleyL said:

xing.yang@growatt.com

Don't bother with the official growatt global email, they take forever to reply. It took them 3 weeks (21days) to assign a technician to "assist" me.
If you want best email based support, send email to growatt netherland branch instead.

Click to expand...

Thank you for the contact info. I've sent an email with a summary of what's occurred. While I'm waiting for a reply to see if they can assist, I've ordered the two needed boards from watts247. I want to minimize downtime, as the system knocks off a significant chunk from the power bill, especially during sunny months. (December resulted in ~$141 saved, and July was ~$349 saved.)

The boards are expected to arrive on the 29th, but I still need to source the fans. Once everything arrives, I'll install and test right away.

Congrats on the family addition. IMO, kids are the most important investment of our lives.

Ian at watts247 seems to be a very helpful dude, he also has a new do-it-all AIO soon to be released that might pique your interest. Since you are in Bermuda, is Deye a possibility? IIRC, they are the oem for SolArk, and SolArk has a solid reputation for dependability.

Brett V said:

Individual boards in the Growatt are able to be replaced with a minimum amount of effort.

Click to expand...

for how many years? i can still get replacement boards for an inverter that was first sold in 2004... can you do that with any of the Chinese products?

Kornbread said:

Congrats on the family addition. IMO, kids are the most important investment of our lives.

Ian at watts247 seems to be a very helpful dude, he also has a new do-it-all AIO soon to be released that might pique your interest. Since you are in Bermuda, is Deye a possibility? IIRC, they are the oem for SolArk, and SolArk has a solid reputation for dependability.

Click to expand...

I haven't looked into the Deye inverters. Most suppliers locally only install/have on hand AC coupled inverters with no battery support. As the local utility here has been messing around with buy-back rates, I'm prioritizing off-grid style inverters. With that being said, I would like my next inverter to have the capability to dump onto the grid as as it would lower my monthly facility charge from ~$70 to ~$35.

Daddy Tanuki said:

for how many years? i can still get replacement boards for an inverter that was first sold in 2004... can you do that with any of the Chinese products?

Click to expand...

For your 4x Tri-Star MPPT60 charge controllers at almost $700 each, and your Magnum 4448 at ~$2000 each, I'd hope they would give you a foot massage while replacing the boards themselves on-site. I would need 3 of the Magnum 4448 inverters in parallel (~13.2kW constant), and 3 Tri-Star MPPT60 charge controllers after re-configuring my array, needing more wiring as well as channelling out concrete and stone walls to install larger conduit. (I would need to split my 5s2p array into 2 separate arrays. My 5s2p array is angled at about 30°, while my 4s array is angled at about 5°. This cannot be changed as it is roof-mounted as per government regulations.)

I would need to spend $8,100 for the inverter and MPPT controllers, before shipping + wharfarage fees on everything with additional ~$1,500 duty on the inverters. Ignoring the shipping costs, I would be spending an additional ~$5,300 on the inverters and MPPT charge controllers alone. I find the argument akin to comparing a Ford Focus to a Rolls-Royce and a moot point concerning my issue, but thank you for your input.

I received my replacement boards from Ian @ watts247, ordered on the 20th and received on the 25th. It looks like the charge controller board differs from the original and I have yet to receive confirmation from Growatt as to whether this is correct or not. As per Ian's instructions, I have not installed the new board, and have installed the old controller board for testing. (Prior to installation, I cleaned it with isopropyl and a soft brush, allowing it 24 hours to completely dry in a humidity controlled envirionment, which is standard proceedure for when I repair circuit boards.) When everything's installed the charge controller board emits a continuous tone, and the firmware is recognized as "000 000." (The inverter's firmware is correctly identified, it is just the MPPT side that's erroring.)

Ian's contact at Growatt wrote early this morning and reported that the warranty had expired and that I would need to purchase replacement boards, which I've already done. My issue with this is that they initiated the warrany as Ian's stock purchase date and not my puchase, delivery, or install date. If going by Growatt's warranty commencement as being no more than 6 months after the delivery date to the consumer, it would be out of warranty by less than 1 month, and if going by the installation date, I would have just shy of an additional 5 months of warranty left.

I belive that they provided Ian with the incorrect controller board, which was not noticed until after it was shipped and I compared the boards prior to installation. My hope is that Kevin @ Growatt replies saying that the new board is correct and the additional pins are for programming, but I highly doubt that's the case.

Ultimately, this is a nuissance which I believe would be sorted if they provided the correct controller board. I find Growatt's warranty coverage/support to be laughable, although I wasn't expecting much different.

Ian has been helpful with support during the selection and purchase of the hardware, providing access to firmware updates regarding a known fan-fault error with the unit, and obtaining replacement parts afterwards (minus the controller board in question addressed above). I would not hesitate to purchase from him again. (He has replied to my emails quickly and I've always been able to contact him via phone.)

I will post again once I have an update concerning the controller board. Thankfully the weather for the most part has been crummy here since the failure, so I'm only "missing out" on approximately 20kW of generation total so far. (I have a relative that has an 8.5kW array with whom I compare daily generation with. His average generation is just shy of 2x what I make on a day, give-or-take a few kW/day.)

I believe that board came straight from Ian's inventory as there's little chance a replacement board made it to you that fast from China. Ian has been selling various Growatt boards on eBay for quite some time now trying to offload his inventory.

shopman said:

I believe that board came straight from Ian's inventory as there's little chance a replacement board made it to you that fast from China. Ian has been selling various Growatt boards on eBay for quite some time now trying to offload his inventory.

Click to expand...

I have no doubt that it was in his current inventory with how quickly it arrived here. It's listed as a replacement board for the Growatt SPF 12000T DVM-MPV, "GROWATT DVM 12000T MPV MPPT Control Board (Size of a credit card) SKTV03.0003200" on wats247. I emailed him to confirm that the boards that I had selected were correct before "pulling the trigger" on the order after relaying specifics concerning my system failure.

I'm waiting to hear back from Growatt support as to whether or not the board is actually correct for my system, and if not, what model unit the board is actually for.

My order of 2x 60mm Noctua fans have arrived on-island, which I'll be using to replace both fans for the MPPT board. (One is still operational, and one was completely melted. I suspect that the original fan that still seems to be operational will have a bearing failure prematurely due to the heat exposure.) I've used 3 layers of kapton tape to isolate the fan bracket from the MPPT board as the original plastic insulator was 1/2 melted. While I have the unit open again, I'll re-verify the integrity of the signal/data wire harnesses that pass over the MPPT board. If needed, I'll remake the wiring harnesses.

Wow she blowed up good.
Is there any possibility that the inverter was subject to any kind of dampness or at least rather high humidity?

Quattrohead said:

Wow she blowed up good.
Is there any possibility that the inverter was subject to any kind of dampness or at least rather high humidity?

Click to expand...

Nothing higher than what's normal here. It's located in the back of my garage so there's no chance that there was any liquid intrusion. During the winter the garage's internal temperature is usually a few degrees warmer than the outside temperature, and during the summer a few degrees cooler than the outside temperature. During the installation I taped screens externally over the large fan grills on top and one on the bottom to prevent large insects from wandering through it. (There is no dust buildup over the screens. I check the unit and batteries whenever I put the car in the garage, which is usually several times a day as my business workshop is at home.) I've attached a screenshot of the day from my weather station which is located in my backyard.

I have confirmation from Sim at Growatt that the replacement MPPT control board that I ordered is incorrect. (Amos assigned the case to Simphiwe, who goes by Sim.) I will be shipping it back to Ian and am looking to get a replacement from Growatt directly.

The connection that essentially blew off the board was the positive battery connection. There is a 2-wire lead from the primary battery connection to the MPPT power board. (One pair for the positive and one pair for the negative.) Closer examination of SolarAssistant's logs show that the power flow went from ~755W into the batteries to an ouput surge of ~3.1kW and then a spike to ~8.5kW before power was cut. (8.5kW is ~60A from each of the 3 batteries. This is well within the discharge spec for the cells so the BMS's weren't tripped and each battery has a 250A fuse, which of course didn't trip either.) The discharge occurred for a ~1minute period. The replacement MPPT power board, and the remaining good boards in the inverter, all have a conformal coating, so I'm leaning towards an internal board fault being the cause of the failure at this point. The failed board having the problem section blown to bits, and not having a schematic, makes a diagnosis difficult.

I will update as I have more information.

I've run in to a dilemma. I went to return the incorrect MPPT control board to watts247 and FedEx wants $102 to send the board out...the board cost $105. I'm looking into other couriers on Monday, but I suspect that the cost will be similar. My brother flies out to the US next month, but that's past the 30 day return policy. (I'll email Ian asking if there can be an extension due to the circumstances.)

I did try reflashing the firmware to see if it would detect the board correctly, but no such luck. The inverter shows the firmware version as '511 220' but the MPPT firmware is reporting as '000 000.'

I am looking into alternate options as I wait for Growatt to assist with ordering the correct MPPT control board. (I expect that this could take months with the way that things have been going.) I've essentially narrowed it down to two options that can be put into place without having to pull new wiring from the roof-mount panels to the MPPT charge controller(s). They are 1x Growatt or 2x Victron MPPT charge controllers:

• Growatt
  • SC48120-MPV
    • There is a possibility that I might be able to have this recognized in SolarAssistant, but I'm not counting on it.
    • I don't have to alter my strings at all as this is essentially the same as what's in the SPF 12000T DVM-MPV.
    • Lowest cost option at ~$400 before shipping.

• Victron (For all Victron calculations I used my panel's specs and went below the minimum record temperature here as a buffer.)
  • SmartSolar MPPT 250/70 Tr
    • The 5s2p string can connect to this with no modifications.
    • The PV power ratio is reported as 80% (undersized) using Victron's MPPT calculator.
    • Cost is ~$480 before shipping.
  • SmartSolar MPPT 150/35
    • The 4s1p string will have to be converted to 2s2p. This can be done on the roof with two branch connectors. (I have an additional fuse that I will install to the additional string.)
    • The PV power ratio is reported as 64% (undersized) using Victron's MPPT calculator.
    • Cost is ~$183 before shipping.

Points I've been using to weigh options:

• I have a once-bitten-twice-shy with Growatt's MPPT boards. (I'm VERY happy that I have everything installed in the detached garage. I had this as a requirement when designing the setup and would recommend others install their equipment somewhere outside of their houses as well if at all possible.)
• The Victron equipment is slightly more efficient, but there's no way that I'd be able to interface it with SolarAssistant at this time. I would have to use Venus on a Rasberry Pi and have it and SolarAssistant report to HomeAssistant for a unified interface.
• When I eventually get the part(s) needed to repair the 12kW inverter, I can either put the arrays back on it or continue to use the stand-alone MPPT controllers. The unused controllers can either be used when I expand my array, or saved as backup units.
• I can get two of the SmartSolar 250/70 Tr units and not have to alter the smaller string at all either. This is of course a much more expensive option, but may potentially be more flexible in the future if used in the larger planned array. With that being said, I would likely keep them in place once setup.
• I will have to pull the funds from boat upgrades, which really bites. (I'll have to apologize to my wife and kids for not replacing the marine head this summer.)

Any input on the above or options that I've not thought of would be appreciated. It's always nice to have another set of eyes on a problem/solution.

I have an older sc48120, 150v pv max. It doesn't have the extra port so it does not talk with the growatt spfxxxk, but Solar Assistant sees the JK bms and reports the correct battery power input, but the other charts are not correct. The newer sc48120 with the extra port is 'supposed' to communicate with the spfxxxt. Communica with Solar Assistant says if the spfxxxt and sc48120 are communicationg, SA will show the correct values.

You can set up the Growatt charge controller in Solar Assistant as an SPF inverter. Solar Assistant will correctly report everything that both MPPT's are generating but that's where it ends. Trying to adjust the controllers settings via Solar Assistant will not work since it's not an inverter. It's strictly a read-only device in this setup. You will need a DB9 serial to USB converter(preferably with the FTDI chip) to make the connection with the supplied Growatt cable. Don't bother with setting up communications between the controller and the AIO. It does work but offers no advantage as you can not make adjustments to the SC48120 through the inverter. I have the SPF8000T DVM MPV AIO and the SC48120 working happily this way under Solar Assistant in open loop. Haven't had any problems with the inverter in two years but I do open it up periodically and blow the dust out of it since it has no filters. Too bad we're on opposite ends of the continent as I would love the chance to examine the failed board in person to see what went wrong. If the inverter portion runs without the MPPT/controller installed I would probably just pick up the external charge controller and run with it until the inverter dies, but I'm not in quite the same situation as you are.

shopman said:

You can set up the Growatt charge controller in Solar Assistant as an SPF inverter.

Click to expand...

Does it connect alongside your inverter on the same instance of SolarAssistant, or did you need to purchase an additional licence and Pi? (I thought you could only have multiple inverters listed if they were the same and configured in parallel, but it's been a bit since I've actually looked over the documentation.)

While trying to make a decision, I've dusted off a no-longer-used Pi2 and have installed VenusOS on it. I should be able to get it to interface with HomeAssistant for a pooling of resources.