The "Meg" Build

[DanielS]

Uh oh. Getting an error F09 from the LV6548. Checked the manual and it says "bus soft start failed" and the fix is to return it to a repair facility...

So far all I've tried is to reset it, and to disconnect battery power and disconnect grid power for 10 min and turn it back on. Still throwing F09.

Hey @Lt.Dan I bumped you in my post on the F09 error I'm having. I know you got this resolved by replacing he main board, but did you ever figure out what actually caused the issues. Working with Ian to troubleshoot, looks like I'll have to replace the board as well, but in the end, I have no idea why this happened and don't want it to happen again. My system has been running great over about a month and a half without issue and Boom, I'm dead in the water.

 

[Lt.Dan]

Hey @Lt.Dan I bumped you in my post on the F09 error I'm having. I know you got this resolved by replacing he main board, but did you ever figure out what actually caused the issues. Working with Ian to troubleshoot, looks like I'll have to replace the board as well, but in the end, I have no idea why this happened and don't want it to happen again. My system has been running great over about a month and a half without issue and Boom, I'm dead in the water.

I did not find out. I sent the bad main board back to Ian for him to have for parts. I'm assuming the board had a meltdown of something, as when mine failed, it was under an extremely heavy load with little air flow and it overheated.

 

[MrM1]

How did you handle AC and DC grounding within the RV

 

[Lt.Dan]

How did you handle AC and DC grounding within the RV

12v DC was grounded to the chassis in the OEM fashion, 48v was isolated to the battery/inverter.

AC was ran with no external grounding. Output of the inverters went to a Breaker panel w/ N-G bond, and then straight to the OEM distribution box in the RV.

 

[Lt.Dan]

Since I pulled the battery out of the Meg for the new home, I just ordered a pre-built from Trophy Battery. Pretty excited!

 

[Lt.Dan]

Got the trophy battery a few days ago, been slow charging it with just a 5a charger whenever I am there. Today it hit HVD at 56.2v because 2 cells ran to 3.65. I used the supplied cable to connect to my laptop, which would not work for some reason? Then I used my other cable that I already had, and it works fine. Weird.

But yeah, they are not great in terms of balance.

For reference, this is my DIY 540ah pack with a few cells that are definitely Grade B if not C. Still way better balanced.



I have let it sit at 56.2v, we're going to see if the balancer actually does anything in 24hrs.

 

[12VoltInstalls]

my DIY 540ah pack with a few cells that are definitely Grade B if not C. Still way better balanced.

Will not that BMS-equipped manufactured battery self-balance itself in a few cycles?
Or maybe I have had too high of an opinion of BMS’s?

 

[Lt.Dan]

Will not that BMS-equipped manufactured battery self-balance itself in a few cycles?
Or maybe I have had too high of an opinion of BMS’s?

To my knowledge, more cycles will drive it out of balance. The longer it sits above 3.4v, the better balanced it will get though.

This BMS is still only 200ma of passive balance current, which is way better than Daly's 20ma, but still lacking IMO. If the cells are well matched, then the 200ma is sufficient though. We'll see once I start actually using it.

 

[FilterGuy]

This BMS is still only 200ma of passive balance current, which is way better than Daly's 20ma, but still lacking IMO. If the cells are well matched, then the 200ma is sufficient though. We'll see once I start actually using it.

200ma is sufficient only if it is allowed to keep balancing after the charge stops. If the BMS is set to balance only during charge, 200ma will not do the job.

Also, the balance should only be turned on at a higher state of charge when the cells are above the knee of the charge curve. Below that the voltage is not an accurate comparison of SOC of the cells and the balancer could actually be making the balance worse.

 

[Sanwizard]

200ma is sufficient only if it is allowed to keep balancing after the charge stops. If the BMS is set to balance only during charge, 200ma will not do the job.

Also, the balance should only be turned on at a higher state of charge when the cells are above the knee of the charge curve. Below that the voltage is not an accurate comparison of SOC of the cells and the balancer could actually be making the balance worse.

Yup, and that is one of the main reasons I like the HELTEC/JBD over the Seplos BMS's. That, and the JBD app is nice. Jblance is making great progress on Github also for monitoring.
Seplos comms is a nightmare, and they force you to buy new hardware for what should be a simple firmware upgrade. They seem to be listening to Andy though on "off grid garage", and are making progress. I have seven of Seplos's BMS's, so I am kinda locked in for now.
BTW, I found the perfect platform for the 280ah Mason enclosures from uline.

1​

EA

H-4819

HEAVY DUTY STEEL DOLLY - 30 X 18"

145.00​

145.00​

30 x18 is the perfect size for that kit. This dolly holds 2000LBS, so perfect for making a stack of them mobile.

 

[Hedges]

Hard plastic wheels will leave a groove in wood floor.

I have some 3-wheel dollies under a couple heavy pieces, and they leave indented grooves all over my bamboo plank floor.
I got a 6-wheel mechanic's creeper with urethane tires, which I mounted under a kitchen cabinet to make moveable island. That rolls without causing damage.

 

[Lt.Dan]

200ma is sufficient only if it is allowed to keep balancing after the charge stops. If the BMS is set to balance only during charge, 200ma will not do the job.

Also, the balance should only be turned on at a higher state of charge when the cells are above the knee of the charge curve. Below that the voltage is not an accurate comparison of SOC of the cells and the balancer could actually be making the balance worse.

Yes the Seplos BMS does balance without charging, and also only enables balancing above 3.4v.


I just checked the battery, and at 56.2v, high is 3.598v and low is 3.463v. Its doing something, just at a snails pace. Im half tempted to open it up and manually balance with a bench top power supply...

 

[Sanwizard]

Hard plastic wheels will leave a groove in wood floor.

I have some 3-wheel dollies under a couple heavy pieces, and they leave indented grooves all over my bamboo plank floor.
I got a 6-wheel mechanic's creeper with urethane tires, which I mounted under a kitchen cabinet to make moveable island. That rolls without causing damage.

The floor will be concrete.

 

[Sanwizard]

The floor will be concrete.

 

[12VoltInstalls]

leave indented grooves all over my bamboo plank floor

impressive in a negative way​

One of the selling points of bamboo is its hardness. While it “tears” easily it is supposed to be very dent resistant.

200ma is sufficient only if it is allowed to keep balancing after the charge stops. If the BMS is set to balance only during charge, 200ma will not do the job.

Also, the balance should only be turned on at a higher state of charge when the cells are above the knee of the charge curve. Below that the voltage is not an accurate comparison of SOC of the cells and the balancer could actually be making the balance worse.

So that’s interesting.
My inquiry is due to the cheapo btrpower 140Ah batteries I bought. I haven’t gotten back to that project (still not installed) but I’m suspicious of their BMS’s ability to balance cells.
So basically you are saying I should independently charge them individually and keep them on the charger for a day or two so they can do the metaphorical equivalent of ‘absorb’ and perhaps balance without pulling a Will and cutting them open. If their BMS is that smart.
In another thread it was recommended to me to purchase a ‘generic’ $90 BMS that I believe was purported to be a JBD clone. I’ll get to that eventually. Of course that makes the btrpower batteries $575 each instead of $390…

 

[FilterGuy]

So basically you are saying I should independently charge them individually and keep them on the charger for a day or two so they can do the metaphorical equivalent of ‘absorb’ and perhaps balance

Unfortunately, it may not be as simple as that. Leaving them on the charger may help, but once the cells are full, the current will go to zero and the BMS will detect that as 'no charging'. If the BMS only does balancing during charge, the balancer does not get enough time to balance out the cells.

I recently ran into this very problem with a 100Ah Bluetooth SOK battery that is out of balance. Since the SOK BMS only balances during charge, the cells would never balance. (I have contacted SOK about this and they kinda acknowledged it is a problem..... hopefully they fix it)

 

[Lt.Dan]

Well, the trophy battery has been through 2 cycles now, and is getting way better into balance. Very pleased to see that actually working.

I was having problems getting the trophy battery to talk to my laptop with Battery Monitor and the cable they provided. I called Dan at Trophy up to chat with him, and when I mentioned I have the same BMS in a DIY Battery (Seplos BMS), he immediately assured me that it is NOT a Seplos BMS. This is surprising because it looks, acts, and works IDENTICALLY to a Seplos. Solar-Assistant's website even says its a Seplos. Dan wouldn't go into further detail about the BMS, but he assures me it is not.

So he sends me the link to his software for monitoring, and it is the exact same Battery Monitor software that Seplos sent me, just with a different logo (and an older version, he gave me 2.1.8, where Seplos gave me 2.1.9). Among other things, he sent me drivers for the cable they provided though, and after installing the drivers, the laptop communicated with the Battery flawlessly. It even communicates exactly the same in the v2.1.9 from Seplos.

Not sure why he would tell me this, unless he was originally getting them from Seplos, and then had them copied in China and is just having them made for himself?

Either way this is a bummer because I wanted to run the Trophy battery and my DIY battery in parallel, with communication to each other and then communicating to Solar-Assistant. Anybody know if this is still possible?

The trophy battery does successfully communicate with Solar-Assistant after updating to the most recent version on Solar-Assistant. Wish I could get both packs on there.

 

[Sanwizard]

Well, the trophy battery has been through 2 cycles now, and is getting way better into balance. Very pleased to see that actually working.

I was having problems getting the trophy battery to talk to my laptop with Battery Monitor and the cable they provided. I called Dan at Trophy up to chat with him, and when I mentioned I have the same BMS in a DIY Battery (Seplos BMS), he immediately assured me that it is NOT a Seplos BMS. This is surprising because it looks, acts, and works IDENTICALLY to a Seplos. Solar-Assistant's website even says its a Seplos. Dan wouldn't go into further detail about the BMS, but he assures me it is not.

So he sends me the link to his software for monitoring, and it is the exact same Battery Monitor software that Seplos sent me, just with a different logo (and an older version, he gave me 2.1.8, where Seplos gave me 2.1.9). Among other things, he sent me drivers for the cable they provided though, and after installing the drivers, the laptop communicated with the Battery flawlessly. It even communicates exactly the same in the v2.1.9 from Seplos.

Not sure why he would tell me this, unless he was originally getting them from Seplos, and then had them copied in China and is just having them made for himself?

Either way this is a bummer because I wanted to run the Trophy battery and my DIY battery in parallel, with communication to each other and then communicating to Solar-Assistant. Anybody know if this is still possible?

The trophy battery does successfully communicate with Solar-Assistant after updating to the most recent version on Solar-Assistant. Wish I could get both packs on there.

Seems like Solar-Assistant is really stepping up their game, and adding support to many different elements! Their software is great asset for monitoring SOC via Victron shunts, multiple inverter variants including Voltronics/ MPP (yay!), and now Seplos BMS's( another yay!)
I am glad they are making the effort, as they will end up as THE standard to beat.

 

[Lt.Dan]

Finally finished the compartment again. I removed 1x of the LV6548's for other plans, the trailer doesn't need both anyways now that we aren't living in it full time. I wired it through the factory transfer switch this time, so we can use shore or inverter power. I also removed the A/C unit as it wont be necessary very much. I just need to patch the hole in the side, and I can reinstall the propane tank again. Made a lot more room for storage too!

The trophy battery fits great, and I used a nice Anderson connector to make it removeable. Very minimal, no extra BS. K.I.S.S.

 

[Lt.Dan]

Trying to get the inverter communicating with the battery, but found no info online, nor did I find anybody who has even done communications from the Trophy Battery to the LV6548. After reaching out to Dan at Trophy, he said that the Pylontech protocol the Trophy battery uses is incompatible with the LV6548.

I bought the battery because in the manual it states it can communicate with Deye (Sol Ark) and Voltronic (MPP) only to find out it does neither of them. I asked Dan to please update his Manual, because that's pretty upsetting.

Now I'm trying to just figure out how to read battery SOC without going outside, opening up with compartment and looking at the battery screen. Expecting to spend another $100 on a Shunt, or something. *sigh*