diy solar

diy solar

Cells from Luyuan and Box/BMS from Seplos to Australia

I was told by Seplos that the V16 BMS I was getting had Bluetooth functionality. It did not. I learned that the BT function is physically provided in the display module of the BMS, so while a V16 BMS might have Bluetooth "functionality" (whatever that means), there actually is no Bluetooth transceiver unless you specifically ask for a Bluetooth Display.

Yep, the Bluetooth is in the display itself. Based on what I'm seeing as functionality the display can communicate with the BMS and they have added another mechanism for tapping into that communication channel.

But consider this - why would you need Bluetooth on the battery? Do you really need that or this is going to be just another Bluetooth gadget burden?

My personal opinion is that the system should be set and forget. I'm buying a pretty expensive BMS that should take care of the battery. I don't want BMS that enables me to do its job.
 
There is an error in the 200A BMS Manual which has incorrectly labelled the CAN-L and CAN-H pinouts on the CANBus connector. The signals are in fact reversed. The manual for the 100A BMS is correct.

This is something that everybody should consider. It is not that CAN-L/CAN-H are swapped, but the whole pin numbering is in reversed order.

And the reason for that is in the standards - RJ45 standard ping numbering is from left to right when you are looking at the bottom of the RJ45 connector. In the manual, the pin numbering is based on the female port on the PCB. As result, it is not the standard one but is reversed.

Seplos not considering this an issue may have an impact on their sales. DiY community will hit issues with that and prefer other options. Recently I commented on a dedicated thread about that.
 
@Mariner62 how are the B Grade cells supplied by Luyuan performing?
I ordered my LF280K's around the same time as Mariner62, and mine have been excellent, I couldn't be happier.
I don't run my cells to their bleeding limits, but they've performed exactly as I need. I keep a close eye on my BMS statistics day to day and there doesn't appear to be any particular cell that has trouble charging or discharging.
Accoring to the BMS the pack has had 7 full cycles now, so still early days, but they seem to have settled in well.
 
Ok, to buy a ZKE 40 is around A$500. Too much investment. There is a cheaper option which discharges at 5A, but I would be testing till January with that one.

So, it's a nogo from me on the single cell tests. I will test as a battery. I'm happy with that test as it's how I plan to use the cells, and as @octal_ip noted, the result will be dictated by the weakest cell.

I've done this previously with 4 cell and 8 cell configurations and was happy with the results.
I think you're really underestimating the value of being able to to load test individual cells. I've learned so much about the performance of my cells by running all kinds of discharging tests and in a world where you have no idea if you're getting garbage Grade B or good Grade B a discharge test is the only way to really know for sure.

The ZKE Tech EBC A40L is $199 USD shipped right now on Aliexpress, there's this Atorch 40A fan discharger for $77USD shipped, and there's a new 50A tester under the Hel Tec brand name and some alphabet soup brand name like YDPSZ that I've seen under $200 USD shipped.
The Atorch can be extremely flexible with its voltage range but without charging the A40L and new 50A tester are really an amazing bargain. A 40A electronic load is typically more than $500, I can only think of two that have the ability to do 40A under $400. They will save your ass when one day you get sent shitty cells. I've seen sellers dispute series connected cells by using the argument that buyer has not properly top balanced blah blah blah with enough bullshit to confuse the arbitrator. My A20 cost me $90 USD shipped and it has already paid for itself in the refunds I've gotten (while still keeping the product in some cases). I regret getting the A20 due to its 85W limit but it does have the ability to charge up to 20V 4.5A (based on your power adapter) and discharge up to 30V as long as you stay under 85W and under 20A. So a bit more flexible and the A40L couldn't be found so cheap when I purchased the A20, the A40L used to be $270+ pretty much everywhere and this week I've seen it for $199 USD and $212 USD shipped.
At the very least a $35 to $40 USD shipped DL24 150W or 180W max 20A model is good to have around. They have several variants that do 20A, 23A, and 25A then the splicable version that depends on if you have 1, 2, 3, or 4 cooling units to do 25, 30, 35, and 40 amps at 150W, 300W, 450W, and 600W respectively but like I said once you pass the $40 USD mark just bite the bullet and get the A40L or the 50A tester.
ZKE Tech also make a tester that can handle batteries up to 100V (72V or 84V nominal) and do either 10A or 20A discharging. EBC-B10 and EBC-B20. I believe both have inputs for you to add your chargers leads if you want to set up cycling tests.
 
@Mariner62 how are the B Grade cells supplied by Luyuan performing?
Sorry just noticed this!
The Luyuan B grade cells are performing very well. I ordered some more (which had shipping delays), but both sets are good. I am happily working about 250Ah through them most days. No balance problems on either bank.
 
I think you're really underestimating the value of being able to to load test individual cells. I've learned so much about the performance of my cells by running all kinds of discharging tests and in a world where you have no idea if you're getting garbage Grade B or good Grade B a discharge test is the only way to really know for sure.

The ZKE Tech EBC A40L is $199 USD shipped right now on Aliexpress, there's this Atorch 40A fan discharger for $77USD shipped, and there's a new 50A tester under the Hel Tec brand name and some alphabet soup brand name like YDPSZ that I've seen under $200 USD shipped.
The Atorch can be extremely flexible with its voltage range but without charging the A40L and new 50A tester are really an amazing bargain. A 40A electronic load is typically more than $500, I can only think of two that have the ability to do 40A under $400. They will save your ass when one day you get sent shitty cells. I've seen sellers dispute series connected cells by using the argument that buyer has not properly top balanced blah blah blah with enough bullshit to confuse the arbitrator. My A20 cost me $90 USD shipped and it has already paid for itself in the refunds I've gotten (while still keeping the product in some cases). I regret getting the A20 due to its 85W limit but it does have the ability to charge up to 20V 4.5A (based on your power adapter) and discharge up to 30V as long as you stay under 85W and under 20A. So a bit more flexible and the A40L couldn't be found so cheap when I purchased the A20, the A40L used to be $270+ pretty much everywhere and this week I've seen it for $199 USD and $212 USD shipped.
At the very least a $35 to $40 USD shipped DL24 150W or 180W max 20A model is good to have around. They have several variants that do 20A, 23A, and 25A then the splicable version that depends on if you have 1, 2, 3, or 4 cooling units to do 25, 30, 35, and 40 amps at 150W, 300W, 450W, and 600W respectively but like I said once you pass the $40 USD mark just bite the bullet and get the A40L or the 50A tester.
ZKE Tech also make a tester that can handle batteries up to 100V (72V or 84V nominal) and do either 10A or 20A discharging. EBC-B10 and EBC-B20. I believe both have inputs for you to add your chargers leads if you want to set up cycling tests.

A compelling argument for some, however for those of us not ordering cells on a regular basis, it makes sense to run the them through their paces connected to the system first, then invest in a tester later if there seems to be a problem.

Like @Mariner62, my Luyuan B grade LF280K cells have been working perfectly (delivering 14kWh per charge) since they arrived, and have now been through about 20 full cycles, so I have no reason to spend the extra money to test them individually.

That being said, I recently purchased the ATORCH DL24 for just $22 USD including delivery, and fit my own heatsink. They're a great little tester, though have a flaw that can be mitigated with a very simple modification (15v zener to clamp the MOSFET gate/source over-voltage due to ringing).
 
~AUD200 per cell delivered in a batch of 16. Don't know yet if I'll be hit up for customs charges on arrival.
I got in contact with Amy to buy these 304ah cells, 16 in total to build own 48v system. She says cant do door to door as pack too heavy. Can only ship to closest port. How did you get them? Thanks
 
I ordered my LF280K's around the same time as Mariner62, and mine have been excellent, I couldn't be happier.
I don't run my cells to their bleeding limits, but they've performed exactly as I need. I keep a close eye on my BMS statistics day to day and there doesn't appear to be any particular cell that has trouble charging or discharging.
Accoring to the BMS the pack has had 7 full cycles now, so still early days, but they seem to have settled in well.
Are you also in Australia QLD?
 
I got in contact with Amy to buy these 304ah cells, 16 in total to build own 48v system. She says cant do door to door as pack too heavy. Can only ship to closest port. How did you get them? Thanks

I was also in contact with Amy recently, and she was hesitant to offer DDP, or to have all cells shipped in a single delivery. My last order was delivered to my door no problems, so I'm not sure what's changed. This is a real shame as Luyuan were building an excellent reputation for themselves.

I ended up ordering from another reputable supplier who had no problems with DDP and the list of terms I specified (no bloating or physical defects, >=280Ah capacity, QR code in tact, etc.). They were also quite a bit cheaper overall. Time will tell if the products are any good, but I feel I have enough recourse if the order isn't as specified.
 
I was also in contact with Amy recently, and she was hesitant to offer DDP, or to have all cells shipped in a single delivery. My last order was delivered to my door no problems, so I'm not sure what's changed. This is a real shame as Luyuan were building an excellent reputation for themselves.

I ended up ordering from another reputable supplier who had no problems with DDP and the list of terms I specified (no bloating or physical defects, >=280Ah capacity, QR code in tact, etc.). They were also quite a bit cheaper overall. Time will tell if the products are any good, but I feel I have enough recourse if the order isn't as specified.
I guess you cant say who you went with? ;-)
 
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