Horsefly
Solar Wizard
I have two JK model b2a8s20p BMS. One is still great, one - the more recent one - has completely failed with very little use. NOT GOOD.
Background:
I had built an 8S 230Ah system for our cabin (see here) with a JBD BMS. I already had since built 3 other JBD based batteries and was pretty happy with them. The app was pretty crappy, and the passive balancing was pretty pathetic given the size of the systems we were building. Still, I was OK with all that. (Flavor of the month, I guess)
I had been reading here about the JK BMS, and it was pretty compelling: Much better app, and really good active balancing. Everything else was positive. Early in 2022, I decided to build a second 8S system (see here) and decided to use the B2A8S20P from JK. I was really impressed. Great BMS, great app. I was so impressed, I decided to order a second JK-B2A8S20P in (I think) early May, to replace the JBD that I had installed at our cabin. Unfortunately, the order could not be placed because they were changing the design to add heating control (which I did not need) to the BMS. I decided it was still worth the wait. I eventually ordered the BMS, and although I specified (and paid) for without the heat control, the one I got came with the heat control.
Skipping the details, I set up and installed the JK-B2A8S20P (new, with heat control) as a preplacement for my JBD BMS on one of my trips to the cabin. The morning after the switch, the sun came up and started charging the battery, and it was clear something was wrong. The Schneider Conext SW4024 Inverter/Charger (connected to the same battery) started making very strange arcing / hissing noises. I've posted about it in the board, but can't find the thread. I immediately switched back to the JBD (with no issues), and all was well.
I put the new JK BMS on my newer 230Ah 8S pack, and on my next visit to the cabin tried to plug that pack in in parallel with the JBD pack. Through a few days of testing, whenever the JK pack was connected the same arcing / hissing noise came from the Schneider equipment. When the JK pack was disconnected, all was well.
I PM'd @Nami about this issue, but of course never heard anything in return.
The 230Ah pack with the newer JK BMS remained on a emergency backup system at my home in Denver, on a hand-truck with a MidNite Solar 3000W inverter/charger (thanks to Lithium Solar channel on YouTube for the idea). I've partially discharged the battery twice this fall, and changed it up to about 70% again two weeks ago.
Yesterday, I connected the JK app on my phone to the BMS just to check the status. It went crazy, alarming continuously and reporting that none of the cells matched the configured voltage, and allowed no discharge or charge. I replaced the BMS with my original JK-B2A8S20P (pre-heater-function) and it immediately said all was well, cells were within 1mV, and pack was at 26V.
So the newer heater-enabled BMS is crap. Lots of line noise (potentially damaging), and the whole thing crapped out. I had it for about 6 months, but in truth it had been through perhaps 4 charge / discharge cycles. Rubbish. I'm really sad. Turns out, JK BMS was truly just the BMS flavor of the month.
I'm not as active on the forum any more (too many other things), but I assume @Nami has gone the way of Michael B Caro.
Background:
I had built an 8S 230Ah system for our cabin (see here) with a JBD BMS. I already had since built 3 other JBD based batteries and was pretty happy with them. The app was pretty crappy, and the passive balancing was pretty pathetic given the size of the systems we were building. Still, I was OK with all that. (Flavor of the month, I guess)
I had been reading here about the JK BMS, and it was pretty compelling: Much better app, and really good active balancing. Everything else was positive. Early in 2022, I decided to build a second 8S system (see here) and decided to use the B2A8S20P from JK. I was really impressed. Great BMS, great app. I was so impressed, I decided to order a second JK-B2A8S20P in (I think) early May, to replace the JBD that I had installed at our cabin. Unfortunately, the order could not be placed because they were changing the design to add heating control (which I did not need) to the BMS. I decided it was still worth the wait. I eventually ordered the BMS, and although I specified (and paid) for without the heat control, the one I got came with the heat control.
Skipping the details, I set up and installed the JK-B2A8S20P (new, with heat control) as a preplacement for my JBD BMS on one of my trips to the cabin. The morning after the switch, the sun came up and started charging the battery, and it was clear something was wrong. The Schneider Conext SW4024 Inverter/Charger (connected to the same battery) started making very strange arcing / hissing noises. I've posted about it in the board, but can't find the thread. I immediately switched back to the JBD (with no issues), and all was well.
I put the new JK BMS on my newer 230Ah 8S pack, and on my next visit to the cabin tried to plug that pack in in parallel with the JBD pack. Through a few days of testing, whenever the JK pack was connected the same arcing / hissing noise came from the Schneider equipment. When the JK pack was disconnected, all was well.
I PM'd @Nami about this issue, but of course never heard anything in return.
The 230Ah pack with the newer JK BMS remained on a emergency backup system at my home in Denver, on a hand-truck with a MidNite Solar 3000W inverter/charger (thanks to Lithium Solar channel on YouTube for the idea). I've partially discharged the battery twice this fall, and changed it up to about 70% again two weeks ago.
Yesterday, I connected the JK app on my phone to the BMS just to check the status. It went crazy, alarming continuously and reporting that none of the cells matched the configured voltage, and allowed no discharge or charge. I replaced the BMS with my original JK-B2A8S20P (pre-heater-function) and it immediately said all was well, cells were within 1mV, and pack was at 26V.
So the newer heater-enabled BMS is crap. Lots of line noise (potentially damaging), and the whole thing crapped out. I had it for about 6 months, but in truth it had been through perhaps 4 charge / discharge cycles. Rubbish. I'm really sad. Turns out, JK BMS was truly just the BMS flavor of the month.
I'm not as active on the forum any more (too many other things), but I assume @Nami has gone the way of Michael B Caro.