I posted this on another forum but I see there are some Pylontech Engineers on this forum. Please see my current issue I am facing below with SegenSolar / Pylontech Batteries US2000b Plus models.
I have a 6 year old installation in a 4 x 5kW Axpert Inverter setup as attached with 20 x Pylontech US2000b Plus (And some new US2000C Top batteries in Cabinets for failed US2000b Plus Replacements). US2000b Plus Batteries started failing 1 or 2 at a time since 2 years ago with 900-1100 cycles on the batteries. Initially when installed in 2017 Pylontech approved the 53.2v Float/Absorption charge settings for the 10 year warranty and it was submitted to them by installer. 2 Years ago they replaced 2 batteries. The voltages on inverters was then adjusted by installer due to 2 batteries failing to a lower voltage 52.7v Absorption and 52.4v float, according to installer Pylontech’s new recommendation is lower voltages to prevent overvoltage which still indicates the batteries are charged 100% full after the settings changed, so voltages seemed fine. Earlier this year another 2 batteries started to discharge faster than other’s and Pylontech did not replace it and attributed it to overcharge voltages. How can 2 batteries in 2 cabinets fail out of 20 (4 x 5 Strings of batteries, 5 batteries per inverter) Insurance declined physical or electrical damage claim and attributed it to wear and tear. Pylontech should cover battery usage (Wear and Tear) for 10 years correct ? If warranty not covering these batteries and insurance not covering it under electrical/surge damage does anyone have a resolution here please ? Last week I noticed another battery discharging faster than other’s and since Pylontech is not replacing I opened it to check if swollen. It was swollen as attached as the previous ones which they did not replace so I did not care I if voided the warranty by opening it. Today another US2000b Plus started discharging faster than other’s. Some sample monitoring screenshots attached. The 10V Battery on the left side of image attached was swollen, on other 2 batteries the 30V right side was swollen. Totally random and different inverters on these batteries. All battery cycles since installed 6 years ago are less than 1200 Cycles. Since day 1 battery monitoring was done (1st ICC then then swopped to Solar Assistant), battery voltages never exceed 53.2v and the past year never exceeded 52.7v after lower voltages set on inverters. Cut-off voltage done before reaching minimum voltages around 20% battery remaining on cut-off but low voltage according to Pylontech warranty replacement was not the problem, overvoltage was. Battery temps as per 3 months graphs indicates battery temps are within suitable temp ranges. I can only monitor 8 batteries at a time due to US2000 Plus limitations but I swop the monitoring console cable to a different set of batteries every 3 or 4 months to check if batteries still good. So 6 Batteries failed out of 20 and Pylontech attributes this to overvoltage and only 2 replaced. 1 I opened so voided warranty and the one I checked today not opened yet. Any ideas since I will rather not recommend Pylontech for honoring their 10 years warranty at this stage. I also queried them dates of which overvoltages occured but they just ignored me.
what was the outcome of this as i have a few clients same issue and all settings are as per pylontechs recommendations ? Truth be told ive not had faith in the pouch cells they cannot retain their structure with out external compression
In the last week, I noticed my GoodWe ES5048 started rebooting every 30 minutes. Really annoying. While power didn’t drop, solar generation did.
Logging in to the inverter, I only saw battery temperature warnings. Which made me look at the battery cabinet. Only to find, my 2nd battery is looking almost depleted while the other 3 is around 70% soc.
Removed the battery from the pack, reconfigured the inverter to say there only 3 batteries now even though it is communicating via BMS (hence inverter reporting temp problem).
Now the inverter and remaining batteries are happy.
Anyways, walked past the battery yesterday only to see this:
Like, I didn’t even have to open it to know, something seriously wrong here.
Removed it from the garage attached to the house to another freestanding building, until it gets collected for the RMA process.
Battery was purchased in May 2021. So not even 4 years old. Cycled often as things go. The other one ordered at the same time is still going strong.
Wow, quite scary to see the amount of Pylontech issues lately.
Jaco is also currently busy talking to Pylontech on my behalf, as I have multiple issues on my bank of 6. It started with the newer U3000 going into error mode, and has now escalated to all at various times and under various load conditions.
Initial battery bank stats were exported and send to them and they have now requested additional information, that Jaco will come and extract.
I have always been recommending these batteries to everyone, based on how they initially performed, but after reading all the issues, I am a bit hesitant.
Also saw on zatech slack someone else also having swollen pylontech us3000c battery issues. So yeah, definitely something going on with the us3000c batteries.
My us3000b batteries are older and going strong still for now.
jip @tinuva - one of my 3 us2000s is at 25% whilst the other two and a us3000 are almost full… the decline happened over about two months and in the morning I’m taking it out of the bank, a while ago one of my pylon us2000s bloated and @JacoDeJongh managed the warranty issue creating the opportunity to go for a new us3000… lets see if there is bloating again - I’ll keep you guys posted… zzzzz
EDIT
the thing is we only tend to share the bad news - I’m sure there are 1000s of happy pylontech users, you just don’t hear about them… it is like vaccines - we don’t focus on the millions of kids who don’t get measles but are hellbent on blaming MMR for the statistical infinitesimal minority who get allergic reactions, even worse, blaming it for conditions totally unrelated to it.
Sorry a bit OT, anyone know what the Pylontech warranty state in terms of running batteries stand-alone with no BMS coms? I have a project coming up in which I’ll be running a Pylon UP2500 24v stand-alone with only a Victron MPPT charging it.
I know this is OT, but I wanted to add that people don’t quite understand that risk is composed out of both the severity of the outcome, and the likelihood of it happening. Literally, risk = likelihood x severity.
Yes, there is a likelihood that a vaccine can have an adverse effect, but that adverse effect is likely to be mild. Conversely, the likelihood of an adverse effect from actually getting the measles is like 3 in 10, and the adverse effects is anything from death to permanent disability, damaged eye sight, lost hearing, weak limbs, etc etc. And the Freaken R0 value of measles is 15. FIFTEEN! Covid is like 1.8.
Not the place, I know, but seriously… some people are just stupid.
Here’s my experience with Pylontech:
Since mid 2020 I have purchased a total of 28 Pylontech batteries (a mix of US2000B, US2000C, US3000C and UP5000). Over the 5 years I have had 4 x US2000B batteries fail (all from the same batch) as well as 2 x US2000C batteries. They were all either credited or replaced under warranty. In every case it was due to cell imbalances that the BMS could not correct. The batteries are cycled daily and those that failed were never overcharged or fully discharged.
I do not know whether this failure rate is above or below average for LFP batteries, but in all cases Pylontech’s support has been very good and the warranty claim process was painless.
I have been adding Pylontechs to my battery bank since January 2018, I now have 10 batteries, a mix of US3000, US2000C and US3000C.
In the last 7 years I have only had one battery give a high voltage alarm with one cell getting out of line. I pulled the logs from the US2000B and the battery from the bank and noticed the case was swollen. I then discovered that a second US2000B had also swollen but had no BMS alarms.
I had bought 4 US2000B’s with sequential serial numbers (same batch) and Pylontech asked me to return all 4 to be RMAd. Three out of the four had no BMS errors and the remaining two batteries had not swollen.
After a couple of days, Pylontech offered to replace all 4 with US2000C (which I did) or to pay out the value of the replacments, no deductions for wear and tear.
At the time of the claim, the batteries were nearly 6 years old and still under warranty.
I will definitely buy Pylontech again with confidence.
