I am in the same boat, I have four Pylontech (US3000) batteries installed by an accredited installer. I am using Deye Hybrid inverter, and my understanding is that the BMS is controlled by Pylontech. I started getting alarms, and battery not holding its charge. I contacted Pylotech, they directed me to SolarDeity for evaluation/ repairs. The oldest battery is swollen, the second oldest battery has started swelling, (they have worked well for 4 years). Pylontech have gone silent on this warranty repair. After numerous follow-ups, they claim that the batteries are out of warranty and not registered, yet it is registered with a registration number form Pylontech (10-year warranty). SolarDeity has also confirmed that it is under warranty. Then they asked why I brought them the battery and not the installer, therefore it is not covered. They also said that I should return it to the company that we bought it from, yet Pylontech instructed me by e-mail instructed me to take it to Solardeity in Wynberg. They have also stated that they cannot read the battery logs, and they are probably looking for another reason not to honour the warranty. In my opinion, Pylotech are look for reasons not to honour their warranty and their warranty is not worth the paper it is written on. Buyers beware…..