5-year warranty promised – no help with defective batteries
I bought two 12V 100Ah LiFePO4 batteries from Batteryzone in September 2022. The product page clearly advertised a 5-year warranty. Both batteries developed the exact same serious defect on cell 3: During charging, cell 3 rises much faster than the others and triggers overvoltage protection (OVP). During discharging, cell 3 drops sharply and triggers undervoltage protection (UVP). The problem has been present since late 2023. I reported it multiple times and sent a formal warranty claim with a deadline of 7 July 2026, including proof from the Wayback Machine showing the 5-year warranty advertisement. To this day, there has been no substantive response — no acceptance, no justified rejection. They only suggested returning the batteries to China at my own expense, without offering any safe, prepaid solution suitable for large LiFePO4 batteries. The advertised 5-year warranty turned out to be worthless in practice. Extremely poor communication and no problem resolution. I strongly advise against buying lithium batteries from Batteryzone.