Viomi V5 Pro 2 Replacement Unit Is Also Defective

I received a Viomi V5 Pro 2 robot vacuum as a giveaway prize from a private individual. Although I have had the device for only two days, I have already encountered a serious battery performance issue. If I leave it on the charger for an entire day without using it, it shows a full 100% charge. However, after cleaning a small area of only about 20 square meters in a single session, the battery level drops to around 30%. I did not expect such poor performance from what was supposed to be a brand-new product.

This is actually the third unit I have received. The first robot arrived with a sensor malfunction, and I had to send it to the authorized service center before I could even use it. When it was returned, it still had the same sensor problem. I was then told that a replacement unit would be sent, but the replacement arrived with this battery issue instead. After three different units, I still do not have a properly functioning robot vacuum. The repeated replacements have wasted a great deal of my time and left me extremely disappointed.

I cannot accept receiving a product advertised as new that continues to have serious defects. I request that the authorized service center perform a thorough inspection of the battery and overall performance of this robot vacuum and either replace it with a genuinely new, defect-free unit or provide a clear and permanent solution. After dealing with this issue multiple times, I am still unable to use the product as intended. I expect my concerns to be resolved promptly and would appreciate a clear written explanation of what has caused these repeated problems.