these devices are fine until you need… these devices are fine until you need them, they require constant management else they run into a firmware problem and them whatever was plugged into them like a refrigerator is no longer backed up, no warning nothing. unless you can afford to constantly monitor the device, you cannot rely on it to just "be dumb" until the firmware is updated. by time this happens its out of warranty. also currently cannot explain to anyone how it will not charge over the amp demand in ac wall mode. no one would take the time to understand that just plugging it into the 120v ac outlet isn't good enough for it to be a backup battery in ups mode. it still requires a 12vdc source to provide additional charge over the ac demand it may currently need. in short fine for someone who will charge it and use it as a massive cell phone booster battery, no someone who needs it to be an uninterrupted power supply

Faulty Power bank and they didn't even respond to my email Received a Zendure powerbank as a present and it's not working right. Stops charging external devices after the power level drops below 40% and then turns off. When I subsequently recharge the power bank it always starts charging from that same circa 40% mark meaning that I'm not getting close to the battery capactiy which I should be. Emailed Zendure with the problem 10 days ago and with a video of the problem and they didn't even have the courtesy to reply. TLDR: Faulty power bank and terrible customer service - buy another brand (Anker for instance have great customer service usually)

It is a scam It is a scam. Products are either not working or not working as advertised. Constant problems. Support not answering for months.

Super rank replacement I bought a zendure supertank power bank via amazon in Nov 22. I began experiencing issues in Jun 23 and contacted their customer service department directly to enquire if my power bank was still under warranty. Grace Huang took my query and resolved within a week. I received a brand new replacement power bank within two weeks. At this point I would like to say that zendure brand of power bank are extremely durable and reliable. My family have three in total with two being almost 4 years old with no problems. Thanks Grace for your help, much appreciated, Neville.

Grace at Zendure was responsive and… Grace at Zendure was responsive and professional. I was disappointed that my £48 battery pack had completely stopped working after only 3 months. (I paid that much bc NYT Wirecutter rated the product so highly.) Grace/Zendure honoured the warranty and sent a replacement within a week of my being in touch about the problem. Graces communication was always clear and prompt. Hopefully this one will be top quality as hoped.