Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: 50% failure rate, out of the box

I've been using these batteries for over a decade. I usually buy 10 at a time. The last batch I purchased had a 50% failure rate. Opening the sealed package had batteries with leaks, discolored bodies and low voltage.Several attempts at contacting the manufacturer, including filling out the RMA form have been 100% ignored. They even have section on the website dedicated for RMAs for the batteries, so it's clear that they know about the problems.Won't ever touch anything with the Ultralife name on it.There are now other choices such as Energizer for lithium 9V cells. At least they actually honor their warranty.