🔋 Long-lasting SR521SW 379 Watch Battery Pack - 10pc Alkaline Batteries, 1.5V Review

As far as I can tell this item is excellent value for money. I just replaced the clock and it works so only time will tell for how long. But there are nine other batteries at such a great price, so no complaints.

I bought these because they cost 20% less than good quality batteries. Guess four out of five are dead off the map! To check, I used my button battery tester. I'm not sure about the durability, but I'll pay for the price. I will not buy again. Lesson learned.

First, the expiry date is 2022, which is ridiculously short and makes them look old. Second, I needed a battery of this size for 4 hours. As a test I bought this and Renata in the same size. They worked at 3am but the new relic didn't work. I switched it to a Renata battery and it worked fine. Definitely don't buy these.