The CyberPower SE425G UPS Battery Backup is a very reliable, affordable, and good quality product. The only problem: It’s weird, non-standard Battery size which has become a problem to purchase. It’s very difficult to find a reliable source even on eBay or Amazon. The UPS comes with a VRLA Rechargeable Battery from B.B. Battery, model CPS3.6-12, and at the time I wrote this article, I was unable to purchase a replacement battery on their website.
Although I have installed dozens of these battery backups and they worked for years, I knew the battery would eventually give out. I had to find a solution, and I came across this product by BBM Battery, model SHR3.6-12: https://bbmbattery.com/products/shr3-6-12-bb-battery-12v-3-6ah-battery. I ordered a few of these batteries and the replacements are the exact same size and electrical specifications. The batteries fit right into the battery compartment in the SE425G and worked as expected. They also worked on the CyberPower CP425G3 smaller UPS.
Part No.: SHR3.6-12
Chemistry: Sealed Lead Acid/AGM
Dimensions: 4.02″ x 1.89″ x 2.59″
Terminal: T2 (.250″)