![](https://i0.wp.com/www.stevejenkins.com/blog/wp-content/uploads/2013/11/s20blk.jpg?resize=570%2C300&ssl=1)
This post is primarily a how-to for my own benefit, since I own a total of five APC S20 BLK battery backup units running a variety of things at the house from AV gear to a rack of servers. That means there’s a chance I’ll need to replace the battery […]