What do the different LED lights and settings mean on a Schumacher battery charger manual?

I have a bad habit of letting my car battery die over the winter, so my Schumacher battery charger is an essential tool in my garage. One morning, I hooked it up to my dead SUV, but instead of the usual steady charging light, it was flashing red in a pattern I had never seen before, and it wasn't charging at all. I was worried the charger itself was broken. I found the faded sticker on the side with the model number SE-1052 and started looking for a manual online to decode the warning lights. I quickly found a page that hosted the exact owner's manual for my model. schumacher battery charger manual https://schumacher-electric.manymanuals.com/battery-chargers/se-1052/owners-manual-403 The manual explained that the rapid red flash pattern I was seeing indicated a bad connection to the battery terminals or that the battery voltage was too low for the automatic mode to engage. I cleaned the corroded terminals and switched it to the manual mode for a few minutes to bring the voltage up, and then it switched to charging normally. That manual saved me from buying a new charger and is now bookmarked on my phone for future troubleshooting.

I really appreciate this, the flashing red light code explanation in the manual saved me from buying a new charger.