Why are the battery charge LEDs flashing on a Smart-UPS?
Option 1 : ... an XL ( Extended Run) model ... XL battery packs and replacement battery cartridges are available for purchase on our website at ... Each LED is an indication of battery charge in increments of (approximately) twenty percent: 20 , 40, 60 , 80, 100% (bottom to top). ... Similarly, if the total runtime for a particular UPS is 30 minutes with a low battery signal warning time set at 10 minutes, then the UPS will run on battery for 20 minutes before the low battery alert begins.