Is your CyberPower RB1290 UPS beeping or not holding a charge? It's probably the battery. This is a direct replacement sealed lead-acid AGM battery, 12 volts and 9 amp-hours (Ah). It's the exact size and type needed for that model. The brand is ECIPOWER, model BLHFM12_9-26. AGM batteries are maintenance-free and perfect for backup power applications. This will restore your UPS's runtime, keeping your computer, modem, or other critical devices running during a power outage. Includes a 1-year warranty. Note: California Prop 65 warning applies. Replacing a UPS battery is usually very easy – just open the unit, swap the old one out, and reconnect the terminals. Save money over buying a whole new UPS! Keep your backup power working.