EGO ST1521S PowerLoad Trimmer 15 in 56V Cordless String Trimmer with Automatic Line Feed CHG-RED-FLASH Error Fix: Charger Flashing Red Light

Error code CHG-RED-FLASH on the EGO ST1521S PowerLoad Trimmer 15 in 56V Cordless String Trimmer with Automatic Line Feed means: Charger Flashing Red Light. The charger LED is flashing red, indicating a charging error — the battery may be too hot or too cold to charge, the battery cells may be out of balance, or the battery has an internal fault; remove the battery, let it reach room temperature (50-85°F), clean the contacts, and retry; if the flashing persists across multiple charge attempts, the battery may need replacement

The most successful fix is "Test Battery Health and Replace if Faulty" (hard difficulty, ~45 minutes). Estimated DIY cost: $0-$20. HomeMD has 2 community-ranked fixes for this error.

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Yes — the top-ranked community fix ("Test Battery Health and Replace if Faulty") is rated hard difficulty and takes about 45 minutes. Tools needed: Digital multimeter, Battery analyzer (optional).

DIY cost: $0-$20. Professional repair typically costs $150-$200. Many homeowners save money by trying the top-ranked community fix first.

The EGO ST1521S PowerLoad Trimmer 15 in 56V Cordless String Trimmer with Automatic Line Feed has 8 other known error codes, including: BAT-1-FLASH (Battery Single LED Flashing), BAT-COLD (Battery Too Cold to Operate), BAT-HOT (Battery Overtemperature Protection), BAT-LEDS-OFF (Battery LEDs Not Lighting Up), BAT-NOT-RECOGNIZED (Battery Not Recognized by Tool), and 3 more.

Error code CHG-RED-FLASH also appears on 11 other EGO models: CS1401 14 in 56V Brushless Motor Cordless Chainsaw with Rapid Reload Chain Tensioning, EGO POWER+ CS1804 18-Inch 56V Cordless Chainsaw with Chain Tensioning, EGO POWER+ EA0800 56V 8-Inch Cordless Edger, EGO POWER+ HT2411 24-Inch 56V Cordless Hedge Trimmer, EGO POWER+ LB6000 56V 615 CFM Cordless Leaf Blower, EGO POWER+ LB6504 56V 650 CFM Cordless Leaf Blower, and 5 more. The fix may vary by model, so check each model's specific page for tailored repair steps.