Stupidbright Stuidbright 8.4v Battery Charger with Full Charge Indicator. Works with All Bike Light Sets Using 8.4v Battery Packs SB Series, Gemini, Magicshine &#x2714; UNIVERSAL COMPATIBILITY: Works With All 8.4v Powered Bicycle Lights. SB SERIES, Gemini, Magicshine &#x2714; FULL CHARGE INDICATOR: Red indicates battery charging and Green when the battery is fully charged &#x2714; STUPIDBRIGHT&trade; LIFETIME WARRANTY: Never worry again. We offer 100% Money Back or Replacement Guaranteed &#x2714; OVERCHARGE PROTECTION: After a full charge, the charger shuts off any further charging to protect the battery pack &#x2714; 60 Day Money Back Guarantee: We offer a full 60 day satisfaction guarantee