The Redback 40V 2.0A compact battery charger is compatible with any Redback 40V battery (2.0Ah/4.0Ah/6.0Ah) and features an LED status monitor to show precisely when your batteries are at capacity. Electronic monitoring of the individual battery cells extends the life of your battery. This high-quality charger is easy to use, store and mount. Easily slide the battery pack into place and let the charger take over from there. The green light will flash, indicating the charging process. When the light becomes steady, your battery is fully charged. Estimated recharge time: 70 min/2.0Ah battery, 135 min/4.0Ah battery, 200 min/6.0Ah battery. Rest assured, all 40V Redback products are backed by a 3-year warranty (all batteries backed by a 1-year warranty).