Very small and compact desktop charger, controlled the current to boost-charge from small to medium sized Lead acid batteries, up to 60Ah. The 3-step charge characteristic will maintain the battery on top condition, even if left connected up to an indefinite period of time All models come with an attachable metal brackets from simple wall-mountable. Devices range from 60W to 100W power output, those exceeding 60W have a cooling fan Step 1: Boost stage The max. permissible constant current (4A-7A) passed into the battery until the voltage reaches a preset level of 14.4V. At the end of the stage the battery recovered about 80% capacity, the LED indicator will change from red to yellow Step 2: Absorption stage The voltage is constant, the charge current falls progressively until the elapse preset length of time. As the charge current decayed to a small value, the LED changes state from yellow to green-indicating battery full and the beginning of the maintenance charge Step 3: Maintenance stage The voltage is left floating at the level slight less than 13.8V, for long time care of battery Electrical safety standard: EN60335.2.29 and AS/NZ 3350.2.29:2001 EMC test: compliant with EN 55014-1/2 AC-input cord with plug for EU, UK, US, NZ and Australia Output short and reverse polarity protected Output termination fixed Case dimensions (W x H x D): 110 x 45 x 150 (700g) All models listed have either 3-step constant current or constant voltage characteristic: 12V-3A/6A (with selector switch) 12V-4A 12V-5A 12V-6A 12V-7A 24V-3A