Very small and compact desktop charger, controlled current to boost-charge form small to medium sized Lead acid batteries, up to 150Ah. The 3-step charge characteristic will maintain the battery on top condition, even if left connected over an indefinite period of time All models come with an attachable metal brackets from simple wall-mountable. Devices range from 110W to 150W power output, all have a cooling fan Step 1: Boost stage The max. permissible constant current (8A-10A), passed into the battery until the voltage reaches a preset level of 14.4V. At the end of this stage, the battery has 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 a preset length of time has elapsed. 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 or 3-pin IEC connector Output short and reverse polarity protected 2-way screw terminal block output termination Case dimensions (W x H x D): 110 x 50 x 180 (850g) All models listed have either 3-step constant current or constant voltage characteristic: 12V-4A/8A (with selector switch) 12V-8A 12V-10A 24V-4A 24V-5A