Bosch C3 Battery Charger

What types of batteries is the Bosch C3 compatible with?

The Bosch C3 is suitable for charging and trickle charging 6 V and 12 V lead acid batteries, including WET batteries (with liquid electrolyte), GEL batteries, AGM (absorbent glass mat), and VRLA batteries. Battery capacity ranges from 6 V (1.2 Ah–14 Ah) or 12 V (1.2 Ah–120 Ah). It is not intended for dry or non-rechargeable batteries. (Page 3)

How do I correctly connect the C3 charger to a battery?

Connect the red (+) terminal of the charger to the (+) terminal of the battery first, then connect the black (–) terminal to the (–) terminal of the battery (or to the car body, well away from fuel pipes). Make sure both terminals are firm before connecting the power cord to the mains. Never connect the power cord to mains current before the terminals are securely attached. (Page 5)

What is the correct order for disconnecting the C3 charger from a battery?

First, switch the charger to standby by pressing the Mode selection button. Then disconnect the power cord from the mains current before disconnecting the (–) terminal (black) from the battery, followed by the (+) terminal (red). Always disconnect the power cord from the socket before disconnecting the charging cable from the battery. (Page 5)

Which charging mode should I use for a 12 V AGM battery in cold conditions?

Mode 4 (12 V, 14.7 V / 3.8 A) is suitable for batteries with a capacity of more than 14 Ah in cold state, or for many AGM batteries. Press the mode selection button to select Mode 4, and charging will start automatically after a few seconds. After successful charging, the unit automatically switches to trickle charge mode. (Page 6)

What does it mean if the reverse polarity LED lights up on the C3?

The reverse polarity LED (9) lights up when the (+) and (–) terminals have been interchanged on connection. The charger switches to standby mode and remains there until a different setting is made. This is part of the appliance protection function designed to prevent damage. (Page 6)

What is the pulse charging function and how do I activate it?

Pulse charging is an automatic charger function that cannot be selected manually. If the battery voltage in 12 V mode is between 8 V (±0.5 V) and 10.5 V (±0.5 V) at the start of charging, the charger switches automatically to pulse charging to help recover more or less flat batteries. Once the battery voltage rises above 10.5 V (±0.5 V), the charger automatically returns to the previously selected charging mode. (Page 6)