How to charge a mild hybrid

Battery charging editorial

Mild hybrids are vehicles equipped with both an internal combustion engine (ICE) and a small electric generator / motor, which assists the engine during starting, cruising or hard acceleration. The 48V battery which powers the hybrid system is recharged using the vehicles kinetic energy through regenerative braking. The generator captures the energy during coasting and braking to be stored and used for restarting the engine and acceleration. Even though the electrical system is recharged by generative breaking, you still need to charge the 12V battery. You need the 12V system for almost all of the functions in your car such as air conditioning, lights, opening of the doors, the radio, windows etc. 

Generally, mild hybrids run on a 48-volt electrical system to operate the starter motor/ drive assist. This system powers components that otherwise would have been powered by the engine, allowing the vehicle to operate more efficiently. The integrated starter generator ISG is an additional source of power for overtaking or accelerating but also acts as a starter motor to run the start stop system, and a generator to charge its own 48v battery. 

Such systems offer gentle electrical assistance to the engine but not enough for the vehicle to run only off electricity, the majority of power for the vehicle still comes from fuel. Mild hybrids are said to be up to 15% more efficient than traditional ICE vehicles – running 100% on fuel. 

In most cases, a battery charger that matches the engine’s 12V capacity is enough to charge the 12V battery. However, in some cases you might need at least 20 amps to charge the battery, by using something like the CTEK PRO25S battery charger that delivers up to 25 amps. 

The PRO25S is the ultimate charger for showrooms or workshops. It’s portable, flexible and compatible with all types of 12V batteries, including lithium (LiFePO4) batteries. It has a reconditioning mode to restore deeply discharged batteries. It has many in-built safety features that make it completely safe for the battery and the vehicle’s sensitive electronics.  

The PRO25S is also spark proof and reverse-polarity protected which means that it protects both the user and the battery. It even has a built-in temperature sensor to maximise the charge levels. 

But before you start charging, check with your workshop or dealership to learn exactly what your vehicle needs and how you should charge it.