Chery Tiggo 7 PHEV
PHEV Plus
Read this variant's specsAfrica-wide car guide · Start simple, go deeper
EV Batteries, Range and Charging Explained: kWh, kW and Charging Time
Think of a battery as an energy cupboard and charging power as the rate at which it is filled. Cupboard size and filling speed are separate questions.
Battery, inverter and motor: follow the energy
Start hereThe battery stores energy, electronics control it, and the motor turns it into movement.
A closer look
A traction battery supplies DC electrical energy. An inverter controls the electrical supply to an AC traction motor; architectures and motor types vary. Reduction gearing and a differential pass motor output to the driven wheels. A separate low-voltage system powers many controls and accessories.
Packaging is not universal. A BEV may use an underfloor pack, while a PHEV also carries combustion and fuel systems. A range-extender layout differs again. Use the actual architecture, not a generic EV cutaway, when discussing a named vehicle.
Cells, modules, packs—and the usable part
Start hereSmall cells are grouped into a battery system. The driver normally cannot use every bit of its total stored energy.
A closer look
Gross or total capacity and net or usable capacity describe different boundaries. Protective buffers and control limits can restrict the accessible portion. Some designs arrange cells directly in the pack rather than using conventional separate modules, so 'cell–module–pack' is one architecture, not a rule for every EV.
The battery-management system monitors and controls operation. State of charge estimates how full the accessible battery is; state of health assesses aspects of its condition relative to a defined baseline. A dashboard at 100% is not a laboratory claim that every cell has its maximum theoretical energy.
- Compare usable capacity with usable capacity.
- Keep the temperature, test method and baseline beside a battery-health result.
Estimate range without pretending it is guaranteed
Start hereDivide the energy you can use by how much the car needs for each kilometre.
A closer look
An illustrative 60 usable kWh at 15 kWh/100 km gives 400 km by simple division. At 20 kWh/100 km the same energy gives 300 km. These examples exclude any extra reserve and are not predictions for a named car. Speed, temperature, gradients, tyres, load and cabin conditioning can change consumption.
Use a reserve and a route-specific estimate for trip planning. A homologated range remains a test-cycle result. A PHEV or range extender's electric-only distance and its combined petrol-plus-battery distance must never be placed in the same 'EV range' column without explanation.
AC vs DC charging: where does conversion happen?
Start hereWith AC charging, the car's onboard charger does the conversion. With DC charging, that conversion happens in the charging equipment.
A closer look
For AC charging, the vehicle's onboard charger converts incoming AC to battery-compatible DC under system control. DC equipment supplies controlled DC through the vehicle's supported DC charging path. The vehicle still regulates the requested power and protects the battery; bypassing the onboard AC charger does not bypass battery protection.
Useful power is constrained by the vehicle, charging equipment, supply, cable and operating conditions. Connector shape alone does not establish charging speed, electrical compatibility or communication support. Check the exact market version; not every PHEV supports DC charging.
Charging time: use energy added and average power
Start hereA peak is the fastest moment. Your whole charging stop includes slower moments too.
A closer look
Approximate battery charging time is energy added divided by average battery-side power. Adding an illustrative 30 kWh at an average 60 kW takes about 0.5 hours. The charger's nameplate power is not necessarily the session average, and wall energy can exceed energy stored because of losses and conditioning loads.
DC power commonly changes with state of charge, temperature and battery limits. A 10–80% claim needs its stated conditions; it is not a 0–100% promise. A flat calculation using the peak kW often understates time. Compare the complete relevant window and include arrival, connection and queuing in your travel plan.
Regenerative braking returns some energy, not all of it
Start hereDuring slowing, the motor can work as a generator and put some energy back into the battery.
A closer look
Regeneration recovers part of the vehicle's kinetic or downhill potential energy. Tyre grip, motor/inverter limits, charge acceptance, temperature and state of charge can constrain it. Friction brakes still provide braking where needed; a full or cold battery can change the feel and available regeneration.
A safe, smooth driving routine helps avoid unnecessary energy demand. Regeneration does not create a perpetual-motion car: conversion losses and road resistance remain. Follow the manufacturer's driving and charging advice rather than treating one-pedal operation as a substitute for understanding the brake pedal.
Use the principle; check the actual system
- Document gross/usable capacity, software version, temperature and measurement boundary.
- For charging complaints, separate charger limit, vehicle request, supply constraints and battery conditioning.
- Use the manufacturer's battery-health procedure; a range estimate alone is not a capacity test.
- High-voltage inspection, isolation and repairs require trained personnel and model-specific procedures. Do not open a pack or probe orange cables.
This is educational context, not an OEM service procedure. Use current instructions for the exact vehicle and market before measurements, repairs or safety-critical work.
Your practical checklist
- Keep the range test cycle beside the distance.
- Check usable capacity and both AC and DC limits.
- Plan charging around an ordinary week's parking.
- Read the battery warranty's capacity conditions.
- Ask for a compatible charging demonstration and a backup charging option.
Explore examples in South Africa
These links rotate within your selected country. Open an exact variant to check its recorded specifications; the teaching diagrams above do not represent these models.
Foton eTruckmate
eTruckMate
Read this variant's specsDongfeng BOX
BOX E2 430
Read this variant's specsBYD SEALION 7
Premium EV RWD
Read this variant's specsQuestions worth asking
What is the difference between kW and kWh?
kW is power: the rate of energy transfer or work. kWh is an amount of energy. One kW maintained for one hour transfers one kWh.
Can a 150 kW charger always charge my car at 150 kW?
No. The car, connector, equipment, supply and battery conditions can limit the actual power, which may also change throughout the session.
Is gross capacity the same as usable capacity?
No. Usable capacity describes the accessible energy under a defined operating boundary; total capacity can be larger.
Does regeneration replace the brakes?
No. Friction brakes remain necessary and regeneration can be limited by grip, battery state and operating conditions.
Why does EV range fall on some journeys?
Consumption changes with speed, temperature, terrain, load and conditioning. Use a journey-specific estimate and reserve rather than assuming a test-cycle figure is guaranteed.
Sources and further technical reading
These references support the principles, not the specifications of every car. Regional manuals and test protocols have their own scope; never transfer one vehicle's limits or legal rules to another.
- US DOE: all-electric vehicle operation and range
- US DOE: charging infrastructure
- US DOE: electric-vehicle batteries
All numerical examples in this guide are labelled illustrations. Technical images simplify the mechanism; they are original Hagalu teaching artwork, not manufacturer-approved parts drawings.