- Vehicles
- Cars
Please Slow-charge the Vehicle
MG 'Please Slow-charge the Vehicle' in car: battery balance
Risk level
Low
Usually safe to check without specialist tools.
Urgency
Low
Quick answer
The message 'Please Slow-charge the Vehicle' on an MG electric car (such as the MG4 or MG5) asks you to complete a full slow AC charge (recommended up to 11 kW) so the battery management system can equalise the charge across every high-voltage battery cell.
Safety first
Stop and check this first
- Only connect your MG to AC charge points that comply with IEC 61851 and IEC 62196, verify that the charging identifier symbols match, and always clear excess water or debris from the port area before plugging in.
- Never attempt to pull the charging plug out by force while the charging port electronic lock is engaged: finish or stop the charge and unlock the vehicle first to avoid damaging the locking mechanism.
Safe checks you can perform
- Carry out a full slow AC charge on a charger rated up to 11 kW
- Allow the extra equalisation time after the display reaches 100%
- Check that no high-voltage battery fault lamp is lit in READY mode
Leave these tasks to a qualified professional
- Do not attempt this professional task: Battery management system (BMS) cell balance and health inspection
- Do not attempt this professional task: Combined charging unit (CCU) check and BMS calibration
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Battery management system (BMS) cell balance and health inspection
What they doIf the message remains after a full slow equalisation charge, an MG Authorised Repairer reads the BMS data to inspect individual cell voltages and balancing status.
They must show youthe BMS diagnostic report showing cell voltage spread and equalisation status.
In writingthe cell voltage readings, any stored BMS fault codes and the battery health assessment.
Combined charging unit (CCU) check and BMS calibration
What they doQualified MG technicians verify that the Combined Charging Unit (CCU) and BMS transition properly into equalisation mode at the end of AC charging and apply any required updates.
They must show youthe instrument pack message centre with 'Please Slow-charge the Vehicle' cleared after verification.
In writingthe checks or calibrations performed on the CCU and BMS and confirmation of normal slow-charge equalisation.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Carry out a full slow AC charge on a charger rated up to 11 kW
- Who:
- you, using an AC charging point that meets IEC 61851 and IEC 62196.
- How:
- switch the vehicle power system OFF, close all doors, connect the 7-pin charging plug to an AC slow charger with an output not exceeding 11 kW (up to 7 kW single-phase or 11 kW three-phase), and lock the vehicle.
- Result that matters:
- providing the full slow charge that the battery management system requires to reach 100% and enter cell equalisation mode.
- If charging starts normally on the instrument pack:
- leave the car plugged in until both 100% charge and equalisation finish.
- If a charging fault indicator lights up or charging will not start:
- inspect the connection or contact an MG Authorised Repairer.
- Evidence to keep:
- a photo of the 'Please Slow-charge the Vehicle' prompt and the charging information screen on the cluster.
Evidence: MG4 Electric (MY23) Owner's Manual · MG5 Electric Manual del usuario
Allow the extra equalisation time after the display reaches 100%
- Who:
- you, planning enough parking time for the full slow charge and cell balancing.
- How:
- do not unplug as soon as 100% appears: on the MG4 an AC charge including equalisation takes at least 7.5 to 14 hours depending on battery pack type and phase supply (about 4.9 to 8.5 hours on the MG5), and up to 3 times longer on a domestic socket.
- Result that matters:
- letting the battery management system finish equalising every cell before unlocking and disconnecting the plug.
- If the slow-charge prompt clears after the full equalisation cycle finishes:
- the cells are balanced again.
- If you unplugged before equalisation completed:
- the message may reappear on the next drive.
- Evidence to keep:
- start and finish times of the slow AC charge session and the final state of charge shown on the instrument pack.
Evidence: MG4 Electric (MY23) Owner's Manual · MG5 Electric Manual del usuario
Check that no high-voltage battery fault lamp is lit in READY mode
- Who:
- you, checking the instrument pack after disconnecting the charger.
- How:
- unlock the car, remove the charging plug without forcing the electronic lock, start the vehicle into READY mode and verify that the High Voltage Battery Pack Malfunction Indicator is not illuminated.
- Result that matters:
- confirming that the prompt was only a routine equalisation reminder rather than an active high-voltage battery fault.
- If no fault warning lamps or messages remain:
- the car is ready for normal driving.
- If the prompt persists after completed slow equalisation charges or a fault lamp lights up:
- contact an MG Authorised Repairer.
- Evidence to keep:
- a photo of the instrument pack message centre in READY mode after the slow charge.
Evidence: MG4 Electric (MY23) Owner's Manual · MG5 Electric Manual del usuario
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Vehicles
- Brand
- MG
- Product type
- Cars
Known code variants
- MG carga de compensación
- MG equalisation charging message
- MG4 Please Slow-charge the Vehicle
- MG5 realice una carga lenta del vehículo
- MG5 slow-charge battery message
- Please Slow-charge the Vehicle
- Realice una carga lenta del vehículo
What it means
In the MG owner's manuals (MG4 Electric and MG5 Electric), the instrument pack message centre displays 'Please Slow-charge the Vehicle' ('Realice una carga lenta del vehículo') when an equalisation charge has not been carried out for some time. MG explains that equalisation charging occurs after a normal charging process reaches 100%, when the battery management system enters a mode to equalise the charge of every cell, and that carrying out a full slow charge (recommended at an output not exceeding 11 kW) is the only way for the high-voltage battery to reach its optimal equilibrium state. This reminder alone does not prove a battery fault.
Warnings and stop conditions
- Mediumsource verified
Only connect your MG to AC charge points that comply with IEC 61851 and IEC 62196, verify that the charging identifier symbols match, and always clear excess water or debris from the port area before plugging in.
Evidence: MG4 Electric (MY23) Owner's Manual · MG5 Electric Manual del usuario
- Mediumsource verified
Never attempt to pull the charging plug out by force while the charging port electronic lock is engaged: finish or stop the charge and unlock the vehicle first to avoid damaging the locking mechanism.
Evidence: MG4 Electric (MY23) Owner's Manual · MG5 Electric Manual del usuario
Symptoms and causes
Probable causes · in order
- Equalisation slow charge not carried out for a long periodCommon
The MG manual states that the message centre displays 'Please Slow-charge the Vehicle' whenever an equalisation charge has not been completed for some time.
Evidence: MG4 Electric (MY23) Owner's Manual · MG5 Electric Manual del usuario
- Repeated rapid DC charging or partial charges below 100%Common
MG notes that rapid chargers charge the battery up to 80% in about 40 to 60 minutes and do not fully charge or equalise the pack; only a full slow AC charge reaches equilibrium.
Evidence: MG4 Electric (MY23) Owner's Manual · MG5 Electric Manual del usuario
- Vehicle returning to use after a long period of storagePossible
The MG manuals specify that an equalisation slow charge must be carried out before using the car after a long period of storage or non-use.
Evidence: MG4 Electric (MY23) Owner's Manual · MG5 Electric Manual del usuario
Virtual technician
Does Please Slow-charge the Vehicle still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
MG4 Electric (MY23) Owner's Manual
MG Motor Europe · 2023 · manual
- 2
MG5 Electric Manual del usuario
MG Motor Europe · manual
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