Battery Preconditioning

[Noel]

Apologies, I previously raised this subject, however, it appears that there was confusion regarding ‘Battery Preconditioning’, and using the iSmart app’s facility to pre-heat the cabin/seats etc.

To reiterate, my question relates to understanding exactly what PRE CONDITIONING THE (traction) BATTERY achieves, how and when to use it, and what are the benefits of doing this, prior to charging the battery, or using the car.
I understand the basics, that a warm battery provides greater capacity and efficiency, and that this allows it to accept more charge, and to provide more power. However what I’m not sure of is, how much more electricity is used/required to accomplish this, than the overall assumed benefits provide? Or does using preconditioning simple provide protection, and ensure the longevity of the battery.
Any enlightenment, would be gratefully received, thanks Noel.

 

[T1 Terry]

The battery heating is more to do with not damaging the cells in the battery if attempting to charge them below 0*C .... is the figure most commonly used .... but that really depends on the electrolyte mix in the cells regarding the min. temp they should be charged at ......
The risk is the lithium directly coating on the separator sheet that allows the lithium ions to cross from the anode to cathode and return, any coating on the separator sheet is a prime spot for other garbage called dendrites, to collect and build layers on ..... eventually a spike is created that can pass through the separator to short the anode to the cathode ...... in reality, it's just building each side of the separator sheet, the platinum is just an excellent conductor .....
The first few times, the spike burns off, but it creates a rounded platform for more layer to build on .... until it doesn't simply burn away, but slowly discharges the cell, heating the electrolyte and killing the cell ..... lose a cell and that is the start of a cascading battery failure ........

A battery at 25*C will hold the most capacity, at 60*C it will deliver the most energy over a given time period .... to the detriment of cycle life, so 25*C is the best for a long cycle life

Are you sorry you asked now

T1 Terry

 

[Herandnu]

From what I read optimal charging temperature is between 20 and 40⁰C. At very low temperatures fast charging can cause lithium plating of the anodes which permanently reduces battery capacity. However, I don't think the HS battery will ever be charged at very high speeds.
Another benefit of preconditioning is for regenerative braking. At very low temperatures regenerative braking may be limited.
Also, at low temperatures the battery resistance is higher, so that charging time will increase.

From Gemini AI:

Dedicated battery preconditioning is usually reserved for cars that support DC Fast Charging (Rapid Charging).
AC Charging Only: The MG HS PHEV only supports AC charging (up to 7kW). Because AC charging is relatively slow, the battery doesn't need to be at a specific high temperature to accept the current safely.
The Engine Factor: Unlike a pure EV, if the battery is too cold to provide full power, a PHEV can simply start the petrol engine to help move the car and generate heat for the system.
3. Tips for Winter Driving
Since you can't manually "warm the battery" like you can in a Tesla or an MG4, here is the best way to manage the MG HS PHEV in cold weather:
Stay Plugged In: Always leave the car plugged in until the moment you leave. This allows the battery management system to use wall power to keep the battery within a safe operating temperature.
Use Scheduled Charging: Setting the car to finish charging right before you leave ensures the battery is naturally warmer due to the chemical activity of the charging process itself.
The "EV Mode" Challenge: In very cold temperatures (below 0°C), you may find that "EV Mode" is temporarily unavailable or the engine starts automatically even if the battery is full. This is normal—the car is using the engine to generate heat for the cabin and to protect the battery.