MG Windsor EV owners report DC charging cutting out: the BMS update fix

India's best selling electric car has a complaint that only shows up away from home. MG Windsor EV owners report that a DC fast charging session starts, the app or the charger screen shows power flowing, and then the session drops within seconds or a minute or two. Plug in again and the same thing happens.

EV India, reporting in July 2025, said owners raised this on Reddit, on LinkedIn and in owner groups, and named three networks where it kept happening: Zapp, EV Dock and Reliance Jio-bp. The same report said other cars, including MG's own ZS EV, charged normally on those chargers, which points at the car rather than the charger. Search results show the issue being discussed in Team-BHP's long MG Windsor EV ownership thread as well, but those pages would not open for me, so I am not quoting them.

I could open one owner thread, on the EV Electree forum, where a Windsor Pro owner described being left stranded twice because the car refused to start charging. It carries nine comments. One says DC charging was handled in a software update. The owner replied that the dealer had updated the software and the fault came back. Another comment suggested a workaround involving the kill switch before plugging in, which nobody in the thread confirmed. That is one thread and one car, not a pattern.

What the fix is

Both EV India and EVFY report the same remedy: a battery management system and high voltage battery software update, done at an authorised MG service centre, with dealerships calling customers in to schedule it. Both put the job at 30 minutes to about an hour. EVFY, writing on 2 July 2025, said at that point it was still waiting to see whether the fix worked, and noted the Windsor had crossed over 27,000 sales since its September 2024 launch.

I found no customer notice from JSW MG Motor India on its own newsroom about this update, and no service campaign document. So the official side here is thin: what exists is dealer level outreach reported by EV publications, not a published bulletin.

Why this one is not a DIY job

BMS and high voltage battery software are not owner serviceable. There is no app toggle, no menu item and no third party tool an owner should be using on a pack that runs at several hundred volts. A failed or partial flash can leave the car unable to charge at all.

The cost side should be zero. MG's own Windsor EV page states the battery warranty is lifetime for the first owner, and the car is sold from ₹14,84,800 ex-showroom, or from ₹9.99 lakh plus ₹4.3 to ₹4.6 per km under the battery subscription plan. A software update on the pack and its controller falls on the maker's side of that line. Get it in writing anyway.

What an owner can do

Before the workshop visit, build a record. Note the charger network, the location, the state of charge, the time and the exact error shown on the charger and in the app, and photograph both. Try a second charger on a different network, because that is the quickest way to separate a car fault from a charger fault.

At the service centre, ask for the BMS and high voltage battery software update by name. Ask for the software version before and after to be written on the job card, along with "no charge, under warranty". If the fault returns after the update, as that one forum owner reports it did, take it back on the same complaint number so the history stays linked, then escalate in writing to MG India customer care. If that stalls, the National Consumer Helpline and then the district consumer commission are the next steps.

Windsor owners in the club: did the BMS update hold at public chargers, or did the session still drop?

Sources

• MG Windsor EV DC Fast-Charging Issue: BMS Update Fix at Service Centers, EV India
• DC Fast Charging Issues with MG Windsor EV? MG Has You Covered, EVFY
• MG Windsor EV official page, JSW MG Motor India
• Owner thread on the Windsor Pro, EV Electree forum