My Tata Nexon EV: Sudden drop in charge level leads to a breakdown

My dad was driving the car and when the vehicle was taken out of my building it had a charge of 53% remaining.

BHPian turbotechnixxx recently shared this with other enthusiasts.

Hello,

I have using a NEXON EV Zx+ Prime since September 2022 and I'm more than happy with the car. However, recently a very strange problem occurred in my vehicle. My dad was driving the car and when the vehicle was taken out of my building it had a charge of 53% remaining. Not worrying about it, my dad took the vehicle out since he had to merely travel for about 55kms tops. However, on his way back he saw the battery charge percentage at 35% which in just 2 kms dropped to 0% and the vehicle stalled in the middle of the road. We called the TATA helpline and was genuinely impressed by the way how a flatbed tow truck arrived in less than 40 mins at my location to pick up the car and drop it to an authorized service station. As per the protocol the ASC is supposed to charge the vehicle fully and discharge it fully to see if there is an issue in the battery. They ran the tests and the battery just worked fine. They have updated the software and have sent the car back. Has anyone else faced a similar issue?

Here's what BHPian DRPSREDDY had to say on the matter:

Just go to the Electric Cars section of this forum and check the NEXON EV thread. Two customers had similar complaints and the service centre did the same for them. Eventually they came back with similar complaints and the Company called in experts and the company replaced the battery pack under warranty.

So, looks like you too need a battery pack replacement.

Here's what BHPuan ferrarirules had to say on the matter:

I have a few questions:

• Was this sudden discharge visible in the zconnect app?. Can you please share your monthly charging graph?
• Did your father try locking the car, walking away and trying to start the car again after few mins?

BHPian Turbotechnixxx replied:

While the Zconnect app showed 2% of charge, it was actually zero on the dash.

Yes, he tried switching off the car (without locking it though) and turned it on several times but it didn't work.. What is worth pondering over is that the power windows refused to operate at one point and 2 windows remained open for sometime (Power Windows work on 12V). 5 minutes later both the windows were operational.

Here's what BHPian prasanna_indaje had to say on the matter:

What you said indicates presence of few bad cells in your HV battery pack. This issue is likely to reoccur at similar percentage of SoC, and will drain to 0% in no time. However, the car would be functioning normally on higher state of charge.

For example : Perfectly working till 35% SoC and then dischagre to 0% within 2 kms. On slow charging, SoC will reach to 35% (from 0%) within few minutes and thereafter charge at normal speed till 100%.

Please monitor this behavior for on more occurrence (try near home or charging point) take screenshots of discharging and charging pattern and raise case with TASS. If you can reach out to EV service manager from Tata Motors for the region, even better.

My Nexon EV had similar issue and HV battery pack was replaced by TaMo.

Here's what BHPian Nanolover had to say on the matter:

Battery replacement is imminent. This was the same case for my tigor ev. They first took it "updated" the software and within 10 kms car was stuck once again in the middle of the road. Escalated via team bhp and my personal contacts and entire battery pack was replaced which took 2 weeks.

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