[DeKay]

Originally Posted by pgsagar

I bought a Nexon EV facelift recently and I have a few queries. It's my first EV and I'm a bit clueless about EV physics.

1. Higher the speed, louder the whine. Is that whine normal? Does anything heat up during the regen-induced (3rd level) slowing down process from higher speeds like, say 100, as the current flow reverses from battery to wheel to wheel to battery.

2. This is also my first car with electric (or electronic, I'm not sure which) parking brake (EPB). There is also a P button on right side of shift-lever. Now, after stopping and shifting to N, should we engage this P button first or EPB. Similarly, to drive away, which one do we disengage first, EPB or P? What I've been doing is engage/disengage only the EPB and P just follows EPB.

3. Signal stops in my town are of short duration so instead of shifting to N, I have my foot on brake while car sits in D. Will anything wear out? It's not an automatic transmission, after all. It's just a one-gear car.

4. Sitting in parked car with "engine" on (or "Ready", as the panel says), can I have aircon on for an hour or more? Will it drain the 12v battery? And what charges the 12v battery? Main Battery or wheels, while in motion?

Can long-term EV owners enlighten me please? Any insight into these will really be appreciated.
Thanks.

1. Yes, absolutely normal. No, nothing heats up, use whichever setting you like the most, give it a couple weeks, drive it in all settings under various conditions and pick your poison.

2. What you've been doing is fine as long as that suits your instincts. The car doesn't care

3. Your car has Auto hold, does it not? Simply press the auto hold button that's around your EPB. As soon as you come to a stop at a red light and as long as you have auto hold enabled, you don't need to shift to D or P. Simply take your foot off all pedals and the car will hold position. The moment you press the accelerator, the auto hold will disengage itself on its own and you can drive off as you would normally.

4. You can sit in the car with its AC turned on for as long as your heart desires. There's a convertor that charges your 12V battery through the car's High voltage battery energy.

[pgsagar]

Originally Posted by DeKay

3. Your car has Auto hold, does it not? Simply press the auto hold button that's around your EPB. As soon as you come to a stop at a red light and as long as you have auto hold enabled, you don't need to shift to D or P. Simply take your foot off all pedals and the car will hold position. The moment you press the accelerator, the auto hold will disengage itself on its own and you can drive off as you would normally.

Thanks a lot, DeKay! You've been a great help.

Yes, my car has an Auto-Hold button right next to EPB. Will give it a try. The only reason I didn't try it was because I feared electronics acting up. If I had a way of A La Carte picking, I would have even picked a non-EPB variant with long range battery plus cruise control. But these things come bundled together, as a package.

[400notout]

So two breakdowns within 6 months of purchase! Odo stands at 6042 kms. Issue seems similar to the one before.









This time the difference being at least I can set the gearbox to neutral. A usual office commute ends up in exploring a new service centre

[400notout]

Originally Posted by 400notout

So two breakdowns within 6 months of purchase! Odo stands at 6042 kms. Issue seems similar to the one before.

Update:

The car was towed to the newly opened Trident motors kurla. As per the service advisor the issue was fixed by reflashing the software. The car is back on road and it was with the service centre for around 3 hrs including a trial run. The speed and diligence with which the Trident staff dealt with the issue is highly commendable. They immediately attended to a breakdown vehicle despite a huge prebooked lot, that too on a car which was not sold by them to begin with. Immediately created a whatsapp group with the CRM and RM in it and was updated realtime. 9/10 for that.

However I don't understand that how the software can suddenly brick out an otherwise smoothly running vehicle. If there are any experts out there please help me in understanding how this works and if it is avoidable. To give some context let me describe the events leading to breakdown.

It was an early morning commute and I had reached the Santa Cruz end of the Santacruz chembur link road. Since the road had stop and go traffic along with upward and downward gradations I had turned on the Auto hold function. When I was about to descent the final few meters of the flyover there was a jerk and the above warnings came up. I quickly pressed the brakes and noticed the acceleration was still on as it was being indicated on the left dial. I quickly put the gear in neutral after which the acceleration stopped. I slowly released the brakes and took the vehicle to a safe place where traffic would not be obstructed. I switched the car on and off a few times to see if it resolves the issue. It didn't and then I called up the RSA. Towing vehicle arrived in an hour and took me to nearest workshop (Trident). Thankfully this time the vehicle could be put in neutral which helped since the towing vehicle was not a flatbed.

Now this issue has occurred 2nd time within 5 months and 5k kms. I'm not sure how to go about this now. Any advice would be helpful.

[ferrarirules]

Originally Posted by 400notout

It was an early morning commute and I had reached the Santa Cruz end of the Santacruz chembur link road. Since the road had stop and go traffic along with upward and downward gradations I had turned on the Auto hold function. When I was about to descent the final few meters of the flyover there was a jerk and the above warnings came up.

Do you usually keep the auto hold function off? If yes, can you drive with it on most of the time and see if the issue resurfaces?

This may help in isolating the issue.

[Venky03]

Originally Posted by 400notout

Update

Now this issue has occurred 2nd time within 5 months and 5k kms. I'm not sure how to go about this now. Any advice would be helpful.

Was the brake pedal hard after the error occurred? I don't think this issue is related to usage of hill hold because I faced the same set of issues on my Nexon.EV MR which doesn't have EPB and hill hold.

[400notout]

Originally Posted by ferrarirules

Do you usually keep the auto hold function off? If yes, can you drive with it on most of the time and see if the issue resurfaces?

This may help in isolating the issue.

I keep it off most of the time. I usually turn it on at signals or when I'm halted at a gradient to avoid rolling back. Once when I was stuck in a jam for a longer period, the Auto hold function turned off and the vehicle switched to the parking brake on its own. However when I got moving all worked as it should.

Originally Posted by Venky03

Was the brake pedal hard after the error occurred? I don't think this issue is related to usage of hill hold because I faced the same set of issues on my Nexon.EV MR which doesn't have EPB and hill hold.

You could say it was hard, but it did work. I'm not sure now if its a hardware issue, cause if it is, how does a software flash resolve it?

[electric_eel]

Originally Posted by pgsagar

Thanks a lot, DeKay! You've been a great help.

Yes, my car has an Auto-Hold button right next to EPB. Will give it a try. The only reason I didn't try it was because I feared electronics acting up. If I had a way of A La Carte picking, I would have even picked a non-EPB variant with long range battery plus cruise control. But these things come bundled together, as a package.

Although I too am skeptical of EPBs (I prefer the good old parking brake), auto hold is one feature I have grown to like, so also my better half. Both of us drive our Nexon EV Max with auto hold on and never keep it off. When moving out of very steep slopes, there is a small backward movement (not much but not to my liking) . So I pull the EPB too in addition. Pressing the throttle releases both so no issues there.

[400notout]

Originally Posted by Venky03

I don't think this issue is related to usage of hill hold because I faced the same set of issues on my Nexon.EV MR which doesn't have EPB and hill hold.

Could you elaborate on the issues you faced? Any idea how the SC managed to fix it? I'm planning to put an email to the regional head of EV any info would help.

[Venky03]

Originally Posted by 400notout

Could you elaborate on the issues you faced? Any idea how the SC managed to fix it? I'm planning to put an email to the regional head of EV any info would help.

I had attached the dashcam footage to my post, it happened in middle of the traffic and my brake pedal was totally hard. The car was not ready to shift from D to N, and when I did a restart it was not ready to shift to D. Service team gave the same reflashed software reply.

[pgsagar]

I have a few technical questions on EVs.

1. LFP batteries are said to be good for 3,000 to 10,000 charge cycles. Now, one can charge from almost 0% to 100% or even from 50% to 100% (or any combination). If I charge from say 50% to 80%, will it also be considered one charge cycle? If so, then it's better to charge from close to 0% to 100% to maximize logged KMs. Right? Any inputs on this please.

2. My Nexon LR came with a 7.2 KW charger thrown in gratis by Tata. Additionally, there is a 3.3 KW portable cable +gun in trunk. I want to set it up, too, in my parking spot, right next to 7.2 one. As standby/for trickle charge. Now, is it ok to buy an ordinary 16 amp 3-pin socket from an electrical store? Or, do I need a branded socket? I don't want to buy those big metal box ones, like Tata's Ziptron/ Legrand etc as these are pricey and I don't want to spend much on standby set-up. And, what should be the amperage of MCB?

3. Yesterday, after getting into car and slotting into D, I pressed throttle. The car behaved like it was struggling to climb over a brick placed under the wheel. I thought there was probably a rock under the wheel. I put car in R and pressed throttle. Same result. I was puzzled. I was about to get out of car to check and then I noticed that I forgot to disengage Electric Parking Brake. I did that and drove off. All normal. Now, could this have caused any damage to EPB system? I wish they had a warning chime.

4. The accessory guy at Tata dealer was suggesting seat covers on fabric seats of my Fearless Plus LR variant. Now, the car has 6 airbags. The dealer says new seat covers are Tata-approved and they have openings for airbag deployment. Is it true? Is it ok to go for them?

[electric_eel]

Originally Posted by pgsagar

I have a few technical questions on EVs.

1. LFP batteries are said to be good for 3,000 to 10,000 charge cycles. Now, one can charge from almost 0% to 100% or even from 50% to 100% (or any combination). If I charge from say 50% to 80%, will it also be considered one charge cycle? If so, then it's better to charge from close to 0% to 100% to maximize logged KMs. Right? Any inputs on this please.

My suggestion is not to get worked up on the charge cycle. Most battery packs will last much more than the car with almost no degradation. The more serious issue with LFP batteries (at least in Tatas) is the BMS getting the SoC wrong. This happens because the voltage vs SoC of LFPs are nearly flat for most of the operational region and hence it is difficult for BMS to look at the voltage and guess what is the SoC.

So try to charge to 100% (slow charging) every single time. Again you do not have to increase your blood pressure if you did not do it once or twice.

As to how low one should take the battery SoC. opinions wary. I wait till I get to below 20 to charge (again not always but most of the time). It is also suggested that you get the SoC below 10% once in a while. but practical considerations make this really difficult. The car goes into tortoise mode and then it is a pain to drive especially if you are on a highway. As such I have done it only a few number of times in my close to 1.5 years of ownership.

[Shreyans_Jain]

Originally Posted by pgsagar

I have a few technical questions on EVs.

1. LFP batteries are said to be good for 3,000 to 10,000 charge cycles. Now, one can charge from almost 0% to 100% or even from 50% to 100% (or any combination). If I charge from say 50% to 80%, will it also be considered one charge cycle? If so, then it's better to charge from close to 0% to 100% to maximize logged KMs. Right? Any inputs on this please.

2. My Nexon LR came with a 7.2 KW charger thrown in gratis by Tata. Additionally, there is a 3.3 KW portable cable +gun in trunk. I want to set it up, too, in my parking spot, right next to 7.2 one. As standby/for trickle charge. Now, is it ok to buy an ordinary 16 amp 3-pin socket from an electrical store? Or, do I need a branded socket? I don't want to buy those big metal box ones, like Tata's Ziptron/ Legrand etc as these are pricey and I don't want to spend much on standby set-up. And, what should be the amperage of MCB?

3. Yesterday, after getting into car and slotting into D, I pressed throttle. The car behaved like it was struggling to climb over a brick placed under the wheel. I thought there was probably a rock under the wheel. I put car in R and pressed throttle. Same result. I was puzzled. I was about to get out of car to check and then I noticed that I forgot to disengage Electric Parking Brake. I did that and drove off. All normal. Now, could this have caused any damage to EPB system? I wish they had a warning chime.

4. The accessory guy at Tata dealer was suggesting seat covers on fabric seats of my Fearless Plus LR variant. Now, the car has 6 airbags. The dealer says new seat covers are Tata-approved and they have openings for airbag deployment. Is it true? Is it ok to go for them?

1. With LFP batteries, I would not be worried about number of charge cycles.

2. You can charge using any regular 16 amp 3 pin socket. Charging will work as long as the point has proper earthing.

3. The electronic parking brake will auto disengage if the driver is wearing seatbelt and accelerator is pressed in D or R. If seatbelt is not fastened, EPB will have to be manually disengaged.

4. Aftermarket seat covers in a car with 6 airbags is always a grey area. Better to take official confirmation from Tata using Twitter.

[pgsagar]

Originally Posted by Shreyans_Jain

1. With LFP batteries, I would not be worried about number of charge cycles.

2. You can charge using any regular 16 amp 3 pin socket. Charging will work as long as the point has proper earthing.

3. The electronic parking brake will auto disengage if the driver is wearing seatbelt and accelerator is pressed in D or R. If seatbelt is not fastened, EPB will have to be manually disengaged.

4. Aftermarket seat covers in a car with 6 airbags is always a grey area. Better to take official confirmation from Tata using Twitter.

Thanks a lot for clearing things up, S. Jain.

E_eel, hell no, I'm not at all worried about battery life nor is my BP up, if that's what you think. I asked for pure academic interest. My annual running is just 5,000 km. For my heavy-pedal driving, even if I take very conservative estimate of 200 Kms on full charge, 3000 charge cycles translate to 6 lakh KMs. Given my 5000 km annual run, battery may last 120 years. Both I and car will be long gone from this planet by then.

[wocanak]

Originally Posted by pgsagar

E_eel, hell no, I'm not at all worried about battery life nor is my BP up, if that's what you think. I asked for pure academic interest. My annual running is just 5,000 km. For my heavy-pedal driving, even if I take very conservative estimate of 200 Kms on full charge, 3000 charge cycles translate to 6 lakh KMs. Given my 5000 km annual run, battery may last 120 years. Both I and car will be long gone from this planet by then.

The reported cycles are equivalent full cycles, i.e. if you do 50% charging four times, it will be considered 2 cycles (irrespective of what you started and ended in)

When charging, keep it simple and go by what is given in the manual. In simple terms, charge when it goes below 25% (SoC% indicator turns orange) and charge up to 100%. Once a month make it go down to 10%. For every 4 fast charging, do one slow charge to 100%. This covers most of it.

It is not required to strictly follow this all the time, you can break this once in a while, just do it mostly.