[navinmra]

With the 15,000 KM mark coming up for my Nexon EV Max in around 10 months, I wanted to find out if the battery had degraded, and if so by how much. I have heard on some forums that Tesla batteries degrade by 1% per year so that fueled my curiosity.

On a recent journey from Bangalore to Manipal, I used data from the dashboard and the mid point fast charger to arrive at the battery capacity (and therefore the degradation) It is crude but I want to share with you all to see if you had any reactions:

1. I started with 100% charge.
2. At 49% SOC, I charged to 86% on a Zeon DC fast charger (pic attached)
3. I reached my destination with 29% SOC after clocking 414.9 KM (pic attached
4. My efficiency for the trip was 105 Wh/km

Now the calculation:
1. Total energy consumed on the trip = 105 Wh/Km X 414.9 km = 43.564 KWh
2. In terms of SOC % total energy consumed = 51% + (86% - 29%) = 108%
3. Therefore 100% capacity = 43.564/1.08 = 40.337 KWh

Now, we know that the Nexon EV Max battery capacity is 40.5 KWh. Therefore a capacity of 40.337 KWh translates to 99.59%

Therefore I am concluding that my battery has degraded by 0.41% after 15,000 Km and nearly 10 months. Which personally is quite impressive.

I know this is very crude back of the envelope calculation and does not take into count residual battery capacity (not all capacity is made available to tap into) etc, but hopefully that triggers some thoughts amongst you all…

[mally2]

Interesting way. Or you can ask the TASS to check the SoH on the next service schedule. I did mine for the tiago.ev @ 15k kms and the SoH was 99%. Since there is no further decimal I had to assume that the degradation is around 1% or less. There are others in the tiago community who have done 25-30k kms and it’s still at 99%

[navinmra]

Thanks @mally2. Great to see your battery stats. So it does look like the batteries are living up to the promise of durability. Perhaps that explains TaMo (and the broader industry) confidence in their 8 yr / 1,60,000 km warranty.

[TorqueAddict007]

Originally Posted by mally2

Interesting way. Or you can ask the TASS to check the SoH on the next service schedule. I did mine for the tiago.ev @ 15k kms and the SoH was 99%. Since there is no further decimal I had to assume that the degradation is around 1% or less. There are others in the tiago community who have done 25-30k kms and it’s still at 99%

Thank you, posts like yours really give me all the confidence I need to completely be at ease with my decision to buy the Punch EV. Battery degradation and the cost of replacement after the warranty period is the biggest concern for anyone who buys the EV but I guess if batteries are this durable, then end of warranty period need not result in a complete battery replacement. I plan on keeping the car until at least 2030, and this gives me a great deal of confidence.

[mally2]

Originally Posted by navinmra

Thanks @mally2. Great to see your battery stats. So it does look like the batteries are living up to the promise of durability. Perhaps that explains TaMo (and the broader industry) confidence in their 8 yr / 1,60,000 km warranty.

Oh the batteries are definitely gonna outlast the vehicle easily and most certainly find a second life as solar back ups or other industrial uses.

[navinmra]

Absolutely true. The battery will outlast the car. Let’s say in 10 years, your battery degradation is 10%. In real world terms it means that the range, say for my Nexon will be 270 km instead of 300 km. I still charge every 200 km on long drives so there is no change for me whatsoever.
Lastly, as more charging stations come up, wherever little range anxiety is there will also go away.

[shortbread]

Thank you navinmra. Some of the ludicrous theories revolving around electric involves ones such as taking into account the battery price which one has to replace. Do we take into account the price of a new petrol engine when one buys an ICE car? The batteries will outlast the vehicle, let alone the 5-7 year period within which most people replace their cars.

[soarersc300]

Originally Posted by shortbread

Thank you navinmra. Some of the ludicrous theories revolving around electric involves ones such as taking into account the battery price which one has to replace. Do we take into account the price of a new petrol engine when one buys an ICE car? The batteries will outlast the vehicle, let alone the 5-7 year period within which most people replace their cars.

The concern also is the rapidly advancing technology making today's EV redundant in 10 years. Take today's Tata EVs which cost around 15 lacs and take an hour to charge fully. Just a few ears from now we will have same Tata EVs charging fully in 10 minutes and also provide double the range. So in 10 years time when an average mass market EV gives 600km + range and charge time of 10 minutes it will look prehistoric to drive a car with 250km range taking an hour to charge. The resale value will be practically 0.

[shortbread]

Originally Posted by soarersc300

The concern also is the rapidly advancing technology making today's EV redundant in 10 years. Take today's Tata EVs which cost around 15 lacs and take an hour to charge fully. Just a few ears from now we will have same Tata EVs charging fully in 10 minutes and also provide double the range. So in 10 years time when an average mass market EV gives 600km + range and charge time of 10 minutes it will look prehistoric to drive a car with 250km range taking an hour to charge. The resale value will be practically 0.

Isn't that the case with ICE as well, modern cars are far more powerful, safer, efficient, feature packed etc.... do the old cars come free?

Plus once regulations become tougher, it's more likely that today's ICE cars won't be road legal in 10 years time. Main cities will start with the ban of diesel, followed by petrol, more likely that used EVs might be the popular fall back option.

[Redex]

Many "degraded" batteries are actually down to the way the user charges the battery, especially in earlier models. The early software was not based on endless "top ups" but engineers assumed that users would drive until nearly empty then do a full recharge. Try, fully charging the vehicle then park it up off road, leave the heater and air con running until the system shuts down. Recharge and repeat. Then recharge and check the SOH. Slow charging whenever possible helps.
This is simple non technical advice, not going to get into the realms of battery repair.
Regards Neil
IMI Level 4 Diagnostics and Repair Qualification.

[careind]

Originally Posted by navinmra

Therefore I am concluding that my battery has degraded by 0.41% after 15,000 Km and nearly 10 months. Which personally is quite impressive.

A novel idea indeed!
I think you can use the same model and track the data at different timepoints ( in the future ) so that you can have better insight into whether the deterioration happens linearly.
I doubt that the degradation would progress faster with the age of the battery and would be a curve and not a straight line.

Any of the early adopters can chime in based on the same formula which could also give (rough) insights into the rate of deterioration with the caveat that “Not all batteries age alike”, but would give a decent idea.

[Hume]

Originally Posted by shortbread

Isn't that the case with ICE as well, modern cars are far more powerful, safer, efficient, feature packed etc.... do the old cars come free?

Plus once regulations become tougher, it's more likely that today's ICE cars won't be road legal in 10 years time. Main cities will start with the ban of diesel, followed by petrol, more likely that used EVs might be the popular fall back option.

I think there's some merit to the opposing argument, TBH.

The tipping point for what you are saying is still to come - perhaps 10+ years down the line at least in India, when you have to start fearing bans, legislations and what not (And you'll still be given adequate time after such laws come into effect). Until then, as things stand, purely in terms of resale values due to technological advances and overall for items related to battery replacements, warranties and insurance covers, uncertainty and ambiguity exists with some testimonies of battery and insurance issues already existing.

Also, Engine vs battery replacement is not exactly the same - neither in cost or how easy it is to replace parts of each, at least for now. Say for a 50 Lakh vehicle whose battery might cost upwards of 20-25 lakhs (40-50%) now, if anything were to happen after the warranty period of 8 years and a replacement is necessary (since most manufacturers don't yet wish to tinker with battery packs for safety reasons and suggest replacing the pack itself), then for what could be a 10 lakh value attributed to the same car after 8 years, the battery itself might be around 10-15 lakh). So for some who might wish to keep cars for a longer time with some peace of mind, this might then not necessarily give the required comfort.

I for one am very excited about the inherent advantages of an EV - especially the drive - and might be willing to overlook that risk. But it's not for everyone and I can understand if others might see things a little differently. I am aware that thing will evolve and more clarity will emerge with time and hopefully, all such concerns will be laid to rest. But for now, it's not very black and white. Just saying...

[Ray379]

I had done something similar to what @navimra has done on my Tigor EV at 35000kms. Found that it was about 1% lesser than when I had done a similar calculation at 5000km when the AC had given issues. Then it was exactly the no of kms it should run according to the wh/km shown on the dash.

Did not know that TASS actually has a way to calculate and share a battery health report. Would certainly get on at the 40000km service check. Thank you for the information.

[josetom89]

Slightly off topic, but do the energy consumption increase when the weather is hot? Say 38-40 degrees.
I have noticed that my average consumption has increased to 120-130 wh/km from 110-120.
Or could it be due to the fact that I changed tyres to a normal one rather than low rolling friction tyre.
Mine is a Tiago EV.

[mally2]

Originally Posted by josetom89

Slightly off topic, but do the energy consumption increase when the weather is hot? Say 38-40 degrees.
I have noticed that my average consumption has increased to 120-130 wh/km from 110-120.
Or could it be due to the fact that I changed tyres to a normal one rather than low rolling friction tyre.
Mine is a Tiago EV.

Yes sir, quite normal, as the AC uses more energy to cool cabin and keep battery in optimal temperature