Battery life and replacement cost

Hi all, premptative question, anyone aware of the life expectancy of the battery pack. I believe we have a manufacturers warranty of 80k miles but unsure when deterioration gets so bad a replacement is needed.

Reason for the enquiry is the pooŕ resale value, it appears I'll be hanging onto my ZS far longer than anticipated given I'm at 30k after 20mths.

Also any ideas on cost would be helpful

You will find if you follow the advice on looking after the battery (20% to 80% most of the time with 100% as and when needed to balance the cells), the battery will probably out last the structural integrity of the car.

In January, my son bought a 2014 LEAF and the battery was at 84%, which for a 9 year old EV with no active thermal management is good going.

As to cost, the battery is the most expensive part of the car. If you do a search, it'll probably give you the price of new and second hand.

Interesting, thanks, how would I get the current state of the battery condition, request during annual service?

It seems like the evidence from high mileage users (taxis and the like) of EVs shows battery life isn't a problem. As GG says, the battery will not be the part that determines the life of the car.

Even if there is a problem (due to poor charging practices maybe) battery costs are coming down all the time as production ramps up, so will be less of an issue in the future I suspect.

Radders said:

Interesting, thanks, how would I get the current state of the battery condition, request during annual service?

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The dealership should be able to give you a battery health report, or get an OBD2 dongle which plugs into the car and a phone app to access some of the car's stats. That's how I checked the LEAF battery before my son bought it.

There are a few threads about OBD2 dongles on here if you do a search.

Radders said:

Hi all, premptative question, anyone aware of the life expectancy of the battery pack. I believe we have a manufacturers warranty of 80k miles but unsure when deterioration gets so bad a replacement is needed.

Reason for the enquiry is the pooŕ resale value, it appears I'll be hanging onto my ZS far longer than anticipated given I'm at 30k after 20mths.

Also any ideas on cost would be helpful

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We've just sold our Outlander PHEV, 2015 model with 165,000 on the clock, the battery was absolutely fine. Remember, the manufacturers of the cells term them end of life when their capacity drops to 80%, they dont suddenly die in most cases, you would notice a drop off in range. My i3 has 85,000 miles and no recognisable deterioration.

Dont worry about it.

Feel better for that! Still would have preffered to replace after two years but ain't giving it away.

Radders said:

Hi all, premptative question, anyone aware of the life expectancy of the battery pack. I believe we have a manufacturers warranty of 80k miles but unsure when deterioration gets so bad a replacement is needed.

Reason for the enquiry is the pooŕ resale value, it appears I'll be hanging onto my ZS far longer than anticipated given I'm at 30k after 20mths.

Also any ideas on cost would be helpful

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The MG battery has unusable buffers at top & bottom of state of charge and active thermal management. Both are a good thing for battery life.
Our 10 year old leaf gets charged to 100% every night and has no thermal management. It still has about 80% SOH. Our 10 year old Volt has larger buffers and thermal management and has no discernible loss of SOH.
The rest of your MG will wear out before the battery does. Nobody knows how much a battery pack costs to replace because nobody has had to do it.

Good enough for me

Even if you were unlucky enough to experience a serious problem with your traction battery, this does not mean the whole pack is totally US / condemned.
The pack could be removed, stripped and any faulty cells identified in a single battery rack, and then could be replaced.
Whole packs are never completely and utterly scrapped off !.
Entire battery pack replacement is pretty rare.
If this WAS to happen under warranty, then it is likely you would receive a recon’s unit !.
Water / flood damaged EV’s are not great news.
Deep flood water ingress, that enters into EV battery, is a very bad combination.
The pack and likely the car, is likely to be totally destroyed in this type of situations.
There are numerous case studies that suggest that the battery pack will outlast the life of the car TBH.
Some EV’s have covered star ship mileage and are still going strong.
I would not be overly concerned myself.
There will be a slight loss in range over the years, purely due to a little battery degradation.
In this respect, it is similar to ICE powered cars.
As time moves on engines develops more and more wear, therefore the MPG ( range ) slowly reduces as wear in the engine etc increases over time.
So, it’s not just an EV thing.

Our 2 year-old MK1 ZS EV was at 100% SOH at the first service but just has its second service and the SOH had dropped by 6%, to 94%. I was astonished by the drop in a single year as although the car is used daily it is low mileage and the battery is never run low or fast charged. We usually charge it from about 25 to 33% and it is on charge long enough to balance the cells. I get a charge rate graph in the charger app, so can see that balancing is taking place.

From what I can see from the warranty docs the guarantee kicks in once battery capacity goes below 70%. NB they only guarantee to get you back to 70% (although that seems unlikely as they'd only get another claim shortly after).

Radders said:

Hi all, premptative question, anyone aware of the life expectancy of the battery pack. I believe we have a manufacturers warranty of 80k miles but unsure when deterioration gets so bad a replacement is needed.

Reason for the enquiry is the pooŕ resale value, it appears I'll be hanging onto my ZS far longer than anticipated given I'm at 30k after 20mths.

Also any ideas on cost would be helpful

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4000 full (0-100%) charge cycles is about right for a thermally managed traction pack, so at 3.8 miles per kWh (235 miles for 62kwh pack) that’s 940,000 miles battery life. A drop in capacity will probably happen a bit before this but still even at 2,000 charge cycles you’re looking at 470,000 miles. Don’t worry about the charging to 100% as this won’t affect the number of complete charge cycles it will just mean the battery will last longer in time which suits the warranty better. The battery management system doesn’t allow full discharge or maximum cell charge voltage, the 100% indicates the allowed usable capacity , it’s set up very conservatively with a large low and high voltage buffer to help fast charging and discharging. All charge speeds slow to the exact same rate towards the last 10-5% from 140kw rapid to 2.2kw 10amp house hold socket.

Hi. I’ve had my MG5 short range for 1.5 years now. I’m a taxi driver and I charge my car at home to 100% most days. About once a week I have to use a rapid charge and usually only charge to 80-85% lwhenni do.

I have done 45k and did my last service at 43k. The battery was at 99% at last service, but have not really noticed any dramatic change in range.

Very happy. Just bought the wife one as she was shocked at what I was earning and now has decided to become a Taxi driver. She was a school teacher.

p1xelman said:

Our 2 year-old MK1 ZS EV was at 100% SOH at the first service but just has its second service and the SOH had dropped by 6%, to 94%. I was astonished by the drop in a single year as although the car is used daily it is low mileage and the battery is never run low or fast charged. We usually charge it from about 25 to 33% and it is on charge long enough to balance the cells. I get a charge rate graph in the charger app, so can see that balancing is taking place.

From what I can see from the warranty docs the guarantee kicks in once battery capacity goes below 70%. NB they only guarantee to get you back to 70% (although that seems unlikely as they'd only get another claim shortly after).

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That doesn’t indicated a loss of capacity as it’s well within the nominal capacity from manufacture. If you 0-100% capacity test it you will find it is actually over what the manufactures state. My 64kwh usable capacity is 61.8 but on testing (minus some losses) it comes in at 62.6kwh. A few rapid charges can push the SOH up a bit, lithium traction packs like to be charged and discharged often and even at MGs top 140kw rate it’s no where near what the pack could potentially handle.

In short don’t worry it has a very generous warranty and is set up to last a long time with minimal chances of failure, unlike an internal combustion engine with 10,000 parts and 1000 moving parts where a cam belt can cause a few thousand £ worth of damage with (hardly) any warning.

Ok this is a smaller pack and actually a bit older tech compared to the current ev battery packs but a good explanation.

i know this is an old thread ,but as i needed to know the price of the battery for depreciation for my tax return , I had a bit of a shock . I was told that the battery comes only as a whole package , and the price is €34,400 , and that assuming you need to get charged for the removal and refitting of the battery which would be probably around another 1k + .

nexia201 said:

i know this is an old thread ,but as i needed to know the price of the battery for depreciation for my tax return , I had a bit of a shock . I was told that the battery comes only as a whole package , and the price is €34,400 , and that assuming you need to get charged for the removal and refitting of the battery which would be probably around another 1k + .

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Really, that sounds odd as surely the car as a whole is used to determine future values and depreciation, after all you wouldn’t separate the motor and charger. As someone who builds batteries from salvaged ev packs I’d ignore any reference to new replacement packs as you can get a complete low mileage used pack from an ev dismantling salvage yard for £4-6,000, plus the faulty pack will be worth a few thousand £ too. So the depreciation of the battery in the car would be difficult to determine, if you take it out and sell it you would get around £5,000ish so if it cost £7,000ish to manufacture you have a couple of thousand depreciation, this would be worth less after say 10 years, 10year old Nissan Leaf packs sell for around £2,500. Best though if out of warranty is to repair the existing pack. Last time I researched replacement battery pack price for various vehicles these high £30k plus reported claims were unfounded, I mean manufacturing for a pack is around $120 per kWh for the legacy brands and under $100 for the better supplied brands such as MG.

I think this is why it is good practice to use the 20%-80% rule if you own the vehicle. When you come to sell the vehicle, the buyer can easily plug in an OBDII scanner and check the battery health. I did this when my son bought a 9 year old LEAF. The battery was 84% SOH, which was fine for that age LEAF.

Obviously if you are leasing, then none of this matters.

I was at an MG dealer a couple of weeks ago. The service manager showed me a quote for a replacement battery pack. The car it was for was identical to my Mk1 (he said he did a double take when I went in as the reg is very close too) that had been water damaged by sitting in a shallow flood for 3 days. No water had entered the car but the pack was destroyed. The battery pack was £24,000 and it only needed one hour of labour to swap.

WHAT? That’s what I paid for the new car!

chris69 said:

I was at an MG dealer a couple of weeks ago. The service manager showed me a quote for a replacement battery pack. The car it was for was identical to my Mk1 (he said he did a double take when I went in as the reg is very close too) that had been water damaged by sitting in a shallow flood for 3 days. No water had entered the car but the pack was destroyed. The battery pack was £24,000 and it only needed one hour of labour to swap.

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what no insurance right off ????