i8 purchase and battery question
Discussion
Hi, thought i would try here rather than the BMW section.
I am hopefully about to purchase an i8. It is a 2015 model with very low miles so in 3 years the battery warranty will expire before the mileage limit.
Does anybody have any idea what this might mean for us owners?
Does anyone have any idea on battery retardation/failure on the very earliest cars?
Thanks in advance
I am hopefully about to purchase an i8. It is a 2015 model with very low miles so in 3 years the battery warranty will expire before the mileage limit.
Does anybody have any idea what this might mean for us owners?
Does anyone have any idea on battery retardation/failure on the very earliest cars?
Thanks in advance
Dont know about the i8 specifically, but the i3 had a few gremlins in the early 2013/4 models, but all got fixed quickly and the reputation of the 2015 and later models is actually pretty good. Batteries are solid and while they might be different to the i8, the i3 doesnt seem to suffer any major issues. Reliability issues in the i3 are focused on other stuff - sticking filler covers, glitchy software for the lane controls, oil leaks for the Rex and heavy tire wear in certain situations. That doesnt mean that the battery doesnt have issues, it does seem rare with the i3.
There is a test on the i3 to check though - not sure if it works for the i8:
https://www.youtube.com/watch?v=dIP_lThJYWE
And i8 batteries are going for between $2k and $4k - not cheap, but accessible at the right price. So doable. Oh and have you seen Rich Rebuilds i8? He did some performance mods and is getting pretty impressive times out of his!
There is a test on the i3 to check though - not sure if it works for the i8:
https://www.youtube.com/watch?v=dIP_lThJYWE
And i8 batteries are going for between $2k and $4k - not cheap, but accessible at the right price. So doable. Oh and have you seen Rich Rebuilds i8? He did some performance mods and is getting pretty impressive times out of his!
There's an active i8 group on Facebook and a dedicated section on Bimmerpost both of which have more i8 traffic than here but whilst there have been other frequent glitches (fuel filler/door struts etc) batteries do not seem to feature
Given low use and lack of indies I'd be tempted for year one to take an official BMW warranty for about £ 1500 and let the car settle down at their expense
Given low use and lack of indies I'd be tempted for year one to take an official BMW warranty for about £ 1500 and let the car settle down at their expense
Edited by johnnyreggae on Tuesday 10th November 08:08
There are two scenarios to think about - a bricked battery and a battery thats losing some of its capacity.
Bricked is fairly rare but of course as they get older it could become more of a thing I guess - but see the point below
The capacity loss is also fairly light. The battery isn't the main driving force and the engine kicks in unless its happy for the battery to be used and this can only be a good thing for the battery so on the balance of probability its going to have an easeir time of things. So long as the battery has charge then from a spirited drive perspective it will still be giving shove whenits called upon. When we had one, and ours was an LCI so had a 50% bigger battery anyway, but in sport mode it never ran out however hard i drove it - the engine is constantly topping it up except on wide open throttle.
That leaves battery range - loss of capacity will knock off range, but on a pre LCI you're looking at maybe 15-20 miles rated and 2/3 that in practice. So a 10% drop is losing 1-2 miles. Not something I'd be especially worried about.
As time goes buy there are more garages/specialists who strip down and fix batteries. I've no idea how hard it is to get the batter out the i8 but assuming it doesn't come out through the cabin (its located in the centre tunnel I believe) then give it 3 years and a specialist will probably be offering to fix some dead cells for a relatively cheap money and may even be offering capacity upgrades.
The TD;DR - I wouldn't worry about the battery.
There are other things to think about with the i8 as it ages like a 3 cylinder engine having the life wrung out of it, a cooling system that is notoroiously hard to bleed, even the door struts that hold them open need to be regularily replaced. But if you can get in and out easily and are happy with the performance then they're a truly nicely place to be.
Bricked is fairly rare but of course as they get older it could become more of a thing I guess - but see the point below
The capacity loss is also fairly light. The battery isn't the main driving force and the engine kicks in unless its happy for the battery to be used and this can only be a good thing for the battery so on the balance of probability its going to have an easeir time of things. So long as the battery has charge then from a spirited drive perspective it will still be giving shove whenits called upon. When we had one, and ours was an LCI so had a 50% bigger battery anyway, but in sport mode it never ran out however hard i drove it - the engine is constantly topping it up except on wide open throttle.
That leaves battery range - loss of capacity will knock off range, but on a pre LCI you're looking at maybe 15-20 miles rated and 2/3 that in practice. So a 10% drop is losing 1-2 miles. Not something I'd be especially worried about.
As time goes buy there are more garages/specialists who strip down and fix batteries. I've no idea how hard it is to get the batter out the i8 but assuming it doesn't come out through the cabin (its located in the centre tunnel I believe) then give it 3 years and a specialist will probably be offering to fix some dead cells for a relatively cheap money and may even be offering capacity upgrades.
The TD;DR - I wouldn't worry about the battery.
There are other things to think about with the i8 as it ages like a 3 cylinder engine having the life wrung out of it, a cooling system that is notoroiously hard to bleed, even the door struts that hold them open need to be regularily replaced. But if you can get in and out easily and are happy with the performance then they're a truly nicely place to be.
I have a 2015 i8, Its just rolled over to 50,000 miles, and the car still feels and looks new, not a rattle.
It seems to have about 17 miles each time its unplugged, which isn't great, but good enough for what I use it for, popping to the shops in E-mode alone, finding a favourite bit of road, Sport mode can always get some more battery miles too.
I'm a member of that Facebook group, really helpful too!
https://www.facebook.com/groups/bmwi8group
There's also a chap called Pat, who has a YouTube channel about running/looking after his i8, which is a useful resource. He regularly posts on the Facebook group.
https://www.youtube.com/channel/UC0IIDwOyRGjykIkpH...
It seems to have about 17 miles each time its unplugged, which isn't great, but good enough for what I use it for, popping to the shops in E-mode alone, finding a favourite bit of road, Sport mode can always get some more battery miles too.
I'm a member of that Facebook group, really helpful too!
https://www.facebook.com/groups/bmwi8group
There's also a chap called Pat, who has a YouTube channel about running/looking after his i8, which is a useful resource. He regularly posts on the Facebook group.
https://www.youtube.com/channel/UC0IIDwOyRGjykIkpH...
Edited by jamesbilluk on Tuesday 10th November 17:33
Thank you so much for all your replies and the heads up on the Facebook group.
I have now bought the car so just collection to organise
It’s a 2015 car that’s done 3500 miles with a BMW warranty so let’s see what happens. Both i3’s I’ve run have been faultless.
I have been lusting after them for years and just thought f
k it, why not. I have other cars for other needs so my wife will take the i3s full time and this will be my daily...and I cannot wait.
I have now bought the car so just collection to organise

It’s a 2015 car that’s done 3500 miles with a BMW warranty so let’s see what happens. Both i3’s I’ve run have been faultless.
I have been lusting after them for years and just thought f
k it, why not. I have other cars for other needs so my wife will take the i3s full time and this will be my daily...and I cannot wait. FeelingLucky said:
The LCI model is usefully improved in key areas and 2 year old low mileage examples can be had for £58k before haggling, I wouldn't really say depreciation is anything other than horrific.
But I'd hope a 2014 would have done most of it's "off a cliff" depreciation by now.
Horrific depreciation is all but done now on all of them. If you bought an LCI for 58k I imagine you'll enjoy a slowish drift downwards. I just feel for the poor sod who bought it new,although BMW were doscounting them down to about 80k. We bought our LCI for 63k and sold it back to the dealer for 55k just under a year later (I'm the wrong shape and age to get in easily and the wife had a broken leg and it didn;t see that sensible to own) otherwise I loved it - but 8k drop in a shade under a year isn't bad especially if you factor in the dealer margin. I think my old one might be the one thats 58k if its a while one at Sytner. But I'd hope a 2014 would have done most of it's "off a cliff" depreciation by now.
I’d imagine £8k in year one is totally expected (dealer margin mostly) and then it would plateau a bit over the years.
I offered and paid £45k for 2015 Protonic Blue car with 3500 miles. It was up a few months ago at £49,995 which was too high so never sold. They initially offered it at £47k, then £45,750 and then eventually £45k. I still think there was more in the deal but it felt fair to me and hopefully to them.
What I found odd is that they wouldn’t take a debit card for more than £2k over the phone!? Money laundering rules apparently. They wanted the rest as a BACS transfer. In all my years I’ve never heard this. Is this just a Covid thing or a BMW thing now.
Anyway. In the end we decided I’ll pay the balance through their chip and pin when I collect.
Very excited
I offered and paid £45k for 2015 Protonic Blue car with 3500 miles. It was up a few months ago at £49,995 which was too high so never sold. They initially offered it at £47k, then £45,750 and then eventually £45k. I still think there was more in the deal but it felt fair to me and hopefully to them.
What I found odd is that they wouldn’t take a debit card for more than £2k over the phone!? Money laundering rules apparently. They wanted the rest as a BACS transfer. In all my years I’ve never heard this. Is this just a Covid thing or a BMW thing now.
Anyway. In the end we decided I’ll pay the balance through their chip and pin when I collect.
Very excited
PGNSagaris said:
I’d imagine £8k in year one is totally expected (dealer margin mostly) and then it would plateau a bit over the years.
I offered and paid £45k for 2015 Protonic Blue car with 3500 miles. It was up a few months ago at £49,995 which was too high so never sold. They initially offered it at £47k, then £45,750 and then eventually £45k. I still think there was more in the deal but it felt fair to me and hopefully to them.
What I found odd is that they wouldn’t take a debit card for more than £2k over the phone!? Money laundering rules apparently. They wanted the rest as a BACS transfer. In all my years I’ve never heard this. Is this just a Covid thing or a BMW thing now.
Anyway. In the end we decided I’ll pay the balance through their chip and pin when I collect.
Very excited
Not as loud as a Sagaris you know. I offered and paid £45k for 2015 Protonic Blue car with 3500 miles. It was up a few months ago at £49,995 which was too high so never sold. They initially offered it at £47k, then £45,750 and then eventually £45k. I still think there was more in the deal but it felt fair to me and hopefully to them.
What I found odd is that they wouldn’t take a debit card for more than £2k over the phone!? Money laundering rules apparently. They wanted the rest as a BACS transfer. In all my years I’ve never heard this. Is this just a Covid thing or a BMW thing now.
Anyway. In the end we decided I’ll pay the balance through their chip and pin when I collect.
Very excited

PGNSagaris said:
I’d imagine £8k in year one is totally expected (dealer margin mostly) and then it would plateau a bit over the years.
I offered and paid £45k for 2015 Protonic Blue car with 3500 miles. It was up a few months ago at £49,995 which was too high so never sold. They initially offered it at £47k, then £45,750 and then eventually £45k. I still think there was more in the deal but it felt fair to me and hopefully to them.
What I found odd is that they wouldn’t take a debit card for more than £2k over the phone!? Money laundering rules apparently. They wanted the rest as a BACS transfer. In all my years I’ve never heard this. Is this just a Covid thing or a BMW thing now.
Anyway. In the end we decided I’ll pay the balance through their chip and pin when I collect.
Very excited
The debit card is not surprising. We sold a new Quad bike and took card details over the phone.I offered and paid £45k for 2015 Protonic Blue car with 3500 miles. It was up a few months ago at £49,995 which was too high so never sold. They initially offered it at £47k, then £45,750 and then eventually £45k. I still think there was more in the deal but it felt fair to me and hopefully to them.
What I found odd is that they wouldn’t take a debit card for more than £2k over the phone!? Money laundering rules apparently. They wanted the rest as a BACS transfer. In all my years I’ve never heard this. Is this just a Covid thing or a BMW thing now.
Anyway. In the end we decided I’ll pay the balance through their chip and pin when I collect.
Very excited
6 weeks later we had a clawback from the card company as the card had allegedly been fraudulently used.
We got lucky and the bike was found near Leeds so didn't lose out.
At least with BACS it is secure.
We would still take card in person, but not over the phone.
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