New EV buyer question about replacement batteries

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ksptn

Member
Joined
Jul 6, 2020
Messages
5
Hi. I am considering buying a 2017 i3 (two choices - one with 11K on it and one with 14K on it). I think they are both 60Ah, because neither has the Range Extender.

I drive conservatively, and my round-trip commute is ~ 30 miles of secondary roads. The farthest I drive normally would be ~25 miles to the airport, and I'd like this car to be my daily driver for the next four to six years.

I'm nervous about buying a fully EV because I don't know a lot about them, particularly how long I can expect the battery to last. They seem to be very expensive to replace (close to what I would be paying for the car, ~$18K). I expect to be able to charge on public chargers at least two days a week, and the rest of the charging would be off of the wall at home. At the end of 2021, our office is moving to a new space, and that may have chargers as well - still trying to get that question answered.

Am I a good candidate for an EV, or should I just get a gas/electric hybrid until my commute is shorter or my budget increases?
 
The BMW battery warranty is 8-years or 100K miles, the batteries will be replaced if they can't produce at least 70% of their original capacity. Given your stated use pattern, you shouldn't have any issues. Note, lots of DC fast charging degrades the batteries more than using ACV inputs. A source I trust indicates that one charge from 0-100% is the same wear on the battery as ten charges of 90-100%. I plug mine in whenever I get home and leave it there so I always leave with a full charge.

Your maximum range on a charge will depend on the weather, the terrain, and how you drive it, being worse when it's cold out, when climbing a long grade, or extended high speed runs.
 
ksptn said:
Hi. I am considering buying a 2017 i3 (two choices - one with 11K on it and one with 14K on it). I think they are both 60Ah, because neither has the Range Extender.
Very few 2017 i3's had 60 Ah battery packs. Almost all had 94 Ah battery packs including both Base and REx versions. You could verify the battery pack capacities by entering the VIN's in a BMW VIN decoder Website.
 
Thank you both. It is a 94 Ah, I was able to confirm that and I placed the order for it today. Now I wait a week for CarMax to bring it here from Georgia!
 
Congrats! I would say you're an ideal EV candidate.

I'm frankly surprised now often the "cost to replace the battery" question comes up. Nobody ever asks "cost to replace the engine" of a gasoline powered car.

If out of warranty, you have three options:
- pay retail for new
- buy salvage
- part out the car

They'll probably be a "rebuild" option one of these days. It's complicated because there's an integrated cooling system. But even with a zero battery, there is always value in the remainder of the car.
 
eNate said:
They'll probably be a "rebuild" option one of these days. It's complicated because there's an integrated cooling system.
I believe that the cooling system is basically an aluminum plate through or under which refrigerant flows and upon which 8 12-cell modules sit. A pack rebuilder could just replace the cells in each module and reinstall the modules on the cooling plate, so the cooling system shouldn't add any complexity. I don't know how easy it will be for a pack rebuilder to buy new 60 Ah Samsung SDI cells after the earliest pack warranties begin expiring in significant numbers in 2022. I suppose 94 Ah cells could be used without too much trouble. However, by 2022, new 94 Ah might not be available, either.

I suppose Samsung SDI must continue supplying these old cells to BMW for their warranty replacement packs unless BMW does what Honda did with Insight warranty replacement packs: used cells from packs that Honda had replaced under warranty to build warranty replacement packs. Most of these used cells had some remaining life but not typically the life of a new cell.
 
With a warranty replacement, all they are required to provide is a battery that gets you beyond the initial warranty period. That gives them the option of using either new cells, or used ones strong enough to get you past the warranty. Now, it may be just easier to give you new ones, depending on the supply.

At least in some parts of the world, BMW has been using the entire old battery pack to build storage for solar cell or network storage that has the required inverter and other bits to make it all work. It would be interesting if they provided that to homeowners where their vehicle had reached the end of life. I don't know if this is available retail anywhere, but I've read a press release on their engineering that enabled the use of the battery packs in this manner.
 
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