60Ah vs 94Ah battery longevity

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Srivenkat

Well-known member
Joined
Apr 21, 2018
Messages
88
I am wondering how the 2017 94Ah battery is doing in terms of degradation, now that it has been out a couple of years; search hasn't turned up anything. Any real world experiences out there?

Thanks in advance.
 
A 94 Ah battery pack would experience ~57% fewer charge/discharge cycles per unit distance driven compare with a 60 Ah battery pack. One of the factors affecting the battery cell degradation rate is the number of charge/discharge cycles. Another factor is the time spent at very high or very low charge levels which could be less for a 94 Ah battery pack assuming that the owner manages charge level to accomplish her range goals. So the degradation rate of a 94 Ah battery pack should be less than that of a 60 Ah battery pack.

Other factors affecting the degradation rate are the age of the battery pack and the time spent at very high or very low temperatures. However, these factors would be no different for a 94 Ah or 60 Ah battery pack.

The cell chemistry of a 94 Ah cell must be slightly different from that of a 60 Ah cell as reflected by their slightly different voltages and different energy densities. I don't know how this affects the degradation rate.
 
Samsung SDI expects up to 4,600 charging cycles at 25ºC to End-Of-Life (EOL), for the 94 Ah i3 battery pack, which in the case of batteries is the point when capacity decreases to 80% (battery still can be used, but is generally not desirable in cars any longer).

Since the BMW i3 (33 kWh) is rated at 114 miles (183 km), 4,600 cycles would be more than 524,000 miles (more than 843,000 km).

And yes, these are stats directly from Samsung - but publishing battery specs that end up not verifiable real-world would open Samsung up to major costly lawsuits from its customer base, not to mention loss of reputation and future sales.

https://insideevs.com/news/338067/bmw-i3-samsung-sdi-94-ah-battery-rated-for-524000-miles/
 
I'm not sure if this info will help but my car is the BEV 94ah bought in march 2017. We've put 50,000 km onto the car. I checked the secret menu max kpa I think it's called, showed 29.5.... We charge mostly every night and put about 80 km per day onto the vehicle.
 
coho said:
I'm not sure if this info will help but my car is the BEV 94ah bought in march 2017. We've put 50,000 km onto the car. I checked the secret menu max kpa I think it's called, showed 29.5.... We charge mostly every night and put about 80 km per day onto the vehicle.

Its because what you see is usable capacity, not battery capacity. I know that for the 22 KWH battery, what it would read for most new owners was 18.8 KWH. Mine is at 18.5 KWH with almost 20K mi on it.
 
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