Battery Upgrade

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tobiassej

Active member
Joined
Aug 9, 2015
Messages
40
Location
Denmark
Have anyone experience with upgrading existing batteries and the internal AC charger?

I have a 60 ah but would like to be able to charge 11 kWh also and upgrade the battery instead of buying a new car.

https://pushevs.com/2018/01/22/best-ev-prismatic-battery-cells-chinese/

The upcoming 160 ah looks interesting.

This article mentions new batteries that should be able to retrofit into the I3. I'm sure BMW would like us all to by new cars instead of exchanging batteries in cars that apart from short range works perfectly well...

I have driven 75000 km and have lost approx. 4-5% pr 10.000 km. After BMW service I'm back to the original kWh (18.8 kWh) on the battery seems they give me more acces to the 22 kWh battery.
 
I just had my Electrical Engine Generator replaced and in RealOEM they list two types 22Kw and 33KW generators, so its not just the battery that is different on the two models, probably charger as well!
 
Interesting. It could be just the logic is different, as detecting the state of charge and how much and long it will take to recharge the battery pack may be embedded, verses programmable in the field. Some markets do have a higher capacity on-board charging (3-phase), but that is not sold in the USA at this time. It may never be sold in the USA. Upgrading to the super high 350Kwhr DC fast charger won't happen without major changes, either as those appear to need an 800v pack verses the 380 or so we have in the i3.
 
Different LIM, Charger KLE, cables and for REX different EME.

But the 94Ah pack will fit. Needs new bolts and aircon gas refill (EU has 1234yf not R134a).
 
I couldn't really get a straight answer from anyone, but the prices in USD vary quite a bit from what people are "reporting". Anywhere from $10k to over $13k. No one in the US has ever done it as far as I know. The one that was done overseas somewhere was not done as a simple upgrade. I forget the circumstance, but basically no one is really doing this and BMW doesn't offer it in the US as of now.
 
If BMW doesn't offer an upgrade service, The main roadblock would be figuring out how to make the car recognize it has the higher capacity batteries...

However some additional things to consider:

If the overall weight of the i3 increased by 160-something pounds when going from a 60AH to a 94AH - so roughly 160lbs for every 34ah. That would mean with the 160ah/56.8Kwh battery would be approx. 480 lbs in additional weight from the original 60AH battery. That is assuming the cooling system or any other auxiliary systems do not need to be upgraded....Also 0-60 mph dropped from 6.5 seconds to 7 seconds from 60AH to 94AH....assuming the drop is linear (probably not?), the 0-60 time would now be 8 seconds with the 160AH.

Shocks/springs/suspension would need to be upgraded. Would the Aluminum drive module would be able to handle the additional weight? Impact on tire life and road handling? If needing larger tires, I wonder if the wider i3s wheels/tires would suffice...that would also mean needing fender flares installed....if going this far, I wonder if the only difference between the i3s and i3 electric motor is a bit of coding?

Watching the video of the Battery pack assembly (7:50 to 15:50): https://youtu.be/gt1k3BLN7pw?t=468 - If upgrading the battery was an aftermarket item - it looks like they would have to provide entire modules (8 of them) - the individual prismatic batteries (12 per module) are glued in, in addition to the welding of the contacts...If BMW were to offer this service, they may decide just swapping the entire battery pack and reusing the old pack in their power storage solutions to be a better solution.
 
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