AgentiMi
Posts: 8
Joined: Tue Feb 16, 2021 1:39 pm

i3 HV Battery Upgrade

Tue Feb 16, 2021 1:53 pm

(This is a repost from the i3 Reddit page.)

I work for a stationary energy storage company and I need an excuse to develop i3 batteries.

I wanna know just how many of you would actually buy an upgraded battery.... they are pricy... almost as much as 2 used i3s.

Here's what you will get IF we make this product:

-10-year capacity warranty.

-Increased range.

-Increased power output of the pack for modified applications.

-Faster DC charging, from 40kW to 250kW peak.

-Battery condition on climatize.

-We'll offer installation and financing.

The modules are already developed for our large stationary storage systems (300kWh+) an example application is DCFC stations. We are playing with the idea to put these packs in classic cars and it hit me. Why not the i3? or any EV.

I've made a list of possible configurations below, please vote if you would actually buy one if it was offered.

Side note. You will also need different springs and dampers in some applications, good luck.

-------------------

Cost values are for the battery pack only.

Range values are estimates in COMFORT mode driving.

kWh values indicate total usable energy and do NOT include battery buffer.

We are not asking for money. This is just to show you how much a battery pack will cost.

**** may require a different battery tray, adding to the cost.

-------------------


Here are the possible configurations listed below.

~80 miles (129km) 19kWh $6K (50kW DCFC)

~120 miles (193km) 30kWh $9.8K (70kW DCFC)

~160 miles (257km) 40kWh $13K (100kW DCFC)

~260 miles (257km) 69kWh $21.3K (150kW DCFC)

****~320 miles (515km) 90kWh $24.5K (250kW DCFC)

--------------------

I'm happy to answer questions!

We're also hiring for more engineering positions soon. Maryland and remote. I'll post about it.

djbrh
Posts: 10
Joined: Mon Dec 07, 2020 5:57 pm

Re: i3 HV Battery Upgrade

Fri Feb 19, 2021 4:39 pm

I would definitely do this. Which one, I’m not sure.

My car is a 2014 with 62k on it that I bought used a few months ago. I got it pretty cheap, but it wasn’t well taken care of and was a low option model. It was dealer serviced and taken care of in that respect, and the kappa is still very good on it. I’ve upgraded things like CarPlay (MMI), 10.25” display, coding, etc.

I love the car. A lot. I would probably pick the 40KWh option, but it’s hard to be sure. I think the higher options are neat, but my guess is few would pull THAT trigger. Hard to say.

A question: does the price include me getting to keep my old battery, or does it include YOU keeping it?

And it’s so intriguing that if you need a beta tester, well, I’d bring my car to MD and drop it off for you. For some kind of reasonable incentive, anyway. :D


—Donnie

i3sDan
Posts: 5
Joined: Tue Feb 02, 2021 5:29 am

Re: i3 HV Battery Upgrade

Wed Mar 03, 2021 4:35 am

With current trends I would go for 69kWh or 90kWh
My question would be only the price for my old battery. Now I a 94Ah (30kWh) pack and upgrade to 120Ah (40kWh) cost ±€5.0K but they take my old battery for reuse in different needs (home backup energy storage).

Would you also offer an upgrade or your price includes the price for my old battery?

I would also go just for an DCFC upgrade as well, this sounds like an attractive option ;)

eXodus
Posts: 136
Joined: Tue Dec 22, 2020 6:06 am

Re: i3 HV Battery Upgrade

Wed Mar 03, 2021 10:58 am

I'm perfectly happy with my 94ah - 30kwh battery size.

Yet, if I would need to upgrade at some point in the future - I would definitely want to go larger then that - 50-60kwh

The 69kwh sounds kind of pricy. I can get a 2019 120ah (44kwh) full car for that price.

alohart
Posts: 2430
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: i3 HV Battery Upgrade

Wed Mar 03, 2021 11:34 am

Unless energy density increases considerably, the weight of the larger battery packs would be an issue. Stronger springs and appropriate shocks aren't accessories that are available for an i3. Tires with a greater load capacity might also be needed and which might be difficult to find.

The i3's battery pack cooling system is designed to remove only so much heat. A larger capacity battery pack would likely generate more heat. Without the cooling system being upgraded (expensive!), could overheating be a problem in hot climates?

Also, the battery cell chemistry best for storage isn't best for EV use. I'm pretty sure that Tesla uses different battery chemistry for its storage products compared with its vehicles. So I wouldn't necessarily want storage modules used in an i3 battery pack upgrade. Maybe different cells would be used in these battery pack upgrades.

I hope that more 3rd-party battery pack builders start producing replacement packs for the i3 and other EV's as has happened with some gasoline-electric hybrid vehicles. However, the engineering challenges are significant. If these aren't handled well, a 3rd-party pack could be disappointing.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

eXodus
Posts: 136
Joined: Tue Dec 22, 2020 6:06 am

Re: i3 HV Battery Upgrade

Wed Mar 03, 2021 12:27 pm

alohart wrote:
Wed Mar 03, 2021 11:34 am
Unless energy density increases considerably, the weight of the larger battery packs would be an issue. Stronger springs and appropriate shocks aren't accessories that are available for an i3. Tires with a greater load capacity might also be needed and which might be difficult to find.

The i3's battery pack cooling system is designed to remove only so much heat. A larger capacity battery pack would likely generate more heat. Without the cooling system being upgraded (expensive!), could overheating be a problem in hot climates?

I hope that more 3rd-party battery pack builders start producing replacement packs for the i3 and other EV's as has happened with some gasoline-electric hybrid vehicles. However, the engineering challenges are significant. If these aren't handled well, a 3rd-party pack could be disappointing.
Energy density in LIPO4 already increased drastically per kg. Newer battery chemistries are more efficient - thus they do not heat up as much.
The 120AH battery has already a different cooling tray then the 94ah version.

I can get 18650 cells with almost double the energy then I got 5 years ago - at the same weight.
Even if the car would be 100-200lbs heavier - that's nothing the suspension shouldn't be able to handle. It's like driving around with a passenger all day.

You have to think - a car manufacturer designs it that 4 grown adults + luggage could drive in the car every day.
If you are not doing that - a little few more points should be ok with the current suspension.

AgentiMi
Posts: 8
Joined: Tue Feb 16, 2021 1:39 pm

Re: i3 HV Battery Upgrade

Thu Mar 11, 2021 4:38 pm

djbrh wrote:
Fri Feb 19, 2021 4:39 pm
I would definitely do this. Which one, I’m not sure.

My car is a 2014 with 62k on it that I bought used a few months ago. I got it pretty cheap, but it wasn’t well taken care of and was a low option model. It was dealer serviced and taken care of in that respect, and the kappa is still very good on it. I’ve upgraded things like CarPlay (MMI), 10.25” display, coding, etc.

I love the car. A lot. I would probably pick the 40KWh option, but it’s hard to be sure. I think the higher options are neat, but my guess is few would pull THAT trigger. Hard to say.

A question: does the price include me getting to keep my old battery, or does it include YOU keeping it?

And it’s so intriguing that if you need a beta tester, well, I’d bring my car to MD and drop it off for you. For some kind of reasonable incentive, anyway. :D


—Donnie
The prices I've quoted include manufacturing and material costs. If you decide to sell your pack then we'll deduct that cost from the new packs. Also, the range numbers are also estimates. We still have to pick a range and focus on just one pack to build for the i3.

That would be awesome. I'm first in line to test the packs ;D, then we'll release betas, given that we make good progress. For now, we're just building out the factory.

AgentiMi
Posts: 8
Joined: Tue Feb 16, 2021 1:39 pm

Re: i3 HV Battery Upgrade

Thu Mar 11, 2021 4:48 pm

alohart wrote:
Wed Mar 03, 2021 11:34 am
Unless energy density increases considerably, the weight of the larger battery packs would be an issue. Stronger springs and appropriate shocks aren't accessories that are available for an i3. Tires with a greater load capacity might also be needed and which might be difficult to find.

The i3's battery pack cooling system is designed to remove only so much heat. A larger capacity battery pack would likely generate more heat. Without the cooling system being upgraded (expensive!), could overheating be a problem in hot climates?

Also, the battery cell chemistry best for storage isn't best for EV use. I'm pretty sure that Tesla uses different battery chemistry for its storage products compared with its vehicles. So I wouldn't necessarily want storage modules used in an i3 battery pack upgrade. Maybe different cells would be used in these battery pack upgrades.

I hope that more 3rd-party battery pack builders start producing replacement packs for the i3 and other EV's as has happened with some gasoline-electric hybrid vehicles. However, the engineering challenges are significant. If these aren't handled well, a 3rd-party pack could be disappointing.
Cell density has already increased significantly since the i3 came to market. We also extract way more energy out of the battery (less internal resistance), less energy will be lost to heat with.... special.... cells. that's as much as I'm willing to say ;D. So don't worry about weight differences.

We're fully aware of the chemistry and cooling differences. We're going to be using appropriate cell chemistry paired with a new thermal management system to provide the best experience. Don't worry at all about the characteristics of these packs, I personally won't allow it to be made if it's at least not better than the original BMW packs. I'm fully committed to keeping development costs out of the equation to keep the cost down for the customer.

AgentiMi
Posts: 8
Joined: Tue Feb 16, 2021 1:39 pm

Re: i3 HV Battery Upgrade

Thu Mar 11, 2021 4:51 pm

eXodus wrote:
Wed Mar 03, 2021 10:58 am
I'm perfectly happy with my 94ah - 30kwh battery size.

Yet, if I would need to upgrade at some point in the future - I would definitely want to go larger then that - 50-60kwh

The 69kwh sounds kind of pricy. I can get a 2019 120ah (44kwh) full car for that price.
There will be enough incentives for you to upgrade to make it well worth it over trading in your car.

AgentiMi
Posts: 8
Joined: Tue Feb 16, 2021 1:39 pm

Re: i3 HV Battery Upgrade

Thu Mar 11, 2021 4:55 pm

eXodus wrote:
Wed Mar 03, 2021 12:27 pm
alohart wrote:
Wed Mar 03, 2021 11:34 am
Unless energy density increases considerably, the weight of the larger battery packs would be an issue. Stronger springs and appropriate shocks aren't accessories that are available for an i3. Tires with a greater load capacity might also be needed and which might be difficult to find.

The i3's battery pack cooling system is designed to remove only so much heat. A larger capacity battery pack would likely generate more heat. Without the cooling system being upgraded (expensive!), could overheating be a problem in hot climates?

I hope that more 3rd-party battery pack builders start producing replacement packs for the i3 and other EV's as has happened with some gasoline-electric hybrid vehicles. However, the engineering challenges are significant. If these aren't handled well, a 3rd-party pack could be disappointing.
Energy density in LIPO4 already increased drastically per kg. Newer battery chemistries are more efficient - thus they do not heat up as much.
The 120AH battery has already a different cooling tray then the 94ah version.

I can get 18650 cells with almost double the energy then I got 5 years ago - at the same weight.
Even if the car would be 100-200lbs heavier - that's nothing the suspension shouldn't be able to handle. It's like driving around with a passenger all day.

You have to think - a car manufacturer designs it that 4 grown adults + luggage could drive in the car every day.
If you are not doing that - a little few more points should be ok with the current suspension.
The new packs will have a nearly identical mass compared to the older packs. Chemistry is much better. Lower internal resistance. Active balance BMS. No 18650s, these cells are much bigger, still cylinders though, wink... wink.

Return to “News and Main BMW i3 Forum Discussions”