# i3 Battery in Conversion



## catalyst00 (Feb 14, 2018)

Hi

I'm new to the forums and wanted to know if anyone has had experience using a BMW i3 battery in their conversion? I searched through the forum posts but I wasn't able to find any. I've also searched the internet and didn't find any one who used an i3 pack in the DIY ev. I'm guessing the lack of information is due to the high cost of the battery pack as well as the low sales volume of the i3's.

Thoughts?


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## nucleus (May 18, 2012)

Wrecked ones show up on a regular basis around here, I think you could get one for 5-6K USD.


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## catalyst00 (Feb 14, 2018)

nucleus said:


> Wrecked ones show up on a regular basis around here, I think you could get one for 5-6K USD.


I was more interested in learning or following someones build to see what they experienced while they used them in their EV. Or how they setup the cells and modules, what kind of charger they used, what kind of converter, etc. There are a LOT of builds with salvaged Chevy Volt cells.


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## nucleus (May 18, 2012)

catalyst00 said:


> I was more interested in learning or following someones build to see what they experienced while they used them in their EV. Or how they setup the cells and modules, what kind of charger they used, what kind of converter, etc. There are a LOT of builds with salvaged Chevy Volt cells.


Yeah, I know. I was just offering what I know. I assume you know that Damien Maguire is developing a controller chip for the i3.


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## catalyst00 (Feb 14, 2018)

nucleus said:


> Yeah, I know. I was just offering what I know. I assume you know that Damien Maguire is developing a controller chip for the i3.


Oh ok  thanks. No, I didn't know that. I just Googled him and found some of his videos, I appreciate it. I'll watch some of them and see what I can pick up. 

BTW - I'm guessing the controller chip is the hardware on the controller? Would that enable someone to use the i3's controller in their EV? I'm pretty new to this stuff.


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## brian_ (Feb 7, 2017)

I have no experience with the i3 battery, and don't know much about it. Do you at least have descriptive information about the battery, even if no reports of DIY projects?

It appears that this battery contains eight identical 12s (45 V nominal) modules, for a total of 360 V (nominal). They are all mounted under the (very high) carbon-fibre composite floor, between the rails of an aluminum frame. There appear to be two capacities:

60 Ah modules for 22 kWh (nominal) / 18.8 kWh (usable)
94 Ah modules for 33 kWh (nominal)
I don't even know what it has for thermal management. The BMS is reportedly modular, with controllers mounted in each module. It sounds like keeping modules intact, but re-arranging modules to suit the vehicle, is the way to go with this one... but that's just a guess.


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## Kevin Sharpe (Jul 4, 2011)

catalyst00 said:


> Oh ok  thanks. No, I didn't know that. I just Googled him and found some of his videos, I appreciate it. I'll watch some of them and see what I can pick up.


DIY BMW i3 Controller (see here)


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## GreenTecAuto (Jun 14, 2017)

catalyst00 said:


> I was more interested in learning or following someones build to see what they experienced while they used them in their EV. Or how they setup the cells and modules, what kind of charger they used, what kind of converter, etc. There are a LOT of builds with salvaged Chevy Volt cells.



I sold 3 of the modules to someone for a golf cart conversion. 
He works as a shuttle bringing people from events to their cars.
He said he got 30 mile range on a full charge carrying up to 6 people back and forth.
To answer some of your battery questions, the cells are Samsung SDI 64Ah cells. They are assembled into 12s modules by Bosch. Total of 8 modules. The bus bars are laser welded on, so it would be tough to rearrange any of the cells. They each have their own BMS that gets daisy chained.
They have both heating and cooling integrated beneath the pack.
AC lines run the length of the pack, coming into contact with the base of each cell. When the pack is hot, a valve opens up letting the Freon flow through the pack to cool it.
Between the AC lines and cells, is a resistive heater. It uses the high voltage of the battery to warm up the cells. 
Ive attached a picture of what the AC lines look like. They are from a smaller battery that only has cooling, no heater. But its the same idea.
Here are some pictures and info about the module.
https://www.ebay.com/itm/48V-63Ah-B...ash=item33dad1f7e7:g:TqcAAOSwnCFaBiOD&vxp=mtr


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## catalyst00 (Feb 14, 2018)

Thanks for the info GreenTechAuto! I was hoping for an answer like this.


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