i3 Battery pack battery hookup

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scozza12345
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i3 Battery pack battery hookup

Post by scozza12345 »

Hi all,

I am looking at taking on a project to add an external battery pack to my i3, connected directly to the main i3 battery. This external battery has some degree of voltage balancing, and its own BMS.

Asides from the software modifications that will be needed for the i3's BMS, can someone help me to outline what other requirements and modifications will be needed to the i3's battery pack, to allow it to connect with the external pack? Has anyone attempted anything similar on an i3 battery for any application, and able to share some information about the process? I'm able to access and open up the i3 pack, and remove battery modules if needed.

A big thank you for any help.

Rory
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Re: i3 Battery pack battery hookup

Post by EV_Builder »

The challenge is that you need to combine information from 2 BMS's into one for the dashboard.

The second priority is that the OEM BMS doesn't drop out with errors.

In practice you need to solve Charging current setpoints and soc estimates etc. etc.
Converting an Porsche Panamera
see http://www.wdrautomatisering.nl for bespoke BMS modules.
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Re: i3 Battery pack battery hookup

Post by arber333 »

scozza12345 wrote: Tue May 30, 2023 2:37 pm Hi all,

I am looking at taking on a project to add an external battery pack to my i3, connected directly to the main i3 battery. This external battery has some degree of voltage balancing, and its own BMS.

Asides from the software modifications that will be needed for the i3's BMS, can someone help me to outline what other requirements and modifications will be needed to the i3's battery pack, to allow it to connect with the external pack? Has anyone attempted anything similar on an i3 battery for any application, and able to share some information about the process? I'm able to access and open up the i3 pack, and remove battery modules if needed.

A big thank you for any help.

Rory
I made a range extender pack from VW GTE pack for our Ampera car. Its ob this forum...

First you need to connect both packs in parallel after the main contactor. If contactor is inside main pack that could be a lot of work.

2nd pack needs to be 96S and i recommend at least another contactor on HV+ side.

Maybe you can put a power diode in reverse across that contactor so you are able to charge both packs via OEM charger...

I think 2nd BMS needs to be able to open contactor in semiauto way... When undervoltage would happen on the second pack contactor would be disengaged. To reengage you would need to restart the car.

What kind of battery for this range extender?
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