Mixing motors and batteries

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Scubascooby
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Mixing motors and batteries

Post by Scubascooby »

I see many builds mix components from different manufacturers, Tesla batteries, Lexus motors, etc.

I'm not an electronics engineer (physics and computer science degree a long time ago). How do you know which components will work together ?

For example the Leaf 62kWh pack is ~352V.

Should it always be used with the Leaf inverter or should the inverter match the chosen motor ?

I think I don't understand enough about the OI.
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m.art.y
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Re: Mixing motors and batteries

Post by m.art.y »

Hi, most AC OEM motors/inverters nowadays are designed to work from ~250 to ~400 VDC more or less. Motor and inverter usually has to be matched but some inverters are configurable and can run pretty much any motor (Prius inverters with an OI control board replacement). You can use any battery though as long as it has the right voltage.
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Re: Mixing motors and batteries

Post by Scubascooby »

Thanks.

So if I was using a Lexus motor, it should be paired with its matching inverter but it could use Leaf batteries.

Does that also mean that it's not necessary to use all of the donor battery pack ? So if only 15 of the 16 modules fit it could still work ?
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P.S.Mangelsdorf
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Re: Mixing motors and batteries

Post by P.S.Mangelsdorf »

Scubascooby wrote: Wed May 24, 2023 8:07 am Does that also mean that it's not necessary to use all of the donor battery pack ? So if only 15 of the 16 modules fit it could still work ?
Generally speaking, yes you can remove a module and be ok. What you'll want to figure out is what max and min voltage that will leave you with.
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Jacobsmess
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Re: Mixing motors and batteries

Post by Jacobsmess »

P.S.Mangelsdorf wrote: Wed May 24, 2023 11:55 pm Generally speaking, yes you can remove a module and be ok. What you'll want to figure out is what max and min voltage that will leave you with.
Also you need to ensure your BMS will work with the reduced pack size
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Re: Mixing motors and batteries

Post by Jacobsmess »

P.S.Mangelsdorf wrote: Wed May 24, 2023 11:55 pm Generally speaking, yes you can remove a module and be ok. What you'll want to figure out is what max and min voltage that will leave you with.
Also you need to ensure your BMS will work with the reduced pack size
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janosch
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Re: Mixing motors and batteries

Post by janosch »

Great questions.
Scubascooby wrote: Wed May 24, 2023 8:07 am So if I was using a Lexus motor, it should be paired with its matching inverter but it could use Leaf batteries.
Thats right in principle.

Most OEMs at the moment have battery packs that are 96S. So if you are not comfortable with the electronics yet you should keep it that way and then many components will work.

I would try quite hard to keep it 96S, given that onboard charger, DCDC converter, inverter, fuses, connectors, BMS are all set up for a system like that at the moment unless you take a Taycan apart or similar.

Mixing inverter and motor is a no/no for the first build I think. The less comfortable you are, the more boring and middle of the road I would set my aim for the EV you are building, there is still so much to learn regardless.
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