openinverter forum

Hello there!

I have seen online that the stock leaf inverter won't correctly start unless you have ~155V+ available:

I am looking at options for a classic Mini EV conversion, and getting voltage that high (>155V) requires quite a lot of cells - this is hard to package in a small car!

The open-inverter doesn't have this limit, and will run on much less - I see that another user here has talked about running their open-modded leaf inverter with as low as 12V input (viewtopic.php?f=4&t=236). Though the control circuitry will run with a lower amount, I want to understand the impact of lower voltage on performance of the leaf inverter and motor package.

Can the inverter still power the motor up to the full 80+kw given a lower voltage (eg 100v) with a higher current draw, or does less voltage mean less power in this case? Any guidance on the tradeoff of voltage vs performance would be appreciated.

You can reach the stock 80 kW down to about 300V. After that I'd expected a linear decrease. So 100V -> about 25 kW

thetoolman wrote: ↑Sat Sep 04, 2021 12:15 pm Can the inverter still power the motor up to the full 80+kw given a lower voltage (eg 100v) with a higher current draw, or does less voltage mean less power in this case? Any guidance on the tradeoff of voltage vs performance would be appreciated.

Leaf motor has wire bundle windings. It shouldnt be difficult to find some specialist for rewinding. They would copy motor winding schematic and recalculate turns and wire thickness. That would mean your motor will accept full power at lower voltage.

There are many >300V PHEV battery packs that probably can fit in a classic mini: for example the 16S 25Ah BMW modules, 6 or 5 of which would happily feed a Leaf OEM system. Of course if you need the highest energy to weight ratio, those might not be an option.

Thanks for your knowledge!

I don't know if the power output is reduced directly in line with voltage reduction or not but even if it is then if you can fit a 200V to 250V pack in the car it will still have reasonable power for a classic mini. The Leaf is 80kW at 96S or just under 400V. Half of that is still 40kw or around 55hp. It's not a lot in todays terms but about the same as a 1275GT.

I am looking to build something pretty quick, and 40kw won't cut it. I'm reasonably competent with electronics, but new to the EV space so still reading up on battery configurations, their options and trade offs.

I'm wondering how compact a 96S1P module can be built. At the risk of wandering too far from the forum topic of inverters, any suggestions here welcomed. One interesting option is this LG Chem 7S1P module, but I can't find anyone else talking about them.. perhaps because they are reasonably new?

thetoolman wrote: ↑Mon Sep 06, 2021 11:03 am I am looking to build something pretty quick, and 40kw won't cut it. I'm reasonably competent with electronics, but new to the EV space so still reading up on battery configurations, their options and trade offs.

I'm wondering how compact a 96S1P module can be built. At the risk of wandering too far from the forum topic of inverters, any suggestions here welcomed. One interesting option is this LG Chem 7S1P module, but I can't find anyone else talking about them.. perhaps because they are reasonably new?

16.75" x 5" x 4" by 13 modules

Would you have space for them in a Mini? Maybe Celeron55 suggestion would be better.