openinverter forum

Hello, I am completely new to EV conversions. I found this open source project and think it would be a fantastic choice for me. I appreciate everyone who has worked on this because it's by far the most cost effective solution for me. I have a 90' integra I want to convert to be hybrid. I am planning on mounting a telsa SDU in the rear with 6 chevy volt battery modules. It should be around 270v and 10kwh. I have a few questions on integrating the two systems together. The car will be used for street strip, the ICE engine is a b18 with a turbo that makes around 350-400hp.

1) When using the electric motor in conjunction with the gas engine I need to use the clutch switch to enable the electric motor so I can use launch control on the gas engine which required clutch in and full throttle. Should I wire the clutch switch to to forward position, or the start input?

2) I wanted to mainly use the EV as a launch assist and disable it after a certain gear, my ecu has canbus and I can program an output based on gear but wasn't sure how to have the inverter interpret this and disable power. I know disconnecting the motor at high current can cause inverter failure. Which then leads to my next question

3) Can the motor free wheel without causing a regen effect If I want to run only the gas engine and have the rear wheels still be spinning up to 130+mph, If this is not the case, would leaving the precharge contactor/relay/circuit enabled be safe when going those speed. or should I be inputting a 0% throttle and leaving the inverter enabled to provide zero regen and zero boost.

4) Sorry for so many questions, I am concerned about having regen coming on when braking hard from high speeds, I am hoping to use the brake switch input to disable regen but I'm curious if i can taper out regen at a certain rate and tune it. Also with the brake switch input does this connect to the brake light input or brake signal, and does the switch need to feed 12v to the input or ground?

Any help here would be greatly appreciated, I will also continue digging into as much information on the forum and wiki as possible to educate myself further

Your way In over your head.

Not recommended to reduce the cell count and voltage of the battery, especially for a high power output application.

More current and more strain on less cells.

“start” is used for pre charge.

Regen is adjustable and only occurs when tuned. But free wheeling a Tesla drive unit will produce transient current.

if cost is a concern… much deeper understanding is required. A hybrid system is an additional layer of complexity. Ontop of a new system you don’t understand yet.

Might be bitting off more than you can chew.

People blow up the Tesla inverters already just trying to get a conversation driving

Thanks for the response, If I'm limiting current to say 250-350 amps with the smaller battery pack is this still not recommended? I would think if the motor is drawing within the battery packs capabilities and the bms/inverter both have low voltage derating or disconnect it should be suitable.

After thinking about the control side of things for a while I think an interface is going to be needed between the controls and inverter. Probably an arduino. So far what I can come up with as a good solution

Inputs
3 position range switch: | Fwd | N | Rev |
3 position Regen Switch: | Regen ON | Regen Off | Only Regen |
Clutch switch from top of pedal
Brake pedal switch
Throttle position sensor 0-5v

The Arduino would have all of the sensors wired to it in a piggy back style to the engine ecu or I can setup a can link between them and output signals that way. To avoid bad code causing an unexpected take off I'll wire the Range switch directly to the inverter but have the arduino see the position or receive it from CAN

The rough "handCode" I've come up with so far without any real parts in front of me is;

Receive 0-5v tps signal from engine side.
If Clutch is down or brake switch down -> Output 0% tps to inverter
if Regen switch is off -> When tps < 0 -> Output 0% tps to inverter
If Regen Switch is "Regen Only" -> when tps > 0% -> output 0% tps to inverter

Outside of those conditions output the real tps voltage downscaled to 3.3v-ish max so it can detect an open and not take off

Any clear errors where I'm not understanding it correctly and it won't work?