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Tuning the Lithium cars for more IMA power.

10255 Views 101 Replies 10 Participants Last post by  PeterPerkins
Tuning the Lithium cars for more IMA power.

You will have seen my long thread on tuning the Nimh system for more IMA power.


In that I hacked the current and the voltage to double the motor Kw output. It was very lively. :p

It involved swapping in a Lithium car inverter and dc-dc converter and using the cars original Nimh BCM/MCM module along with an up-rated 200A fuse.

So what can we do with the Lithium cars?

Well we can hack the current in exactly the same was as we did for the Nimh setup.
This will likely get us another 5-7kw or so. Taking us to ~20kw+...

The voltage is more tricky in the Lithium cars especially if we want to keep the Lithium control modules.

The Lithium MCM/BCM gets it's voltage data from three places.

1) The four BMS CAN boards on the pack.
2) A HV input into the BCM. (We can fake this as per Nimh with a very low current HV supply)
3) Serial data from the IPU IGBT module. (We can fake this as per Nimh)

So to tackle 1)

Can we make an interceptor type device that will send out perfect 75% SOC equivalent cell voltages on the CAN bus?
I'm saying 75% as at that voltage equivalent about 3.8V per cell the car will allow full assist and regen.

Yes I think we probably can fool the voltages, but this only gets us to around 190V which is where the OEM Lithium DC-DC and IGBT module max out.

To go higher we might need to use the HCH2 DC-DC which goes to 220V and possibly the HCH2 IGBT module which probably goes to a similar voltage.

That should get us firmly in the 30kw+ camp with a suitable battery pack.

Now to go even higher we need more voltage.. :eek:

So what IMA cars have higher voltage packs?
Do these dc-dc converters and inverters use the same data stream for control as the CR-Z etc? I bet they are similar.

So would a CRV 2019 or Jazz dc-dc and inverter work in a CR-Z????? Only one way to find out..

But before I start buying expensive parts.........

I'm going to need access to the Honda workshop manuals for these later models to check specs and wiring for compatibility.
Does anyone have current Honda subscription access to this data? Can you message me please.
If people want to support this research in some other way then feel free to message me.

Have a good Christmas and Thanksgiving etc. Peter UK
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There are a few potential deal breaking issues putting an HCH2 IMA into a CR-Z.

The CAN messages may be incompatible and un-correctable.

The CR-Z Rotor position sensor may not be exactly the same as the HCH2. (They look the same electrically etc)
Both IMA motors have 18 stator coils so should be compatible. .

The HDS will not let us do the rotor position calibration if there are any IMA dtc's
Might get lucky with the alignment.... 🤞

Probably other stuff I haven't thought about yet..

Almost certainly need a CAN message faker of some sort as the HCH2 has an electric air-con compressor driven by a special IMA powered inverter.
If we take that out something is bound to complain about it being awol!
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6
OK Let's look at the 5v bidirectional battery current sensor. (2.5V = 0A)

Passive circuit component Circuit component Hardware programmer Electronic component Electronic device


Circuit component Passive circuit component Hardware programmer Computer hardware Electric blue


The 20 pin chip is ISC101E (061012) (Google doesn't come up with anything very useful)

If we fool the 3 phase sensors we have to fool the battery current sensor by the same % amount. (let's use 20% for example)

The battery currents sensor has two outputs ISOC- and ISOC+
These are driven directly from the sensor opamp chip outputs. (no series resistors in the sensor)

Inside the BCM is a 4.7k resistor between ISOC- and ISOC+ (Blue marks on pic)

ISOC- line has an 11.8k resistance to ground inside the BCM.
ISOC+line has an 7k resistance to ground inside the BCM.

Circuit component Hardware programmer Passive circuit component Electronic component Electronic engineering


There is then a collection of high precsion resistors in some sort of matrix. :unsure:

Circuit component Hardware programmer Electronic engineering Electronic component Engineering


Rectangle Schematic Font Parallel Pattern


I measured the voltage swings on both sensors outputs in both directions with known currents 10,20,30A

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Looks like some sort of differential sensor.

Anyway we need to reduce the current it sees (output voltage swing) by 20% to match the phase sensors for the initial current hack testing. :eek:
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I'm looking for the type of IC, i see UART (or SPI) pins on it with test points. Can you hook up an adapter and read from them while it's operating?

Ok it looks like a programmable differential dual amplifier. Should be able to reprogram the gain via SPI.

Also if it's a differential signal, can we just change R122 (BCM) to a lower value? If we put in something that's just a tiny bit lower we can remeasure and see the effect.
I will try replacing the 4.7k with a 3.9k and see what happens.
There are a few potential deal breaking issues putting an HCH2 IMA into a CR-Z.

The CAN messages may be incompatible and un-correctable.

Almost certainly need a CAN message faker of some sort as the HCH2 has an electric air-con compressor driven by a special IMA powered inverter.
If we take that out something is bound to complain about it being awol!
Both of the above issues can be handled via modification of the rom.
I don't have a module to test writing yet, but i have the assumed code taken care of already. However it would require us to make some modifications to the code side of things for it to work.
Changing canmessages comes really easy once you have a data dump, provided we have enough free space in the rom to hook what we want send to a new function that would either overwrite the data that it sends regularly with what we want to send, then add our data to the rom in the specific packets or just constructing our own canbus packets however we see fit :)
But before i can get there, im going to need that ROM and Ram dump :)
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But before i can get there, im going to need that ROM and Ram dump :)
As soon as I get the adapter and a working car I will attempt the HCH2 MCM dump if you can send me idiot level instructions and software links.
As soon as I get the adapter and a working car I will attempt the HCH2 MCM dump if you can send me idiot level instructions and software links.
Don't worry it will be fool proof :)
OK I have a cheap scrap HCH2 on my drive now for data gathering.
It's not driveable on the road but the IMA works and it does move under it's own steam (just)
It will be going to the scrapyard in the spring after I have gathered any data we need and taken the IMA out.
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OK I have a cheap scrap HCH2 on my drive now for data gathering.
It's not driveable on the road but the IMA works and it does move under it's own steam (just)
It will be going to the scrapyard in the spring after I have gathered any data we need and taken the IMA out.
Im currently working on the utility to be as foolproof as possible :D
I might not have it finished this evening(its 1am my time) but i will have it to you by tomorrow at the latest.
There is however one thing i need, I need the address of the inverter module.
it would be an extended 29bit address

something like how

The ECU is 18da10f1
I need whatever the MCM broadcasts on.
After i get that i can finish it up :)
You mean when the HDS is talking to the IMA?

The HCH2 has three separate CAN modules in the IMA box.

The BCM (Battery control module)
The MCM (Motor control module/inverter)
The Air Con compressor module.

I assume you want the MCM module ID..
Re the HCH2

The MCM seems to broadcast on 18DAF102 when sending info

The HDS sends commands to the MCM on 18DA02F1

@Sondair might be able to confirm this..
Also if it's a differential signal, can we just change R122 (BCM) to a lower value? If we put in something that's just a tiny bit lower we can remeasure and see the effect.
Testing the battery current sensor on it's own with a 4.7k resistor across the outputs as per the pcb and then changing it to a 4.3k did not result in any voltage changes.
Testing the battery current sensor on it's own with a 4.7k resistor across the outputs as per the pcb and then changing it to a 4.3k did not result in any voltage changes.
In hindsight the leads are connected straight to the output of an amplifier so i should have known it would compensate for the extra current...

I'm thinking reprogramming via SPI, or putting a voltage divider in are the next best options.
If might try resistors in each signal lead then the 4.7k should pull them closer together.
Re the HCH2

The MCM seems to broadcast on 18DAF102 when sending info

The HDS sends commands to the MCM on 18DA02F1

@Sondair might be able to confirm this..
Great, I have the app done, ill send you a email, it will allow you to dump both the ECU and the MCM I would like one of each please :)

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About the IC, i spotted a resistor (R5) and capacitor (C10) on the back connected to two pins through vias.
What is the resistance of R5?
Can you check via meter to see which pins they are connected to?
So far I've got:
Code:
10 - ?        11 - ?
09 - ground   12 - ?
08 - ?        13 - ?
07 - ?        14 - vout -
06 - ?        15 - vout +
05 - ?        16 - clock
04 - in       17 - serial data in
03 - in       18 - load
02 - in       19 - chip enable
01 - Vcc      20 - serial data out
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@da-coder Will look at sensor pcb in AM.

HCH2 Inverter Design paper attached for info.

Attachments

About the IC, i spotted a resistor (R5) and capacitor (C10) on the back connected to two pins through vias.
What is the resistance of R5?
Can you check via meter to see which pins they are connected to?
So far I've got:
Code:
10 - ?        11 - ?
09 - ground   12 - ?
08 - ?        13 - ?
07 - ?        14 - vout -
06 - ?        15 - vout +
05 - ?        16 - clock
04 - in       17 - serial data in
03 - in       18 - load
02 - in       19 - chip enable
01 - Vcc      20 - serial data out
R5 & C10 are in parallel and unmarked.
R5 in circuit measures 24R but that may well not be right.

R5 connects to pins 2,3,4 of the IC assuming pin 1 is nearest the dot.

I can't tell which pins are connected to which side/s of R5 due to the very low resistance of the circuit.

My meter says continuity basically between any of the pins 2,3,4 and either side of R5.
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