[retepsnikrep]

For those with squishy packs that can only do limited assist/regen without falling over a simple limiter circuit is possible.
Limit current except when starting (which is very short duration <1s) to 50 or 25% of the requested amount.
Current limit set by two pots on a tiny pcb or via software update and pcb could be installed in footwell or in ipu compartment.

Something very simple using an 8 pin 12F683 pic is possible on the CMDPWR line for the G1 Insight.

4 wires to connect. 5v power from the ECM or MCM and cut the cmdpwr line (insert device) and pic then simply reduces or boosts requested power by x amount.

Could be programmed for other current reductions or increases in fact!!

So could act as an IMA KERS current boost device for those with good batteries who want more assist/regen at lower throttle levels.
So when car is requesting 50% assist or regen you get 100% etc etc
Can be programmed for assist boost or regen boost only as required.
So for those who don't like using assist but like a full battery, you could limit assist to 50%.
This would mean the battery remains at a higher soc overall as regen levels would be normal.

Circuit is about as simple as it can get. Might keep your struggling battery going for quite a while

Any interest?

 

[uhtrinity]

Haha, you are using my term 'squishy'!! Started saying that when my parallel setup started to develop high IR due to too many cycles and charges. The main symptom is a large drop in pack voltage while under load.

Excellent idea. I would bet a lot of failing packs would run fine for quite a while under a preset limit.

Examples of things I saw:

If assist was kept under 30 - 40 amps I could pull a full 8 or 9 AHs from the parallel setup. But if I tried to pull 50 amps or more it would drop to under 4 - 5 AH's. Much higher discharges would result in an IMA light.

 

[Mario]

Sweet, do you have source code?

 

[retepsnikrep]

Sweet, do you have source code?

I will have soon (code is pretty much written but need to bench test a prototype) but I won't release the source at first.
I need to get the cost of the pcb's back.
Probably looking at $55 inc p&p for a pcb/software.
I'll post the hex files like I do for most of my stuff.

The pcb will fit that tiny box I used for the HCH1 IMAC&C.
http://www.hammondmfg.com/pdf/1551GFL.pdf

I've changed the schematic in the first post slightly and will lay it out today.
I have added two 10k pots so you can independently adjust assist/regen boost or reduction.

One pot is assist.
One pot is regen.
The middle (5k) setting is no effect.
Higher than Mid = boost oem assist or regen.
Lower than Mid = reduce oem assist or regen.

Added a jumper which you remove when programming the device once installed in the car.
Added a bi colour led so you have some feedback.
Added a 100uf cap for a bit more power supply stability.

Even those with MIMA or IMAC&C could use the device installed just before the MCM to limit or boost current with a failing/good pack.

 

[Quebecfrog]

interested

 

[eq1]

Is the adjustment 'across the board' - like whatever the car is putting out or taking in at any given time, the adjustment can add or subtract x%, with independent adjustments for regen and assist? I'm interested, though I'd prefer some way to make adjustments NOT across the board... Like maybe limit boost to only those events under 50 amps, etc... Even better would be programmable TPS settings, like increase assist if TPS <30...

 

[retepsnikrep]

Is the adjustment 'across the board' - like whatever the car is putting out or taking in at any given time, the adjustment can add or subtract x%, with independent adjustments for regen and assist?

Correct.

Your other stuff has been covered by MIMA, if you need that functionality with Tps, Map etc that's what you need.

 

[eq1]

What about thresholds based on the amount of current, such as 'increase assist 75% when amps < 50A'?

 

[klinkenputzer]

Interested.

 

[TopFuelTim]

Interested also

Interested too. My silver and my citrus both threw an IMA last week, and my red one did a negative recal.

Tim

 

[NorthwestIL]

Hi Peter! Interested too!

 

[retepsnikrep]

What about thresholds based on the amount of current, such as 'increase assist 75% when amps < 50A'?

Remember the ECM requests levels of assist/regen that do not directly/exactly correlate to a certain number of amps, it's a Kw power level req. Also the device has no knowledge of the number of amps/kw that the MCM is allowing.

But yes I suppose when the Kw req is below a certain level then yes it could be boosted by x%.

 

[retepsnikrep]

The first code will allow the power levels requested to be adjusted to +/- 100% on assist/regen. The middle setting on the pots is null no effect.

So if the car is requesting 50 units of assist and you have the assist pot turned right up you will get 100 units (Double assist) and vice versa if you have the assist pot turned right down you will get 0 units (No Assist)

Ditto for regen.

Pots can be adjusted independently, so you could have.

+100% for assist and -100% for regen.

At 50 units of assist you would get 100 units (Double Assist)
At 50 units of regen you would get 0 units. (No Regen)

and vice versa

-100% for assist and +100% for regen.

At 50 units of assist you would get 0 units (No Assist)
At 50 units of regen you would get 100 units. (Double Regen)

 

[eq1]

If Kw could be used by the device as a criterion for activation I think that'd work fine. I'd mainly be trying to boost low kW requests, and either leave the high kW requests as-is or perhaps limit them, were it possible...

I've been thinking about this a bit, and really, my main objective is to get more electric assist without having to get more gas engine power at the same time; it's about having the electric offset more of the ICE power, mostly in the low 1.5-2.5kW range as-is. It'd be better if these were like +50%-125% most of the time I see them requested on the OBDIIC&C...

 

[retepsnikrep]

Eq1. You will have to try the device as is and see how you get on with it.
After evaluation we can then tinker with the code.

Finished Alpha code.

http://youtu.be/e0r-q_1paeM

Simulation running on Proteus.

The maths was a bit hard for me :? but managed it after a few hours.
Seems to work as expected.

Need to knock one up on some breadboard.
Will try it in the wifes car perhaps tomorrow.

Peter

 

[samwichse]

Hey, that PCB looks pretty familiar .

Could you have just reused the hch1 imac&c PCB with no buttons on it?

 

[retepsnikrep]

Could you have just reused the hch1 imac&c PCB with no buttons on it?

Messy This need to be simple to install. No pcb hacking. 4 Wires and away you go.

 

[retepsnikrep]

Seems to work fine.

Knocked it up on some breadboard (pic below) and tried it in wifes car.
Does what it says on the tin. No IMA errors or apparent glitches.

Does not affect IMA start.
Autostop seems to work fine.

Turn assist down to nothing and that's what you get no assist at all!!
Turn assist up and you get all the MCM will give.

Ditto regen.

If you want to build one on breadboard or veroboard now because you can't wait,
let me know and I'll send you the password for the protected hex code.
The pcb's won't be here for a month and I'm away in October.

Ima Boost 002 - YouTube

I put mine in the IPU but it's probably better in the footwell with an old black 4 core usb screened lead to mount it on dash. Drill two holes in the box and you can adjust it with a small screwdriver until you find your sweet spot. OBDIIC&C is pretty much a prerequisite to see the effect of your twiddling is having. Remember the OEM assist/regen gauge is very vague.

It needs only four wires.

5v+ Pin1 J1. ECM Connector C Pin 28 Yel/Blu
CmdPwr In Pin2 J1. From ECM Connector D Pin 8 Blu/Blk Wire cut.
CmdPwr Out Pin3 J1. To MCM Connector D Pin 8 Blu/Blk Wire cut.
Gnd Pin5 J1. ECM Connector C Pin 18 Grn/Blk

If you wanted you could use bigger pots and have finger knobs so you could turn it up and down at will!

The device is no substitute for a new/good battery, grid charging or cycling, but it might allow you a few more months to save up for a new pack. Those with good packs will enjoy the boosted assist.

I suppose the packs it might help most are those which trigger overheating codes as you can reduce the demands on it to virtually nothing. It might help others with low capacity or other issues but you will have to try it and see.

Turn assist to very low/zero then turn regen/background charge down to say 25% of it's current value to keep the dodgy pack topped up with sufficient for autostop and ima start.

The device does not override any OEM safeties and the MCM/BCM will still cut back your demands if you go mad!

I better get back to work on the Simple Cycler and the Voltage Tap Display!

 

[retepsnikrep]

Final Revison?

To accommodate future requests, I have just made a couple of final revisions to the schematic.
This free's up a useful Pic pin and I/O port with analog capability if reqd.

Could be used for a number of things, but these are what I thought of. :?

1) Temporarily/Permanently attach a serial lcd display for setting/monitoring assist/regen pot % values.
2) Use it as a button input for an IMA rally mode. Like a KERS switch/button.
3) Use it for analog input from TPS, MAP or whatever.

Please remember with this very simple and cheap device the assist and regen can only be
adjusted, modified or boosted (increased/decreased) if the ECM is calling for them.

If the ECM is not calling for either then the device does nothing.
It does not control enough signals to perform the full functions of MIMA or IMAC&C.
You need MIMA or IMAC&C to take full control of the IMA system.
It's designed primarily as an IMA battery protector.

It's eventual functionality is limited only by the simple hardware constraints, our ideas and imagination.

 

[eq1]

For how simple it is (it seems), seems like it might deliver a disproportionate amount of fun, use, especially in conjunction with the OBDIIC&C. I was thinking that, for starters, it would be great to try to dial-up assist enough that the knock sensor doesn't become active at modest throttle, everyday acceleration...