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Discussion Starter · #1 · (Edited)
For general Lithium conversion/upgrade battery chat please use this thread.

To avoid the growing thread about my personal CRZ conversion from Nimh to Lithium getting bogged down in battery discussions
lets have this seperate thread just for that, to discuss battery options and ideas.


For reference my conversion thread is here

To get the ball rolling on this one I will repeat a bit of info from the other thread.

I am using ex Honda FIT EV LTO 20ah cells for my prototype Nimh to Lithium CRZ conversion as I had them handy and they meet the criteria.
You of course can use whatever Lithium cells you want as long as they meet the minimum current/voltage handling specifications.


These are a few recommendations based on my long experience with Lithium, EV's and IMA conversions.

1) Use a safe Lithium chemistry. Not all Lithium batteries are naturally safe or rugged.
Don't be tempted to use LiPo unless you are an expert.
Yes they are powerful and light, but unless managed with a very good BMS they are flaky.
We have all seen pictures/videos of cheap scooters and the odd phone in flames.
Choose wisely and choose once. IMO Lifepo4 and Lto are good conversion candidates.

2) Don't underestimate the punishment and stress the car will inflict on cells.
The OEM Nimh cells are incredibly rugged, long lived and robust with a +125A assist and +70A charge capability.
It's remarkable they work as well as they do, but Panasonic really knew how to make them.

Any Lithium cells you choose must be at least on par if not better than the OEM cells as far as electrical properties are concerned.
Don't always believe exaggerated data sheet performance claims and numbers. Find some cells with real world hard data to back claims up.
If the cells you choose are at all marginal the car will punish you by killing them in a short time and possibly burning it down.

3) A BMS (Battery management system) is a tricky problem.
The LTO blocks luckily don't seem to need much managing/balancing, but other chemistries may need a lot.
I use my own systems to manage the LTO packs, you will have to research options very carefully.

Do not get any sort of BMS that has built in mosfets to cut power etc. This is common with cheap bike packs and the like.
They are fine for your scooter, but if any BMS cuts the main power directly you will get an immediate IMA fault and possibly damage the inverter.
Any BMS you get has to communicate with the car properly and allow the car to shut things down in it's own controlled way.

4) Don't underestimate the time, effort, skills and money it will take to do a conversion to Lithium.
Unless you have all the skills and parts already you will need fairly deep pockets to get everything required and then pay someone to do it.
Messing around with high voltage isn't cheap or easy, and a lithium conversion will never likely save you money in pure mpg terms.
Of course you will be able to follow my video guides and posts, but you still need all the other stuff above.

I bought a second pack so I could do the mods and research on the bench in advance of the actual fitting.

5) Mods and OEM warranties do not go hand in hand. Honda are not going to fix your blown $3000 IMA if you mess up or it all goes wrong.
Do not undertake or get involved in any IMA modding except under the express understanding that you could break the car and lose your money.

6) Why do it then? Well if you like performance, the CRZ certainly does look sporty, and goes reasonably well.
But a lot of us crave a bit more oomph, or at least would like to be on par with our lucky OEM Lithium CRZ brethren.

This video from yesterday shows a few options and ideas.

 

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BOOSTING PERFORMANCE WITH AN ADD-ON BOOSTER BATTERY/BATTERIES
My car is a 2013 facelift model with Lithium batteries.
I've had a brainwave but you'll likely shoot me down in flames!
a) I buy three 24V suitable batteries or supercaps.
b) I disconnect the 3, motor phase power cables and insert one battery in each of the 'gaps'.
c) These new batteries are outside the existing system so the MCM is not seeing the extra 24v.
d) The actual motor voltage is now ~180 so more current is driven into it.
e) To stop the MCM spotting the increased current, the current sensing signals are limited (simple analogue circuit) to the normal maximum equivalent to 125a or whatever its is when new.
Might get away with telling the MCM its got new batteries if it's recalibrated itself to a lower max current over the years.

As you said on your main thread, the three batteries would need at least their own temperature sensors and be able to handle the increased charge and discharge current now flowing round the system without protest.
 

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Discussion Starter · #3 ·
FG. I did reply to this one on the other thread, but to add to that.
I don't think you need to hack the current sensors for the initial Y/N tests.

The IMA will not allow more current than it calculated is required for say a commanded 10kw output at it's expected voltages.
It won't allow more than OEM current levels unless you hack the sensors.

Your proof of concept power increase will simply come from the fact the voltage is higher.
If the voltage increase causes a higher current to flow the IMA will likely dial back the PWM to keep it at the level it wanted.

Another issue for you if you hack the current sensors by X% is it will throw out the MCM Ah counting and SOC management of your tiny OEM Lithium pack by X%.

That SOC counting is not critical in my setup as I have 20ah capacity in my LTO blocks so I get away with it.
 

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I was thinking of not hacking the current sensor by x% but to limit the signal to the normal max so the increased current will not increase the current sensor signal and so the MCM is non the wiser.
How easy is it to access the current sensing resistors i wonder.
I've just realised this idea is a non starter because the motor is an AC type so a battery cannot be inserted into the phase connections because it won't like the AC.

So back to your idea of inserting one battery in the main battery output (at the battery mains switch)
 

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Discussion Starter · #5 ·
Your SOC counting will be out if you fake the current sensors in any way.

The CRZ current sensors are voltage output devices asfaik and don't rely on a traditional 4-20ma style current loop.

AC hmm.
 

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Discussion Starter · #6 · (Edited)
I posed the question/idea about the extra batteries in the phase wires on the Insight Central forum

I know the IMA systems pretty well and have a reasonable amateur knowledge of electronics and PIC programming. But.....
I'm an amoeba in comparison to a few long standing members (Geniuses) on that forum.

They have a much better full time professional in depth grasp on electronics and motor theory.
They probably wear starched white coats, build rockets and stuff, or work for discrete government agencies hacking the bad guys.

This was the first 'Boss Level' reply..


There may well be others in due course when they emerge into the daylight from their secret research laboratories at Area 51 :alien:..
 

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Discussion Starter · #7 · (Edited)
Formulating a longer term V3 plan for a spring 2021 upgrade.

I am leaning towards making a compact lighter pack using A123 20ah pouch cells for a few reasons.

1) I've used them extensively before, know they work well, and can take the high regen and assist currents.
2) They are reasonably thin and light.
3) They are available pretty cheaply on AliExpress etc. ~$800/£600 for 35 cells including shipping.
4) 35 cells would probably make a good test pack for the CRZ in terms of standard OEM voltage compatibility.
5) 35 divides equally by seven so you would not need a BCM Fooler resistor matrix for standard voltages and could simply connect the OEM Nimh voltage taps every 5 Lithium cells.
6) There are a variety of BMS solutions available.
7) It might well be possible to fit them in the OEM space.
8) I have a load of old ones here to make various dummy packs for fitting tests.

There are lots of attractive looking Lithium options out there, but as I have mentioned most simply cannot handle the currents required by the CRZ.

So we have to go bigger in capacity than we really need i.e. A123 20ah.
But a positive side effect of that is the cells will lead a pretty easy life in terms of SOC cycling.
The car will only use ~3.75ah of the available capacity in normal use, so it won't be stressed at the top or bottom of the SOC curve.
We might be able to unlock some of the unused extra capacity later with a sneaky gadget. :cool:

The LTO cells I am fitting at the moment will suffice temporarily to do the current/voltage hacking tests over the next month or two.

 

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My idea was wrong. From the workshop manual:
Motor Power Inverter (MPI) Module
The MPI module converts 100 V DC into 3-phase AC to run the electric motor during assist.
During regeneration, the MPI module converts AC voltage to DC.
The MPI module is air cooled. The heat from the heat sink is exhausted to the cargo area by the IPU module fan.


So inserting a battery into a lead carrying AC is a bad idea, never mind it not doing anything. I think the guys on the Insight forum have overlooked the MPI converting the DC into AC.
In any case, you must not feed DC into an AC motor because it would magnetise the stator, unless it is designed for significant DC current, which vehicle motors aren't.

So an extra battery in series with the existing pack is the way to go for boosting Lithium powered cars.
 

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8 of those Aliexpress pouches would provide about a 25v boost so with your hacks, should give a noticeable torque increase.
 

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Discussion Starter · #10 ·
Another UK Insight enthusiast used BMW Hybrid Lithium cells in his conversion.

BIMSIGHT

Two blocks might be a possible Nimh CRZ conversion.
 

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Joining this thread!! Pretty interesting! Please keep us posted with new findings!! :D
 

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Discussion Starter · #12 · (Edited)
OEM CRZ Lithium Pack Details and Pictures.

62781


With a lot of searching I managed to get quite a few pics of the internal construction of the CRZ Lithium pack.
Unfortunately it looks completely different from the internals for the Nimh CRZ.

I was hoping things like the DC-DC and IPU may have an identical form factor. (Swaps or mods might then have been possible)
But that does not appear to be the case from these pictures if they are correct.

We do now have a searchable part number for a CRZ Lithium pack and it is 1B000-RTW-A74
Searching on this brings up a few hits on e-bay for people who are interested.

As I have previously mentioned the possibility of simply putting a complete CRZ OEM Lithium setup into a Nimh car is very slim due to all the differences.
The messages on the CAN buses will almost certainly be significantly different.

However it may be possible to put the actual battery section from the Lithium pack into the Nimh car and battery space.
The Lithium would work in the same way as the Lithium cells I am using in my hacked Nimh car.

I did do some work on the CRZ Lithium BMS boards a couple of years ago and can read the individual voltages from the pack.

Attached are the 30+ pictures and links in an archive ZIP file that has been renamed to PDF for uploading.

Rename the file to .ZIP after downloading to extract/view it.
 

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Discussion Starter · #13 · (Edited)
Honda Insight ZE2/ZE3 (2010-2014) IMA battery/system = CRZ (2010-2012) Nimh IMA battery/system.

This may be common knowledge, apologies if it is. :unsure: I did a search and found nothing obvious.

Basically the Insight ZE2/ZE3 has an identical IMA system to the CRZ Nimh cars. (y)

So you do not need to restrict yourself to looking for parts from CRZ's to deal with Nimh IMA issues.
Insight G2's are ten a penny in scrapyards and if you need IMA parts are a simple (possibly cheaper) source.

You can possibly simply drop an G2 Insight IMA pack/unit straight into a CRZ. (Minor outer pack cover differences and ducting aside)
(I would double check the main harness connector pinout)

Certainly the main IMA components like the DC-DC, IPU, Battery, Switchboard, Cells, MCM etc are identical.

Anyway here is a zip file of some Insight G2 pack pics. (Note it's not a pdf! Rename to zip when downloaded then extract)
If you look back at the Nimh CRZ IMA teardown photos I have posted previously you will see the ZE2 parts are identical to the CRZ.

By this token of course all the mods I have done to the CRZ Nimh system are equally applicable to the Insight ZE2 setup. :eek:

This info may warrant a separate thread but I will let the mods move it if they want. ;)
 

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Discussion Starter · #14 ·
The Honda Jazz/Fit 2010-2014 Hybrid IMA setup also looks to be similar to the CR-Z if you need electronic IMA components.

Note fan ducting differences so not a direct swap.

62796


62797
 

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Discussion Starter · #15 ·
Incredibly cheap bargain way to build a Lithium CR-Z pack! (y)

63281


NEW! CASE WITH 2x 12s + 2x 18s HONDA INSIGHT MODULES

Somebody in the US with a dicky/old Nimh setup should def get a set for testing/evaluation.

One set of 4 packs for $400 would build 2x30S CRZ car packs!!!

$200 dollars to upgrade your car!!!!

You would only need a BCM Fooler resistor matrix and you would be good to go!!!
I'll send one free to the first person to dive in and buy a set to upgrade their Nimh CR-Z and document it on here!!

If you find out the BMS plug source/type you can buy a socket and make up a plugin tester or balancer.
Maybe they won't need much looking after.
You might get away with simply watching the total pack voltage with an OBDIIC&C.

I wish these were available in the UK... :(
 

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Discussion Starter · #17 ·
I work for shipping company. I'll drop them an email and see if they agree to ship it here.
If they do then depending on cost I might take a set.

Don't forget we will get stung in the UK for VAT and import duty on top of the combined purchase and shipping price. :cry:

Could easily be $1000 dollars a set over here.
 

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If they do then depending on cost I might take a set.

Don't forget we will get stung in the UK for VAT and import duty on top of the combined purchase and shipping price. :cry:

Could easily be $1000 dollars a set over here.
Vat shouldn't be a problem. It's more to do with duty and shipping as it's Dangerous Goods so will require special permissions. I'm waiting for reply from them about dims and weight, onec I'll get it I will have rough idea about the cost. If you'd be interested making one shipment will lower the cost.
 

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Discussion Starter · #19 · (Edited)
You can probably extrapolate from this and looking at the pic to gauge the rough size of the packing.. ..

THE 12s MODULES ARE ABOUT 4" TALL, 8.5" WIDE, AND 5" DEEP

THE 18S MODULES ARE ABOUT 4" TALL, 13" WIDE, AND 5" DEEP

12S MODULES ARE ROUGHLY 10 LBS AND THE 18S MODULES ARE ROUGHLY 15 LBS.

Just checking I note they might be slightly shorter than the LTO blocks depending on the above measurement accuracy.
It will still be a snug (height) fit under the IPU assembly in the old Nimh battery space.
Some fettling will likely be required along the lines of what I did for LTO and Supercap packs.

I'm def interested in a pack of 4 blocks.
 

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I would certainly be interested in coming in with a group buy & ship if it works out.

I’m not great when it comes to electronics; if there were someone kind enough to assist with the installation and configuration of a pack into my Japanese import ZF1 I would be extremely interested.. There would of course be some of Her Majesty’s finest sterling for the effort!
 
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