CR-Z lithium battery swap

[jasongullickson]

Good evening folks;

I purchased a CR-Z as a sucessor to my (totaled) first-gen Insight. I'm interested in the possibility of replacing the nimh battery with some flavor of li-ion pack to either reduce weight, increase capacity or perhaps both.

I had read extensively about such modifications to Insights on this forum and I'm wondering if anyone here could shed some light on what it would take to perform a similar operation on my CR-Z?


Jason

[Purplegate]

I'm surely not the expert for battery stuff, but with the CR-Z, you will hit the same problem we have with the Gen2 insight : you will have to gain control over the CAN Bus, on top of other BCM and all electical controls, which was a bit easier with the Gen1 Insight.

However, my first question would be : Why do you want to put a lithium battery in the CR-Z ?

If it's to get EV capabilities, you would be in much better position with a MIMA system. If not, the architecture and control on the hybrid from Honda will not allow you to get full benefit of a lithium pack.

For the pack itself, Peter has made several nice attempts (you can browse in older posts), but his A123 pack is probably the sweetest (in my opinion). Not sure if the OEM pack size in the CR-Z, or th Insight2, would have proper dimensions to accept the A123 cells, but if it does, it could be a great possibility.

Other possibility, Engineer claims they also have a pack that fits the Insight2. It might go also in the CR-Z as I think both cars share the same pack (to be confirmed....).

But bottom line, the problem is not really the battery pack itself, but much more the control you need to get over the whole system. Which is not yet a resolved task...

[jasongullickson]

Originally Posted by Purplegate

However, my first question would be : Why do you want to put a lithium battery in the CR-Z ?

My primary objective is to reduce weight; if I can replace the stock nimh pack with a li-ion one with equal capacity but less weight that would be satisfactory.

As a "phase II" I'd like to see about manipulating the system to improve performance, perhaps by adding additional battery capacity, but my first thought is simply to use this as a way to save some weight.

[MN Driver]

You would save about 32 pounds(in 84 cells) and add plenty of cost to the car. Most of the weight is actually in the motor and control electronics that manage the power going through the motor and make sure the battery is healthy. To go along with that there is quite a bit of structure in the form of fairly dense plastics that are designed to keep the batteries safe in a crash as well.

I don't think that weight savings is a very good reason for switching out 32 pounds of NiMh with Lithium in this car. As mentioned above, without modifications(which don't yet exist for the Gen 2 Insight, Civic Hybrids, or CRZ), the extra capacity, if any, couldn't be used.

[jasongullickson]

Thanks for the specifics. You're right that it would be an expensive way to shed 32lbs (perhaps I should just lay off the soda for awhile) but it's good to know that, at least for the reason of weight alone, I might want to start elsewhere.

That said I'm definitely interested in the work to go further with modifying the electrical side of the car to increase performance. Do you know if the work to hack the can network of the Insight 2 applies to the CR-Z as well?

Thanks again!

[MN Driver]

"Do you know if the work to hack the can network of the Insight 2 applies to the CR-Z as well?"

Hopefully! ...but it's hard to say. You would think that they would be the same or at least similar enough to make an easy adaptation. Time will tell though.

[jasongullickson]

I'd like to take a stab at it, what do I need to get started?

I'm pretty comfortable with hardware and software (both big computers and microcontrollers) but I'm not sure what gear is needed to jack into the car's systems.

[retepsnikrep]

Some sort of canbus interceptor and analyser to record data and compare it with known events related to all the IMA functions. We know how a lot of the IMA messages work on the I1 and we know some of the BCM messages so that's a start point. You need to get yourself the full workshop manual for the car and have a good long read. The manuals are very good and the workshop bulletins are also excellent and contain loads of useful info.

Once you have an idea about what the data means then you need to build an interceptor that sits between the ECM equivalent and the MCM equivalent in the CRZ which can manipulate it on the fly to whatever we require to gain manual control over the system without causing errors.

I'm sure a lot of the CRZ stuff will be directly relevant to the I2 and vice versa. So one system may suit both cars

[jasongullickson]

Originally Posted by retepsnikrep

Some sort of canbus interceptor and analyser...

Yes, what is that exactly? Is this something like a scangauge that plugs into the odbii port (is that the right term?) or are we talking about tapping the leads and building a signal analyzer from scratch?

Sorry if these are silly questions, I'm just not familiar with modern car electronics.

[retepsnikrep]

I think you will find there are commerical packages software/units avaialble, have a go on google. You will need to tap in directly to the wiring between the various modules to listen to the data comms and reverse engineer it. I've never looked at canbus but the internet is your oyster.