[countchocula]

Thanks to everyone who responded to my previous post about replacing the Insight battery pack with the HCH pack. Judging by your responses, it seems this wouldn't be cost effective.

So, how about disabling the IMA all together and just running the car with the ICE? I know this would take some modifications, but is it do-able for a cost substantially less than the cost of a new battery pack?

I'm asking these questions, not because I am planning on doing this any time soon, but because I think the cost of a replacement pack will inevitably end up being too much for some of us, so I'm trying to find alternatives to it that would make the car useful for a while longer after the battery pack buys the farm.

BTW, how do you test the Individual cells in the Battery Pack? This would be useful to know for those of us who consider buying a used pack from a junkyard.

 

[Foxpaw]

You should be able to do this fairly easily - to my knowledge just removing the fuse for the IMA system does the same thing. Then you could just remove whatever you didn't need. (Might not hurt to try disabling the IMA light that's going to come on, too.) The actual IMA motor you probrably need, since it's armature serves as the flywheel.

Actually, however, you would then have no alternator, so you'd run out of battery. It might be possible to "hardwire" the IMA motor to a certain amount of regen to have it serve as an alternator, however.

One thing to consider, however, is that the Insight will likely be severely gutless (probrably just shy of VW's "1 litre" car) without the IMA.

 

[Insightful Trekker]

There are numerous technical hurdles to jump.

As Foxpaw pointed out you'd have no alternator function and the 12v battery would be dead in just a few miles.

Rigging the IMA motor as an alternator is the most elegant and most difficult, its AC voltage that must be rectified to DC, reduced from 140 to 12v and the current must then be regulated.

The likely lower cost option would be to fabricate a bracket and hang an off-the- shelf alternator to be driven by the serpentine belt.

Fairly big bucks either way, but the hang on alternator is probably much lower cost then an IMA battery pack. The use of the IMA motor as an alternator has many technical challenges that do not have an off the shelf solution.

And you would be driving a gutless wonder.

Boy are you full of a lot of IMA battery cost avoidance questions! <g> Too much high sugar breakfast food?

I don't like the thought of the cost either and am planning to try battery cell replacement when the time comes. (Years from now by my warranty expiration mileage / date).

Testing the individual cells requires a specific charging, loading and timing device. You will also need to be able to accurately measure the voltage to the nearest 100th of a volt (an accurate digital volt meter). Then you simply charge the stick to "full" load it a specific amount and by time as determined by the sticks capacity and read its final voltage.

A used IMA pack is probably the worst choice vs. new OEM off the shelf sticks.

HTH!

 

[Foxpaw]

Ah. A serpentine belt driven alternator would be better. Since there's no alternator, I had assumed there wouldn't be a crank pulley on the front of the engine, but now that you mention it I guess there would be one for the A/C and power steering.

 

[dan]

The power steering is electric (12v). I assumed this was to help facilitate start up after idle stop mode although the encyclopedia does not mention this reason in particular.

 

[Yves M.]

Hi,

I seems to me that it would be simpler to replace the batteries with similar capacitors.

I do not remember but for example, if the batteries are in packs of 12 (12v per modules) I would simply put 12v capacitors(or a little higher) to allow the BCM sensors to continue there work.

I would not expect the IMA to be able to give much assist but it would make it work for the 144v/12v converter. Would probably always charge, but would charge quickly.

 

[cakley]

I had read somewhere that an Insight owner shut off the main battery and the car worked OK.

I wouldn't think it would cost that much at all to have a bracket made to install a one wire GM alternator. All it would take is some time and effort. The person who made the bracket would be able to sell it to other Insight owners...

Another option would be a Optima Yellow top battery. Along with a battery tender wired in for solar charging. And plugged in over night. Due a google search for "battery tender". I use a battery tender for my motorcycle in the winter down time. The yellow top battery are the deep cycle kind that are used in heavy duty engines.

_ Performance would be OK as long as the car gets driven like most little 4cyl. RUN THE RPMS> Plus the main battery weight could be removed.

 

[Holicow]

I don't think it would matter what brand of battery you have, it won't last long running the ignition and everything else in the car.

I think the grafted alternator is the only way to do this....

 

[b1shmu63]

Lithium batteries would work as long as their amp hour rating and overall voltage was exactly the same. Super caps would work only if the Computer could be reprogrammed, as the voltage on a capacitor falls linearly with decreasing charge whereas a battery holds almost the same voltage untill it is almost discharged. The difference would confuse the computer and produce continuous error codes. Lead batteries would work but would at best only last a few hundred cycles ( a British consortium is working on this idea)

 

[Armin]

Lithium batteries would work as long as their amp hour rating and overall voltage was exactly the same.

No they won't!

In fact, replacing a NiMH with Lithium is a very dangerous thing to do! The power density of lithium is much lower than NiHM. The way the two systems get charged is significantly different: Most lithium batteries need to get topped off very carefully with a constant-voltage charge at fairly small current. NiMH uses constant current. The Insight pushes current peaks of up to 50 Amps into the batteries. A 6.5 Ah lithium cell will not survive this!

Using a charger meant for NiMH on a Lithium battery will almost certainly overheat it, if not cause it to explode!

Be careful out there!

 

[b1shmu63]

Armin, you are correct. I was assuming that we were talking about a new generation of Lithium batteries that are currently being developed for hybrid applications and also assumed that they would have similar current characteristics. Using any other type of Lithium cell would be extremely risky (as I have suggested in other posts). One company currently developing a Litium automotive battery is addressing the current, fire and toxic gas issues.

NmH batteries are the only batteries that can be disposed of as non hazardous waste. This is an important consideration if you are concerned about the environment.