Rebuilding a Battery Pack

6057 Views 17 Replies 12 Participants Last post by james, Jul 16, 2007

gobuchul74

Discussion Starter · Apr 28, 2005

Well my Insight's battery finally bit the dust. I bought it used with 80K miles and it never seemed quite right. Now at 121K miles the IMA chrg/assist is gone, the IMA light is constant and the Check Eng light is constant. The OBDII codes I've read are 1447 and 1449. I've found that the 1447 code is something about the battery being degraded and I still don't know what 1449 is, but I can guess.

Has anyone ever contemplated rebuilding the battery pack themselves, or seen a website that has any information about it? I've found a used battery pack for $1500, but I don't need to spend that kind of money right now. I will at least take a look at the battery myself and see how feasible a rebuild would be.

What concerns me the most are the individual cells in the battery pack. Has anyone taken a good look at these and could you tell me if they are basically your average D-cell or are they some type of proprietary setup. I think they might have threaded connectors, and if thats true then its over.

Thanks.

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Insightful Trekker

· #2 · Apr 28, 2005

Photos here:

http://pages.cthome.net/genesisone/insi ... xposed.htm

Home built has not been tried yet. Your quote for a used pack is high. Last time I checked (Sept. 2004) a new IMA pack is about $2100 installed. Estimate for OEM "bare" batteries from Panasonic is $900. No established source yet.

Maybe you'd be interested in trying the MIMA experimental project. Its a long thread, but worth the read if your game to try some "upgraded" batteries.

Link here:

http://www.insightcentral.net/forum/vie ... php?t=2471

HTH!

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Rick

· #3 · Apr 29, 2005

Try HAP auto recycling, they've got a couple of Insight's they part out.

http://www.haprecycling.com/

b1shmu63

· #4 · Apr 29, 2005

The batteries in the Insight pack have a lower Ampere hour rating than consumer grade batteries, presumably because the electrodes are thicker to allow larger surge currents without the individual cells heating up. The cells are spot welded together into sub assemblies with bolt holes on each end. To withstand the surge current a home brew battery would have to be larger capacity with more cells.

Billy

· #5 · Apr 29, 2005

I STILL don't see why someone has not tackled this yet.........First, there is NO technical reason to replace any component except the 120 batteries (unless you have no choice but the buy the whole package as a whole) Can't someone find Panasonic NiMH D cell, 6.5AH batteries? Recently I priced them, and it looks like the total would be about $720. Then the challenge would just be to attach them in pairs or in groups of six, or whatever it is. If someone would try this, it would be a huge help to MANY Insight owners!! Rick from AZ, what do you think?? Bottom line: it would be fantastic to make these batteries USER REPLACEABLE! Billy....

JustinGray

· #6 · Apr 29, 2005

how did you price them. From where.

I would be willing to do some research into how to make our own battery strings. 720 dollars for battery replacement is much much cheaper than stock.

All we would need to do is figure out a way to attach the batteries in series with eachother, then attach those threaded nuts to each end, glue on the battery temp sensor, and we are good to go!

would 120 of these work? http://cgi.ebay.com.au/ws/eBayISAPI.dll ... 7510581228

seriously though, what are the exaxt specs on these batteries... perhaps we can find some non panasonic battery that is cheaper!

Justin

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Billy

· #7 · Apr 29, 2005

Hi Justin; yeah, those might work if they are 6.5 ah but i cannot tell from the picture or description. A short while back I did a google search for panasonic NiMH batteries, and saw several possible sources. However, I could not determine who had them ready to sell for retail delivery. Actually the price might be BELOW $720, because rather than 6 bucks apiece they may be only 4.50 or so. Radio Shack has some very similar batteries, but the ah is only 4.5........ Billy....

Aaron Cake

· #8 · Apr 30, 2005

As has been posted many times before,

the Insight's batteries are NOT off the shelf consumer Ni-MH. The most important difference are the terminals. The Insight's batteries are built with bolts/nuts as terminals, not the plates that consumber batteries use. This is because each cell needs to pass currents of up to 100A or so, and regular terminals would vaporize.

Rick

· #9 · May 1, 2005

The problem is the cell's you priced from Panasonic are not the same battery. They're the ones with solder terminals. I've tried getting information from Panasonic and their only response was contact the oem. I just wanted to buy one stick so I could show people what they look like.

*If* you could get the screw terminal batteries it would be a project someone with enough mechanical and electrical experience could do. It would take some time to remove all the components that are on top of the pack and then dissassemble the caseing, then you'd have to put the temperature sensors back in and it could be done. The other consideration is you'd have to have adequate electrical knowledge to know how not to get a nasty shock. I would personally feel comfortable doing it, but if you didn't know what your looking at it's not something you'd want to learn in an Insight.

You simply cannot just use off the shelf batteries. The D cell size is decieving I guess. Panasonic specifically makes batteries for the Hybrid application that can handle large currents. I mean I tried pulling 4 amps out of some parralleled AA batteries in a small spot light and they got so hot they melted the plastic holders I had them in.

What I would do personally if I could get whatever batteries I needed would be to get some Prismatic cells like Toyota uses because they're designed for even higher current draws. These are the same 6.5 ah capacity so it would interface with the existing electronics. Again the problem is they only sell to OEM's.

Don't try building your own pack out of solder tab batteries. I guarantee you it will earn you the name plasma boy/girl. And that's if you could even get them to move that much current.

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dberns

· #10 · Jul 8, 2007

has anyone built one yet?

I've got a contact at an independent battery shop that's been making (lots and lots and lots) of radio and plenty of other battery packs for a couple of decades.

He's willing to think about the Insight.

Before we go further, has anyone followed up on the earlier discussions and pt one together?

thanks

Insightful Trekker

· #11 · Jul 8, 2007

IIRC Calpod tried it with used batteries swapped out from a different IMA pack. He also attempted to evaluate the condition of each stick before proceeding. However, he apparently did _not_ have a sufficiently high enough charge / discharge load for accurate evaluation. His refurbished pack project was abandon ( :?: )

Welding new individual batteries into a stick has not yet been attempted.

DaveW

· #12 · Jul 8, 2007

dberns I have been interested in looking into finding some cells and being able to rebuild our packs. I own Leading Edge RC cars, I cut graphite for RC oval racing chassis and have been in the battery matching business as well. I have been matching batteries (nicads and nickel metal) for 20 years. I feel that there are a number of companies out there now that offer cells that are much better than the Panasonics that we have now.

I think the pack in my car is bad right now, I just bought a used pack that should be here tomorrow. After I have it installed I am going to open up my old pack and look into a way to replace the cells.

Through my battery matching business I have hooked up with a local shop that rebuilds and sells packs for cordless drills. Over the past few years I have sold them many cases of cells for cordless drill pack rebuilding. We as RC racers only use the very top percentage of cells for racing. After we run the new cells through the matchers we will only use the very best ones, then we sell the lower grade ones off to be used for other things. I have a very good relationship with this shop and they have the ability to spot weld cells together.

I will keep everyone posted on what I find out.

Dave

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Insightful Trekker

· #13 · Jul 8, 2007

Nope think is was gobuchul74 here:

Replacing IMA Pack Cells
http://www.insightcentral.net/forum/vie ... sc&start=0

HTH!

Mike Dabrowski 2000

· #14 · Jul 13, 2007

My 120K pack is still behaving pretty well, even with the heavy use it gets in my setup, but I am looking down the road, and figure that instead of trying to just put NIMH back into the pack, why not source some high rate of discharge
Li batteries, and just gut the battery case, and build a custom pack with much higher capacity. I have a plan that should work to fool the BCM into thinking that the pack is of stock capacity and properly manage the new pack.
I have to get a "bad" Insight pack that I can carefully pull the cells out of to give this a shot, so if anyone runs into one for not a lot of money, let me know, and I can put this project on the bench.

Dougie

· #15 · Jul 14, 2007

I finally got around to asking my friend who works at a battery company about all this, and after talking to somebody who actually knows something about batteries, I'm not so optimistic about home-brew pack rebuilding as I was.

First, the connections between the cells are spot welded using special equipment, and soldering isn't a suitable replacement because the lead introduces too much resistance. Second, the cells must be matched, and the matching is a big, big deal that accounts for a considerable fraction of the pack cost.

My new view on this topic is that the battery packs are sold at a loss, or at least not at much of a profit, just like the Insight car itself.

james

· #16 · Jul 15, 2007

Mike, did you ever get anywhere with the idea of building replacement/larger packs out of used Prius cells?

Mike Dabrowski 2000

· #17 · Jul 16, 2007

Not far, I have this tendency to get drawn into new projects faster than I can finish the old ones.
I really want to increase the capacity if I am going to design a new battery management system, and The prius subpacks have the same capacity as the Insight ones, therefore a switch to LI would give us higher capacity for the same weight.
The Prius subpacks are proving to be quite tough, and as I use them I am learning how to charge them. I am using them for all sorts of projects.

IamIan has moved into the area, and has been over twice helping out with various projects, so with his help, we may get back into the batterys soon.

james

· #18 · Jul 16, 2007

"Not far, I have this tendency to get drawn into new projects faster than I can finish the old ones."

Yes, I can relate to that.

Though it's gotten to where I don't really want a bigger battery pack, I want a nice carbon-fiber flywheel arrangement instead. All I need is maybe $100K in machine tools, and the time and experience to use them properly

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