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Radio shack sells 1.2 volt NiMH "D" cells. 120 would cost $1,020. Is it possible to replace these within the battery pack? If not could one easily replace the entire battery pack with another say from a junk yard? I understand they run about $800? Or is this a job for Honda.
I am running fine at the moment, but someday........
Rusty
 

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Sorry, I did a search and it did not come up near the top so I took a chance. I should have known it would be a hot topic though. Also the Radio Shacks are only rated at 4500mAh. But I will be putting on a lot of miles so I was just thinking ahead. I doubt they will last 350000 to 400000 miles or 11 years.
Rusty
 

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The Insight Batteries are Industrial VERY High Amp Drain rates... up to 80 Amps from a single D Cell.

Even if you were going to do this.

Radio Shack D Cell NiMH aren't worth buying.

Radio Shack $16.99 for a 2 pack of 4500 mAh
1.2V x 4.5Ah ~5.4 Watt per cell x2 pack ~10.8 Watts/16.99 ~ 0.63 W/$
120 Cell / 2 = 60 packs of 2 x 16.99 = $1,019.40 for ~648 Wh

Overstock.com Has $19.50 for a 2 pack of 12000 mAh D cell NiMH
1.2V x 12Ah ~14.4 Watt per cell x2 pack ~28.8 Watts/19.50 ~ 1.47 W/$
120 Cell / 2 = 60 packs of 2 x 19.50 = $1,170.00 for ~1,728 Wh

or $151 dollars or ~13% more for ~167% More Power.

Of course you can get much less expensive NiMH D cells if you just want the cheapest you can get... but ultimately for the Insight you need D cells that can handel 80 Amps .... Very Few Can.... it is like ~12 times the Battery Capacity as a discharge rate or ~12C.

I use the 12000 mAh NiMH D Cells in a 30 cell 36 Volt Battery Pack I made up for my Electric Assist Pedal Bike that drawls at peak 20 Amp... They handel this ~1.6C discharge rate without any thermal management really needed and the company that makes them says they can handel repeated use at up to 25 Amp rate ( or ~2C ) without any long term damage, more than this and they recomend having a rigorous battery management system.... to get 80 Amps would be a 6.6C rate more than 3 times the recomended normal rate.... 80 Amps is just allot of Amps....

You would also have to break apart a Insight battery pack to get all the sensors and such that you need for the car to use the pack ...

Oh and it is over 144Volts .... This high of voltage CAN KILL YOU.

my 2 bits.

but good thought anyway.
 

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All that aside, it's also a question whether the battery management computer would work right. It's trying to keep the batteries partially charged all the time, so presumably there are various constants in the programming that would not line up with the replacement batteries...
 

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Dougie said:
All that aside, it's also a question whether the battery management computer would work right. It's trying to keep the batteries partially charged all the time, so presumably there are various constants in the programming that would not line up with the replacement batteries...
As long as your working with NiMH's and the capacity of the pack is the same or greater than you'll be fine. If you "oversize" the capacity of the pack it probably won't be utilized by the existing software.

Again the _biggest_ "problem" is the high capacity discharge rate requirement. _ANY_ battery not up to this task _will_ rapidly weaken and fail. The only "easy" workaround would be to disable the IMA starter, install MIMA and limit the IMA's loads to within the installed batteries capacity.

HTH! :)
 

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gobuchul74 was nice enough to send me the old Insight pack that he was trying to rebuild for only the price of shipping.Thanks ED.

I can fit 144V of prius batteries inside the case if I do a bit of hacking and make a new air handling system. My first impressions are that it could be made to work as a replacement for our D cells in the same form factor. Unfortunately the subpacks and temp probes for the Insight pack were already removed, so I can not use them to duplicate the temp circuitry and try it.
The prius pack has the same number of subpacks, and the same capacity cells, so the voltage taps could be moved from the old pack to the prius based one. The temp sensors could also be made to work. The biggest chalange will be to run the cooling air through the prius subpacks. The rectangular prius subpacks with the flat sides tend to bulge out when near the end of charge, so in the prius pack, they are held between two reinforced metal plates and are clamped quite tightly, so a similar clamping arrangement would need to be designed. The existing relay current sensor assembly can also be used, with a bit of wiring . In my non existent spare time, I will be building up my replacement pack, so I will be ready when it finally goes bad.
 

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I don't think I've ever had my assist gauge all the way over to the end. Well, maybe once or twice as an experiment, but during normal driving--even on the long steep hill in my commute--I never go past half-way. So depending on driving habits it might be ok to have less than full current draw capability.

On the other hand, I frequently have full assist showing...

Another idea would be to incorporate an add-on circuit to limit the assist current.
 

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Dougie wrote:
Another idea would be to incorporate an add-on circuit to limit the assist current.
I posted on such a circuit a while back, see "how to disable assist/regen" on Modifications thread.[/url]
 

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Even 1/2 current is 50A. The terminals need to be big enough to not heat up with that draw. Buy some cells, and build a mock up, and run some high current test. You will probably want to get at least 6 cells to simulate an Insight subpack. Although making two subpacks for a 14V pack would let you use auto headlights or other auto components for your load. Then you will have your answer.
I have a plan on how one could "fool" the SOC meter into properly measuring and maintaining the proper charge for a larger AH pack.I have not tried it yet, but in theory it should work.
Contact the cell manufacturer and get a spec on the maximum discharge that the cell can produce.
Larger capacity cells that can supply the current would be the best fix for a dead IMA battery.
:wink:
 

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Radio shack sells 1.2 volt NiMH "D" cells. 120 would cost $1,020. Is it possible to replace these within the battery pack? If not could one easily replace the entire battery pack with another say from a junk yard? I understand they run about $800? Or is this a job for Honda.
I am running fine at the moment, but someday........
Rusty
If you're like me, you tend to keep a given car for a while; i.e., ten years or so. That 95 Ford Taurus proved to be a great car, almost as good as the 220D Mercedes I used to have, so if you plan to keep the car for a while, I suggest that like the tires and mirrors, Honda doesn't make those NiMH batteries. Someone else does and Honda buys from them.

Odds are that more than one manufacturer of these batteries exists and when the time comes, and if you're sufficiently skilled, odds are it just might be far less expensive to buy a new NiMH battery from one of the manufacturers than from Honda.

Now, how many battery manufacturers are there in America, who make NiMH batteries that can (or can be made to) fit in the Insight?

If you're interested in batteries there is a very good introduction page regarding batteries; introduction, design, maintenance, etc. Done by a German fellow; can't for the life of me think of the www address at the moment but the page is very well done!

Fred
 

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The RadioShack D cells would not be able to handel the 80 Amps charging or 80 Amp Discharging per cell rates that the Honda cells do.... But if you put them in the Honda Electronics would try to force them to handel it... which would cause the RadioShack cells to over heat quickly... and at best die rather quickly.... at worst they would explode.

The Radio Shack D cells are not even particularly good priced or powered NiMH D cells.... there are far cheaper on the web without even looking very hard... and there are far better.... I use 12,000 mAh NiMH D cells from overstock.com in my Electric Assist Bike... But these are only rated for up to ~24 Amp rates.. I only use them up to 20 Amp rates peek in the bike...

The key is that they will not handel the ~80 Amp rates that the Insight D cells are put through on a regular basis every time you do a full assist acceleration.

If in Doubt bug the radio shack people to get you the data sheet for thier D cell batteries... I worked for Radio Shack ~2 years ago and they had the sheets by fax then... but if I recall they were not even 10 Amp rates but feel free to check with them to get the battery data sheet to see what thier max discahrge and charge rates are.... I seriously doubt they can handel anything like ~80 Amps.
 

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The Insight cells fit into removable holders within the battery case.
Remove the holders, and you have a rectangular case. Cut out two of the dividers, and you have an open box that will fit 20 of the Prius subpacks.
Prius NIMH subpacks should be able to replace the Insight subpacks, and if disassembled carefully, the thermal sensors, and voltage taps should be reusable. The advantage here is the large number of Prius that should be available for canibalizing, the built in heavy duty contacts on subpacks designed for similar load, and the same AH rating on the batterys so the SOC meter should accurately tell the SOC.
The only issue that will need work is the cooling air flow will need to be completely redone, and the Prius subpacks must ne clamped between two metal plates to properly contain the internal pressure during the charge.
I will do it on mine when the main pack gives up.

:wink:
 

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good to know mike thanks....

especially if a prius is in a junk yard from a accident but the battery pack escaped the accident unharmed....

There are several junk yards that how crashed insights with head on collisions.... the rear stuff should all be intact... If I ever have that much spare cash maybe I will buy a junked Insight just to mess with and test ideas on.... Don't need it to be road worthy or even pretty it would just be a test mule.

.... Even to just test on some of the electronics would be useful.... oh well... when I have more money to trough at it.
 
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