Analyzing, refurbishing/repairing a dead hybrid battery pack (2000 Honda Insight)

[MetroMPG]

Originally Posted by ncc74656m

Obviously though, a great deal of your savings came from pure luck, I suspect

Absolutely. Pure luck! I wasn't looking, and didn't expect to buy this one. But couldn't pass it up after I asked the price, just on a whim.

Even the previous owners didn't know what the car was worth. I found out later they traded it in for 500 bucks (thought that's not what I paid for it). Heck, 500 bucks is probably less than the aluminum scrap value. Way less than its parts value.

What, roughly, do the tools you used (Super Brain?) and a Grid Charger cost

My used eBay Super Brain 989 was $80 plus shipping (lucked out - $20-40 more than that seems normal). Add in a few additional computer cooling fans for $??.

Grid charger you can build yourself for roughly $100 - 140 ish (?). Some have made them for less by getting a deal on the four power supply modules needed. You can buy one made by EcoModder / Insightcentral user Artric as well.

If needed, used replacement sticks can be had for roughly $50-100 each from people who have extras, or you can buy your own junkyard battery pack for roughly $400-800 and combine all the best sticks from both packs into one.

not all lot owners would know that a dead batt can be revived like this.

Well the proof is in the pudding. I'd reserve judgment on how successful this has been until after I've tried out this "revived" & balanced pack.

Also, FYI, if you're going to start watching for one... http://ecomodder.com/forum/showthrea...ems-18892.html

[ncc74656m]

Originally Posted by MetroMPG

Absolutely. Pure luck! I wasn't looking, and didn't expect to buy this one. But couldn't pass it up after I asked the price, just on a whim.

Even the previous owners didn't know what the car was worth. I found out later they traded it in for 500 bucks (thought that's not what I paid for it). Heck, 500 bucks is probably less than the aluminum scrap value. Way less than its parts value.

My used eBay Super Brain 989 was $80 plus shipping (lucked out - $20-40 more than that seems normal). Add in a few additional computer cooling fans for $??.

Grid charger you can build yourself for roughly $100 - 140 ish (?). Some have made them for less by getting a deal on the four power supply modules needed. You can buy one made by EcoModder / Insightcentral user Artric as well.

If needed, used replacement sticks can be had for roughly $50-100 each from people who have extras, or you can buy your own junkyard battery pack for roughly $400-800 and combine all the best sticks from both packs into one.

Well the proof is in the pudding. I'd reserve judgment on how successful this has been until after I've tried out this "revived" & balanced pack.

Also, FYI, if you're going to start watching for one... http://ecomodder.com/forum/showthrea...ems-18892.html

And this kind of thing is exactly why I love this forum and your awesome self so much! So much information.

I've had a secret crush on being slow and economical since I saw your Forkenswift. Not really viable for my situation, but still amazing. This kind of project would work really well for me for most of my driving, and it would get me some serious leadfoot rehab.

I'm modding my '06 Corolla right now with some things that will increase performance, but might also do well to keep my fuel consumption in check. My list will definitely include a vacuum gauge because I've heard that's one of the easiest ways to manage fuel use. Eventually, I'll address some of the aero mods I've seen done to help the Corolla be a little more slippery (well, when I don't plan to go out and destroy some gears, anyway).

That green is so out there, too. I've always loved that thing.

[Formula413]

Originally Posted by MetroMPG

In fact, one of the first mods of 2012 for this car will be the clutch switch hack to disable assist on command. I don't plan on using aggressive assist generally.

That's a big one. It's the only mod I have ever done to my car, aside from an occasional grill block. The car will almost always use more assist than can be made up with regen unless you limit it's use. This is also the only way I am able to keep my IMA light from coming on so I can pass inspection. If I left the IMA system alone to do it's thing it will set P1449 within a few miles.

You probably already know this, but when you do this mod it is very advantageous to add a relay powered by the brake switch that bypasses your switch so regen comes back online when you brake.

[IamIan]

Originally Posted by MetroMPG

In fact, one of the first mods of 2012 for this car will be the clutch switch hack to disable assist on command. I don't plan on using aggressive assist generally.

Resistance issues are a double edged sword ... not just assist... but regenerative braking amps also.

Higher resistance values can be 'managed' ... and a pack with higher resistance values can still have considerable service life left ... but it swings both ways ... regenerative braking is the most energy efficient form of braking for any braking you may do... but it will also be part of one's 'management' for a high resistance battery.

You don't have to have 0% assist or regen ... depending on the amount of resistance issue ... if there is an issue at all ... a 10% to 20% reduction in peak power assit and regen , might be sufficient to be able to use that battery for a significant period of time.

[MetroMPG]

Correct me if I'm wrong, but isn't maximum regen current half of maximum assist? (I thought I'd read 50 A vs. 100 A.)

[user removed]

I think the 50-100 is correct, read it somewhere. Thanks for the graph of the pack condition.

I made my CVT battery die to get the dealer to replace the battery under warranty. Used the battery for acceleration the coasted in neutral until it died.

I could always adjust my driving technique to use or avoid the battery but the CVT is more aggressive in battery use, or so it seems.

regards
Mech

regards
Mech

[IamIan]

Originally Posted by MetroMPG

Correct me if I'm wrong, but isn't maximum regen current half of maximum assist? (I thought I'd read 50 A vs. 100 A.)

Yes.
At OEM resistance levels... which are not static by the way ... the Batteries resistance changes under different conditions ... even brand new the batteries resistance changes with different SoC ... even brand new they change at different temperatures ... even brand new discharging resistance is not = to charging resistance.... etc... so there is a range the system is designed to tolerate.

If your pack or cells have higher resistance it applies to any current flow ... in any direction ... the OEM BCM is expecting certain things ... and what it is expecting is already designed for the 50Amps of Regen and 100Amps of Assist... if you have high enough resistance you will eventually be out of that BCM expected range just as much at 50Amps of regenerative braking as you would be at 100Amps of Assist... because the BCM is programed to expect certain things for 50Amps and or 100Amps.

If for example your battery resistance were say ~20% higher Ohms than brand new ...

• That means at any Level of Assist Amps the terminal voltage will read ~20% lower ( V=IR ) than what would be expected from the lower resistance brand new battery ... it will have a larger voltage sag / drop due to the higher resistance under the same load.
• At the same time the same batteries at the same ~20% higher Ohms than brand new would also have ~20% higher Voltage at any given amount of regenerative braking amps ( V=IR ) the higher resistance will create a larger voltage rise from the same amount of charging current.

The way around it is to take advantage of the resistance range built into the BCM to take into account the variation of the resistance under different conditions , even with brand new battery ... so if for higher battery resistance purposes you need to reduce your peak Assist amps by 10% down to ~90Amps you should also equally reduce your peak regen Amps by the same 10% amount down to ~45Amps... etc... as far as resistance goes ... duration or frequency of Assist or Regen is less important than the Peak Current Flow amount of Amps.

[Formula413]

How do you adjust assist and regen amperage?

[IamIan]

Originally Posted by Formula413

How do you adjust assist and regen amperage?

There are several options ... off the top of my head:

• Slight Changes to driving methods / choices:
  • It can be adjusted manually by the driver driving slightly differently ... the dash IMA power indicator does a poor job of indicating the amount of current being discharged out of or charged into the IMA battery ... it can be used but it omits things and is not particularly accurate ... it was designed to give the basic concept to people not for accuracy.
  • A better way to be able to manually make slight modifications to one's driving for this particular effect would be to install a mod that allows you to more accurately watch the the current flowing into or out of the IMA battery:
    • You can tap off the OEM current sensor signal ... and send a copy of that signal to your own dash mounted display ... a row of leds or a digital display what ever you like.
    • You can use a Current Shunt concept:
      • Adding a pre-designed Current Shunt in line with the battery current flow should be done with care ... this kind of mod would increase the effective resistance of the pack , to make sure it does not cause a problem you will want the smallest resistance shunt you can use to get the level of accuracy you want.
      • Measure the resistance of the aluminum connections used in the OEM design ... the Aluminum piece that goes through the OEM current sensor is a good candidate due to it's length ... and there are already screw connection points on each end of it ... the down side / difficulty is measuring and working with resistances as low as that piece of aluminum will have.
    • Peter's OBDIIC&C device is a OBDII plug in device that can display the IMA current amps or power watts.
• You can install the current hack that Peter used to create a difference between what the car is using and what it thinks it is using ... thus making it use 90amps when it thinks it is using 100amps ... or use 110 Amps when it thinks its using 100 amps ... depending on the direction of the mod ... etc.
• You can install some type of manual control of the IMA system to give control of the amount of AMPs of either Assist or Regen to the driver.
  • You can build your own MIMA L if you are the electronics DIY type
  • You can buy a fully assembled MIMA from Mke D install it yourself or pay someone else to do it for you.
  • You can look into Peter's IMAC&C sytem.

[MetroMPG]

Thanks again for the excellent info, IamIan!

---

FYI your comment about different charging temperatures reminded me to mention this observation when cycling the first 3 sticks (which I did outside of the case):

On the initial charge cycle, different cells in a given stick ended up at noticeably different temperatures, by touch. A few would be noticeably "hot", while a few others were relatively cool, with the balance in between. The pattern of hot, warm & cool cells was different for each of the 3 sticks.

As cycling went on, the cells that were initially "hot" finished at cooler and cooler temps in subsequent cycles, while the "cool" cells' temperature came up. By the 3rd or 4th cycle, all cells in the stick seemed uniformly "warm" to my touch after recharging.

It's not a giant revelation, since we would expect to see this as the dis/charge cycles balanced the cells within each stick. But it was interesting to feel the physical evidence of the cells' initial imbalance.