Ross, Hunter;

Is it possible that there is nothing wrong with our batteries other than the cells need to be fully charged in order to balance them? The current software only charges to 80% which is inadequate and will NEVER balance the cells. If all the cells could be charged to 100%, would that possibly cure some/most of our battery problems?

If your answer is "yes", then I assume that Honda knows this also but to correct the problem would be cost prohibitive for them (**** us!).

 

Jatra - Yes its very much possible that our batteries can be put back to use after a 'reconditioning', according to first gen Honda Insight owners that have done this.

I have already 'topped off' my old battery but would have to swap it out with the new one I have to prove out. I will probably do it in the next few weeks to see that fixed it. Should be interesting.. I would then have two good batteries

 

hunter44102:
Do you find the swap of the packs much of a effort? Can you handle the pack yourself? H

 

The pack is like 40-50lbs so its not super light, but manageable. i have carried them up and down my basement stairs a few times for charging.

getting to the battery just takes time - I have a baby child seat in the back so i have to remove that and everything else to get to the battery, along with explaining to my wife what I'm doing. I wish they could have fit it somewhere under the hood or in the trunk so it wouldn't require messing with the interior.

 

ok, i've been working on trying to restore my old battery (without opening it, using only grid charger). here is the entire progress so far:

1) I noticed the old battery (that has re-cals) had a faster self discharge than the newer battery with no re-cals.
2) did a 'grid' charge on the old battery with 350mA and it went up to 176V and stopped going up.
3) Battery settled to 167V after 2 days.
4) did a second 'grid' charge on the old battery with 400mA and it went up to 181V and stopped going up. this may be a good sign, like i've restored its upper limit, or maybe the higher current was able to overcome a weaker cell?

Now I need to let it settle and see if the self-discharge slows down.. if that's the case I will put it in the HCHII and see if re-cals are gone on this battery.

 

Getting interesting! H

 

Boy... I want to be optimistic here but I just don't know. I think we might be oversimplifying the problems. There are a lot of good sites out there talking battery chemistries and how over time they degrade or discharge quicker. They talk about how the crystals become larger, reducing surface area and lowering power output. It's hard to get a handle on what it would take to bust those crystals up so that you get a better charge.

It seems I ran across a website talking about smacking a high current 1-2 second pulse on a pack of batteries (for a drill or something like that). It would supposedly break down the memory build-up in the cells. I do not remember if it was NICAD or NIMH chemistry.

Anyway, keep us posted on what you learn. I'm very curious to know your results.

Ross

 

Ross - I guess we'll find out soon enough. I was originally convinced I had a bad pack, and that's why I bought a good used one just like you did. After reading this first post from Robert Smalls, I changed my tune. I will find out soon enough.

http://ecomodder.com/forum/showthrea...vic-13610.html

My understanding is that there are two possible issues 1) Cell imbalance, or 2) True degradation of capacity. Using these batteries from 20 to 80% was supposed to make them last 30+ years (unless they were abused). The degradation issue supposedly causes an IMA light. The cell imbalance just causes tons of re-cals which takes out 10MPG's of mileage with all the re-gens, hidden regens, and re-cals - not to mention the loss of power (since it won't allow assist when re-cal).

I can't find anything on the web about why one NIMH battery pack would discharge faster than another with no load connected. I have a theory but I'll save it until I can prove this out.

The large spike of current/voltage you read about could be for the 'cell reversal' issue. If NIMH batteries/pack sit too long, one or some cells will reverse and become a Load that dissipates the others. A large voltage spike will take the cell out of reversal so it can be charged with a normal charger.

I don't believe my pack has any reversed cells or it would have gone up in smoke by now with the high voltage I brought it up to!

 

The old battery still has a 'self-discharge' issue even after 2 full grid charges.

I will now go through the process of discharging it and re-charging fast and see if I can recover some capacity and fix the discharge issue.

Worst case I have some bad cells I'll have to find and replace.

Attached is a photo of the discharge using two 60W 120v light bulbs in series. I may need to use 100W to drain it faster

 

Hi Hunter,

Two 60's in series would probably draw about an amp of current from a pack. Does that sound right? These packs can give up a lot more current than that. But i don't know just how much. I imagine a 20amp draw is not unreasonable. That's a lot of light bulbs. :-) Sounds like you might want to get an old ceramic heater element and use something like that. But you want to measure those amps so you know the load you are placing on it.

You da man!

Ross