Hi Hunter,

I'm not so sure that the Imax is the right choice anymore. Like I said in the previoius post, nothing jumped out at me with a blaring, "I'M THE PROBLEM RIGHT HERE!" I went through all of the battery sticks in the pack I pulled from the car. Other that a couple of slightly lower discharges nothing was absolute.

There is only one thing I am sure of... I had recals out the wazoo (that's a technical term). Probably three or four an hour. And they are gone now.

I need to chart the voltage drop over time during a discharge cycle. They have computer connectable charger/cyclers. They're expensive but unless I want to hook these batteries up to a bank of 12volt brake light bulbs and run a stop watch I think it's my only choice.

I am considering purchasing the CBA3 Battery Analyzer. It's about $150 but does what I think I need to do to fully understand the condition of the batteries I pulled from my old pack. If I can determine which batteries are bad and which are still good, I could easily find and replace those bad batteries and have a good replacement pack.

Here's the website:

http://www.westmountainradio.com/pro...code=/cbaLink1

I'd like to know if you continue to get good results with your replacement pack. So far I am very pleased with the results.

Regards!

Ross

 

Ross - what about matching up the 'impedance' of the cells.. I found this post:

"So when trying to decide on which is the better cell , just measure the internal impedance .
MOST RELIABLE MANUFACTURER HAVE NO PROBLEME DIVULGING THE INTERNAL IMPEDANCE OF THEIR CELL ,
The ones that do not have it or won,t specifite it , I would stay away from .
The impedance of battery or cell can be measured using a HP4328A milliohmmeter , this instrument is the standart one used by most battery manufacturer ( check their spec sheet) have recently seem several units sold on E-Bay from $100.00 to $ 800.00.
Have been using one for over 25 years and would not be without it .
It is the first measurement that I make to determine the cell state of health .Regardless of cell chemistries ,volt, amp/hour rating , the impedance is the determining factor how fast you can take the energy out ."

from this thread http://visforvoltage.org/forum/2238-...city-nimh-cell

" low impedance permit higher charge and discharge current Dissipated heat"

So what I'm reading is that you would get rid of cells that have higher impedance since those cells would have trouble with charging and discharging

 

Hi Hunter,

Quite honestly I don't know how I would measure the impedence of a battery. My fluke outputs a small voltage to measure resistance. Don't think I can just connect it to a battery without it going wonkers. Haven't tried it but don't think I care to. :-) It does sound like a good idea. Don't know how reliable it would be on a group of six cells at a time. Maybe fine. Just don't know.

So... between my last post and this one, yep... I bought the CBA III. I expect it by early next week.

All it does is drain the battery through circuitry while it maps the voltage, current and time on the computer. This should give us what we want. I can load a group of cells with up to 150 watts. That's much better than the 1 amp current load the Imax can give us. And we get a picture. I like pictures. :-) A nice graphic of our battery while it is discharged under load. I'll map each stick of cells and then we will have something to truly discuss.

It cost $150.00. ##Razzberry## I ain't made of money! I hope we learn something! Then we can all have a piece of cake.

Regards all!

Ross

 

Ross - congrats on your purchase of the CBA III - it looks like a great tool! I found a resource on how to measure milliohms:

http://www.buchmann.ca/article11-page1.asp

according to that, the impedance/resistance needs to be calculated based on voltage divided by current, which I believe you will have with your CBA tool. (there are other ways to do it with a fixed alternating frequency).

You may be able to recoup some of your costs by helping others or selling off battery packs, or at least keep your HCHII healthy if it starts getting recals.

I didn't have any re-cals today on my second day of the newer battery. I am getting 55+ MPG now over the last 130 miles. The charge level is staying between 6 and 8 bars.

 

Hi Hunter,

That's an interesting article. Still not clear on how you come up with the internal resistance of the battery. But it does sound like the CBA3 will do pretty much what we're talking about graphing current and voltage over time.

I had intended on selling sticks off of the old battery on ebay. See if I could get a few bucks back that way. I've seen others selling HCHI sticks occasionally. Not sure who's buying them... could be a hobbits looking for something more RC related... or maybe someone is rebuilding their HCH pack. Who knows.

But I couldn't in good conscience sell sticks I couldn't be sure were good. The CBA3 should clear that concern up for me. I'll be able to cull out the poor batteries and sell the good ones with a print out of their behavior.

Where did you get your second-hand battery and for how much? I spent $450 for mine.

Ross

 

I got the battery from some recycler in New York for $350 + $50 shipping. He says he kept it charged and it was a 2008 so I bought it without hesitation! It turned out to be a great deal because the dealer would charge $2k, and would keep the old pack

However I've had it sitting in my basement for probably a year because I thought Honda's new software would fix my old battery. I was wrong!

 

I just received my CBAIII battery analyzer. Looks great, feels great... must be great! But it comes with no battery connecting cords or power pole connectors. No Connectors! So it just sits there looking at me shaking it's head saying "dumb, dumb, dumb."

I just ordered ten pairs of power pole connectors off of ebay... my favorite store.

And we wait...

***bother***

 

That is so ridiculous......poor lil charger guy needs some arms to do his work..

Great thread btw, kudos for taking this adventure, has been very informative.

 

Ross - I just did a test with my old (Bad) battery pack and compared it to the new battery pack:

Old battery pack - After charging it to 169 volts, after 4 days of sitting, it drops to 155 volts (14 volt drop!)

New battery pack - After charging it to 169 volts, after 4 days of sitting, it drops to 167 volts (2 volt drop)

this explains why my traditional starter would start the car Monday morning when the car sat over the weekend (with the old battery)

so another test you can try is to charge up the individual sticks, measure and record their voltages, and then let them sit for 3-4 days and re-measure. The good sticks should hold their charge better than the bad ones.

i guess there can be other types of failures but this was the one that I experienced

 

rossfree - if I have it right, the individual cells are "D" cells. Did you consider replacing the OEM cells with higher capacity cells. There are cells available on the market with something like twice the amp-hour capacity.

Internal resistance calculation - take a no load voltage and a voltage under load, take the difference in voltage and divide it by the current used under load. E=I*R or (delta E)/I = R. Select the load current to be high enough to have a good difference in no load to loaded voltages.