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IB3800 with 507 seconds at 30A seems fishy, anyone else seen this before?

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Old 03-23-2006, 07:36 PM
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IB3800 with 507 seconds at 30A seems fishy, anyone else seen this before?

Hello,

I was given a battery pack as a sample. It came from a matching company I will not name. The numbers seem really fishy to me, so I cycled a few to check them out. The labels on them are as follows:

The cells are IB3800 with the date code AACEU
507 seconds
1.216-1.223 Average Voltage
5.0A Charge
30A Discharge
13-15 IR
5000 runout
0.9 Cutoff

Should I be able to match these results with my Turbo 35 GFX and a cell holder?

I was able to get 446 seconds with an average voltage of 1.164 an an RIR of 18. It peaked at 1.522 V and was 129.9 degrees.

I am thinking these cells have labels intended for a 4200, but can't confirm that yet. My main question is should I be able to repeat the numbers or close to if I am using the same charge/discharge rates?
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Old 03-23-2006, 07:41 PM
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When you cycled them did you use both the big and small leads on your gfx? If you dont the numbers dont come up right. I have never seen an IB3800 with less than 1.18 voltage so im guess this is what you did.
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Old 03-23-2006, 07:52 PM
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Yeah, I have both leads connected. The larger one to the heavier terminal and the smaller to the lighter of the 2 terminals.
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Old 03-23-2006, 07:53 PM
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those numbers can be gotten if matched and zapped right, 500 secs at 30 amps can be gotten on 3800s as high as 512 even so ........ please note im not stating those numbers on that pack is true or false all im stating is that 1.21+ volts and 500+ runtime can be gotten at 30amp discharge rates.....
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Old 03-23-2006, 07:56 PM
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What do you mean the larger one to the heavier terminal? You should have both red leads to the postitive bar on your pack and both blacks to the negative bar on the pack. The 2 reds should not be touching and same with the blacks.
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Old 03-23-2006, 07:57 PM
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Originally Posted by gmintimidator
Yeah, I have both leads connected. The larger one to the heavier terminal and the smaller to the lighter of the 2 terminals.
Check this out. Use a DVOM and when you are discharging the cells. Measure the voltage right at your connection to the battery. Check the voltage on your meter and the voltage on the charger display. If they are the same you have good connections. If you have a different reading. Your charger is bad.

At 30 amp those numbers are not unheard of.
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Old 03-23-2006, 08:01 PM
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did you charge them and then discharge them right after they got done charging
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Old 03-23-2006, 08:09 PM
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I can't verify that for sure tonight, I lent out my Fluke meter to a friend the other day.

Hopefully the charger is ok, I've had it ordered in and I've only had it for 2 months.

I charged up the battery, let it sit for 2 minutes so I can get a fan on it and then started to discharge it
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Old 03-23-2006, 08:25 PM
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Here is a pic of a connection
Attached Thumbnails IB3800 with 507 seconds at 30A seems fishy, anyone else seen this before?-img_0958.jpg  
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Old 03-23-2006, 08:44 PM
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I just finished cycling a cell I ran about 5 hours ago. I discharged it to 0.9V both times before I started the cycle.

4280 vs 4638 mahr of charge
1.529 vs 1.522 peak voltage
18 RIR both times
447 vs 446 seconds on the discharge
1.172 vs 1.164 V on the Ave voltage
1.181 vs 1.174 V on the Ave 1V
3725 vs 3716 mahr output
4365 mwhr vs 4325 mwhr

Some numbers have improved. Would this have anything to do with the pack having sat for a week or two or longer since it was matched?
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Old 03-23-2006, 08:46 PM
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I have a GFX and a 4/35 matcher. The numbers are never the same between the two.

I never seem to get numbers as good as the original labels either. You are best off just comparing your packs to one another. Find a company or two, or three that you trust and go from there. You can't really compare numbers from company to company either. It's not worth trying.

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Old 03-23-2006, 08:51 PM
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Yankey

If you're using the same equipment as there using, shouldn't you be able to get those same numbers? I can understand some variance say plus minus 2%, but not not short 60 seconds....

How close are your numbers to the label?

What are you using for the pdv on your GFX?

I assume the pic I posted of the connection is a proper connection?

I was hoping to tell if this company is trustworthy by seeing if this pack was as good as it looks, but if I can't check it, how do you honestly know??
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Old 03-23-2006, 08:51 PM
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I just read some more of your posts. A typical matcher will peak, possibly repeak, and then immediately discharge. Letting the battery sit for two minutes will make the numbers look worse. Also, if you are cooling with a fan, that is another variable. Every little thing that you do differently than the original matcher will change the numbers, sometimes significantly.

Also, with the CE cell tray you need to make sure the contacts are very clean. CE recommends Pacer "rail zip".

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Old 03-23-2006, 08:59 PM
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I will look into that rail zip, with any luck I can steal some from my dad's train layout!

I will try some more testing tomorrow and try a repeak with an immediate discharge. I really don't like the idea of hitting a cell at 30A without a fan. Won't the heat kill the cell? I can't see a matcher letting the temperature get really hot like that and risk killing the cell. I could verywell be wrong though.

I appreciate everyone's input so far, much appreciated.
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Old 03-23-2006, 09:02 PM
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The GFX is not at all the same equipment. You need a turbomatcher 4/35 (most likely) to get even close. I would say a 40 second difference is not uncommon from GFX to turbomatcher numbers.

Also, even if you have the 4/35, you need to be at the same room temperature as the pack was originally matched, that makes a difference. Also, the numbers on the matcher change if the matcher is cold versus warmed up. etc. etc. etc. There are tons of factors.

As far as comparing packs, try cycling some of your better packs and compare them to the new pack. Company A's 500 may be company B's 480. The best advice I can give is just do what you are doing exactly the same to each pack and then compare amongst your own cells. You will also get to know approximately how various companies numbers compare to your machine and to eachother.

For a single cell 3800, I believe the standard is .01 for peak and repeak.
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