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Old 11-12-2006, 12:15 AM   #181
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Quote:
Originally Posted by mha
Make sure that the open side is facing towards the inside of the box. In my case it was mounted the other way around such that the rotating fan was touching the DPDs fan grill. To check without opening look through the fan grill or check that the air is being sucked out of the DPD.

MHA
i can see the fan silver label from the grill

so is it correct?
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Old 11-12-2006, 02:20 AM   #182
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can I use this unit also for 5 cell battery packs without modifying ?
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Old 11-12-2006, 12:06 PM   #183
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Quote:
Originally Posted by yellow15
i can see the fan silver label from the grill

so is it correct?
Correct
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Old 11-12-2006, 12:19 PM   #184
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Quote:
Originally Posted by Dasupacat1
This thing is great. Found out the weakest cells in 2 packs and assemble a practice pack with a closer "match". I was suprised by how bad some of the cells were. Would have never known without this product.
What sucks is I learned I need new batts.
Don't jump to conclusions. If your findings are based on the displayed internal resistance give your cells another chance. The measured internal resistance in hugely influenced by the transfer resistance contact/cell. Take a piece of sand paper and sand all battery connector that have contact to the DPDs contact pins shiny. You will see better values.

If you see huge differences in the capacity readings they might be a hint. But what is huge? I found 500mAh difference within a pack fairly normal even in the best/freshest packs. So I would say huge is >800 mAh. Any other opinions?

MHA
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Old 11-12-2006, 12:43 PM   #185
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You are correct don't take the IR as gospel!

Just for fun i was assembling new packs and decided to throw in my 6 loose cells and of course the PDP don't like 6 loose cells so i laid down 5 battery bars across the appropriate terminals to complete the pack as an "assembled" pack. The IR readings went through the roof! Like 100ohms for the entire pack. I was just looking for some voltages to make sure i had no dead cells but it goes to show how good connections are essential to getting accurate IR readings. So if you have cold solder joints, or simply lots of crap on the ends of you cells(flux,grease dirt what ever) you will get bad ir readings
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Old 11-12-2006, 02:55 PM   #186
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Quote:
Originally Posted by mha
If you see huge differences in the capacity readings they might be a hint. But what is huge? I found 500mAh difference within a pack fairly normal even in the best/freshest packs. So I would say huge is >800 mAh. Any other opinions?
yes i found the same happened to me as well.
I often have a 500mah difference within a pack (and i double check it with a CTX-D2 and got same result), and this happens to my 6 months old 3700 matched packs and also happened to my brand new IB4200 WC matched packs too...
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Old 11-12-2006, 04:02 PM   #187
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i'm not too sure on the accuracy of the DPD...

i have a pack where the DPD says it has a weaker cell (call cell A). has runtime of 3500mah. (the other 5 have 4000mah+)

so i take a cell (call cell B) from anotherpack where on that pack the cell has discharge of 4000mah.

i replace cell A with Cell B.

Charge it up and then discharge. and the now cell B only has discharge of 3500 aswell. wtf?
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Old 11-12-2006, 04:16 PM   #188
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hm.. maybe someone can try swap a "bad" cell and a "good" cell in a pack and see if the DPD gives a consistent result?
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Old 11-12-2006, 04:53 PM   #189
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Ok this is what my 2 Promatch batts were like. I bought these batts "lightly" used off ebay in the spring. Right away I noticed that they would peak well short of the 3700 mah rating . Kinda disappointing. Now I know why.

pack A gp 3700
314
7.40 v
13.4 ohm
2647 mah

405.1 1.24 3416 1.9
373.3 1.24 3151 2.2
398.9 1.23 3364 2.0
393.6 1.23 3320 2.1
314.0 1.23 2657 2.1
434.3 1.21 3659 2.7

pack B gp 3700
310
7.36 v
14.2 ohm
2622 mah

375.0 1.21 3164 2.8
403.5 1.24 3401 2.0
409.1 1.23 3448 2.0
310.0 1.22 2622 2.1
362.6 1.21 3060 2.4
445.1 1.23 3748 2.6

A battery is only as good as it's weeakest cell. So going by this I did some scrambling of the cells. Will cycle and post results of that batt. soon.
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Old 11-12-2006, 05:07 PM   #190
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i think it will be very hard to match based on "runtime" using the DPD. just because the way it discharges.

Since it discharges at 30 amps in series, untill 1 cell reaches 0.9v, then it reverts to discharging independently (equilizing) at about 1amp.

the runtime here will vary depending on how long it is discharging at 30amp.

example, if you discharge a cell at 1amp straight you will be able to extract alot more mah out of it than at 30amp straight, because the voltage will stay above 0.9v alot longer.

anyway Dasupacat, tell us your results once u rematch....
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Old 11-14-2006, 02:26 PM   #191
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I was still a bit annoyed by the rattling noise so took my DPD apart last night trying to get rid of the noise.
After i took it apart (just remove the screws from the button include the 4 hidden one), i found that the cooling fan was just sitting in a slot. There is quite a bit of play between the fan and the slot and no wonder the fan rattle quite a bit when it's turned on. So i just use some servo tape to secure the fan and put everything together and now my DPD is very quiet again!

It's only a 5 mins job and if you know how to rebuild a motor you should be able to fix it yourself.

p.s. I'm not sure if it would void your warranty or not by opening the DPD.
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Old 11-14-2006, 05:12 PM   #192
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Ok this is what I got after shuffling the cells in the 2 pcks.

334
7.36v
13.9 ohms
2824 mah

408.3 1.20 3443 2.7
397.7 1.23 3355 2.0
405.9 1.23 3423 2.2
426.9 1.22 3598 2.1
334.0 1.23 2824 2.0
436.9 1.22 3682 2.4
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Old 11-15-2006, 03:46 AM   #193
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Default DPD and 5 cells

As you know, last week EFRA changed the number of the cells from 6 to 5. I'd like to buy the new black DPD discharger. Can you tell me please if the DPD supports 5 cells packs for the internal discharging tray?

thanks in advance
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Old 11-15-2006, 03:52 AM   #194
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Quote:
Originally Posted by Dasupacat1
Ok this is what I got after shuffling the cells in the 2 pcks.

334
7.36v
13.9 ohms
2824 mah

408.3 1.20 3443 2.7
397.7 1.23 3355 2.0
405.9 1.23 3423 2.2
426.9 1.22 3598 2.1
334.0 1.23 2824 2.0
436.9 1.22 3682 2.4
so that 2824 cell, which one was that in the previos post?
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Old 11-15-2006, 04:29 AM   #195
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cell 5 , pack a if I remember correct
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