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Old Apr 04, 2008, 04:58 AM
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Quote:
Originally Posted by junsi
We indeed add a Sil-Pad to the bottom of the 1010B balance expansion board (see picture),which can protect the user from loss!
That should work just fine. Was impossible to tell from earlier pictures posted

Eagerly waiting for those voltage measurements later today

T
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Old Apr 04, 2008, 06:17 AM
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Note that it is a public holiday in China and HK today so I doubt we will hear anything from Junsi until Monday his time.
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Old Apr 04, 2008, 06:20 AM
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Yes, you are right - hopefully monday then

@junsi:
Is there some kind of short protection on the balancer expansion board, or in the in-charger circuit? I'm thinking what happens if the user connects the 2x3S lipo packs to the charger with a normal series wire harness, but mistakenly switches the plugs on the balancer board? That is balancer plug for pack #1 goes in balancer board socket #2, and #2 in socket #1...

T
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Old Apr 04, 2008, 06:43 AM
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I think you will find that will let the magic smoke out of the battery and possibly melt tracks on the adapter board but I believe the charger has short ciruit protection on the output so will not be harmed.

That is one of the risks of providing a 2-way or 3-way adapter. There is no reasonable way to protect against the user plugging in the balance leads incorrectly.
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Old Apr 04, 2008, 07:20 AM
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One could reduce the problem by not having a connection between pin 4, socket 1 and pin 1 socket 2 at the balancer expansion board since this will be taken care of by the (correct) serial connection of the packs. The problem is that voltage drop, caused by charging current, would affect the balancing of the pack.

Fred
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Old Apr 04, 2008, 09:06 AM
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@kgfly:
I know about the smoke part, I was just trying to confirm whether the charger itself would survive such a mishap or not

T
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Old Apr 04, 2008, 09:20 AM
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Page 17 of the manual shows that the possible error messages include

"Short Error" = "A short-circuit at output. Please check the charging leads."
"Reverse Polarity" = "The output is connected to a battery with incorrect polarity."

I think this shows that the charger should be OK.
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Old Apr 04, 2008, 12:16 PM
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Even the chargers reported broken by such incidents have error messages relating to a output short. So this alone doesn't seem to mean that the charger will survive a mixed up blanacer wiring...

There's no way to be 100% foolproof when it comes to electrical connections, but some "countermeasures" help limit the damage.

T
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Old Apr 05, 2008, 08:13 AM
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Quote:
i agree with you, but in the balance charging mode, the voltage of cells would be detected correctly by balance port. the voltage drop can be ignored since the current passing the balance port is very small.
Hi Junsi,

I still have a question on how the voltace of the cells/pack is checked in the different charging modes.
You write, that in the balance charging mode, only the voltage of the balancing contacts is used to control the charging current.
So, if I used a cable with a fairly high resistance, the charging current would still not be reduced, until the balancing contacts detect the voltage of 4.2V/cell. It would not matter if the voltage is a little higher at the normal charging cable. Is this correct?

When being in normal charging mode, with the balancer cable not connected, of course only the voltage of the normal charging cable can be taken into account.

But what if the balancer cable is conncted in this charging mode?
I understand thet the charge is terminated when one cell shows more than 4.25V.
But which voltage is used to control the charge current? Is it the voltage of the charging cable, or the voltage of the balancing cable?

Cheers,

Julez
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Old Apr 05, 2008, 10:28 PM
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Quote:
Is there some kind of short protection on the balancer expansion board, or in the in-charger circuit? I'm thinking what happens if the user connects the 2x3S lipo packs to the charger with a normal series wire harness, but mistakenly switches the plugs on the balancer board? That is balancer plug for pack #1 goes in balancer board socket #2, and #2 in socket #1...
Balancer expansion board has no short protection. But the short canít damage iCharger.
Normal, the OUTPUT port is not connected directly to the balance port in iCharger. There is high impedance between them, So, Any mistake on balance port donít result in short in iCharger.

Quote:
One could reduce the problem by not having a connection between pin 4, socket 1 and pin 1 socket 2 at the balancer expansion board since this will be taken care of by the (correct) serial connection of the packs. The problem is that voltage drop, caused by charging current, would affect the balancing of the pack.
IMO, The Smart balancer expansion board will be come true, it has more FETs to switch the sockets on the exp. board. The FETs is controlled by MCU.

Quote:
I know about the smoke part, I was just trying to confirm whether the charger itself would survive such a mishap or not
Yah, iCharger will survive.
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Old Apr 05, 2008, 10:42 PM
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Quote:
Originally Posted by Julez
Hi Junsi,

I still have a question on how the voltace of the cells/pack is checked in the different charging modes.
You write, that in the balance charging mode, only the voltage of the balancing contacts is used to control the charging current.
So, if I used a cable with a fairly high resistance, the charging current would still not be reduced, until the balancing contacts detect the voltage of 4.2V/cell. It would not matter if the voltage is a little higher at the normal charging cable. Is this correct?

When being in normal charging mode, with the balancer cable not connected, of course only the voltage of the normal charging cable can be taken into account.

But what if the balancer cable is conncted in this charging mode?
I understand thet the charge is terminated when one cell shows more than 4.25V.
But which voltage is used to control the charge current? Is it the voltage of the charging cable, or the voltage of the balancing cable?
Yes, you are right, we have bring it into consideration. In the balance charging mode, there are two limiting conditions: Vcell < 4.2V, and Vout<(count*4.2+0.1V), you can see 0.1V, it can solve the problem you mention to.

In the normal charging mode, there is only one limiting condition: Vout<count*4.2.
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Old Apr 06, 2008, 12:57 AM
PGR
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Australia, Germany, Norway .... Just wanted you to know, junsi, that there's plenty of interest here in the USA as well. After reading this thread, it's apparent to me that your company is eager to give the customer what we want instead of what an executive think-tank feels we need and I applaud this philosophy.

On second thought, the philosophy deserves a standing ovation!

Pete
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Old Apr 06, 2008, 08:25 AM
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Quote:
In the balance charging mode, there are two limiting conditions: Vcell < 4.2V, and Vout<(count*4.2+0.1V), you can see 0.1V, it can solve the problem you mention to.
Thanks for your answer!

My original idea was more like Vout<(count*4.2+(R*I)), with R being settable by the user, and I being detected by the charger, but your solution seems to be ok, too.

Cheers,

Julez
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Old Apr 06, 2008, 09:11 AM
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Quote:
Originally Posted by junsi
Balancer expansion board has no short protection. But the short canít damage iCharger. ...
This is looking more promising with every post Junsi.

T
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Old Apr 06, 2008, 10:33 AM
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Junsi, here's something new to ponder:

The first detectable sign that something is going wrong during a charge cycle is typically the puffing or swelling of a pack. If you develop a reliable way to detect the earliest signs of puffing and use that signal to terminate the charging cycle and sound an alarm, you'll be well on your way to developing the safest charging system on the market.

Pete
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