BC-6 funny balancing behavior

[yellowbillycat]

So I've had my BC-6 since last fall. I've been using it to balance charge FlightPower 1600 3S and recently FlightPower 2500 3S packs. Up until yesterday it has been working flawlessly. It always balance charges an 80% discharged pack in under an hour, usually 50-55 minutes.

Starting yesterday it has started timing out (set for 60 minutes) on the same 80% discharged 2500 packs. It seems to be endlessly trying to balance the cells. The charge current is bouncing back and forth between 0 and 0.1A. That alone seems strange as I thought the charger declared full when the current during the CV phase dropped below 0.1C.

The 2500 packs that is taking longer to charge (I'm still running a balance charge to see how long it actually takes to fill an 80% discharged pack) have only 16 flights on each. For the first 14 flights they charged normally, starting at flight 15 the balance seems to take much longer.

I also received brand spankin' new flightpower 2500 3s packs yesterday, and they displayed the same issue (>60 minute balance) right out of the package. They came charged to about 11.5V or so.

So is this a real issue? An 8 minute flight that used 2000mAh out of 2500 used to balance in 50-55 minutes, now it takes 65-70. Whatup?

Erik

[yellowbillycat]

I just finished charging a 2500 3s pack without a timeout. 70 minutes. So balancing both the same packs, as well as new 2500 3s packs, has gone from 55 minutes to 70 minutes seemingly overnight.

Erik

[RC Accessory]

More than likely the EAC129 connection board needs to be replaced. The internal resistance due to the board is higher now due to wear. TP taps are known to be difficult to get out of the sockets due to the tap.

It is recommended by many that the tab on the tap itself be removed. This will make insertion and extraction of the balance tap easier on the socket.

Bantam has modified the EAC129 board as well. The newer boards, Bantam has made the board larger and the sockets are separated more to allow your fingers to better grip the tap. The bottom of the board is now also covered in plastic to better protect the board traces.

I recommend that you replace the EAC129 connection board.

[yellowbillycat]

I'll give that a try, thanks for the help!

Erik

[summerwind]

More than likely the EAC129 connection board needs to be replaced. The internal resistance due to the board is higher now due to wear. TP taps are known to be difficult to get out of the sockets due to the tap.

It is recommended by many that the tab on the tap itself be removed. This will maker insertion and extraction of the balance tap easier on the socket.

Bantam has modified the EAC129 board as well. The newer boards, Bantam has made the board larger and the sockets are separated more to allow your fingers to better grip the tap. The bottom of the board is now also covered in plastic to better protect the board traces.

I recommend that you replace the EAC129 connection board.

oh sure, the one i just bought had a piece of foam rubber on the back........where's the plastic?:cheers

[summerwind]

on a more serious note, is the a cable that goes from the charger to a 4 pin female so that the FP 3S batteries i use can just be plugged in so as to skip the adapter board?

[RC Accessory]

on a more serious note, is the a cable that goes from the charger to a 4 pin female so that the FP 3S batteries i use can just be plugged in so as to skip the adapter board?

No, but you can easily make one yourself.

You would need of 1 each of these parts:

http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=136
This is the charger balancer end.

http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=245
This is the female end for the battery.

From the balance port side:

Pins 1 & 2 go to the negative pin on the female connector.
Pin 3 goes to next pin on the female connector.
Pin 4 goes to the 3rd wire on the female connector
Pin 5 is the positive lead on the female connector.

You can determine the negative lead on the female by matching to the battery. Never assume that a black wire is negative and a red wire is positive, only bad things with batteries happen when you assume. Also, this connection wire will work on your Two Meter as well.

Anytime I make such leads, I test on the Two Meter first before the charger.

[phillipda]

I'm having the same problem, but mine times out after 150 minutes with my Flightpower pack, which has done Apx 60 tame flights. Got a new Outrage pack and it balanced in 50 minutes for the first few flights now it's starting to take almost 70 minutes to balance.

Would it be possible to purchase a separate balancer to plug into the BC6 charger?

Because of the time it takes to balance charge, for the last week I been starting to use the Fast Charge feature on the BC6, after viewing the reviews that Finless Bob has recently posted, He mentioned that the fast charge mode still balances your packs. It now only take me 35 minutes to charge the packs using fast charge.

One thing I have noticed recently since using the fast charge feature and that is, When the charging has finished the readings on the BC6 for the individual volts of each cell on my 3 cell packs are different. The first one is always shown lower that the next two. Today I noticed my flight power pack after a Fast charge, when the charging process finished it was showing 4.14v, 4.17v, and 4.2v. on the screen, and yet during the charge process the voltages are shown as even. I monitored the voltages today on the pack as it was fast charging and the voltages shown very even, it's only when the charging finished that the voltages shown which I mentioned. Is this normal?

[RC Accessory]

I'm having the same problem, but mine times out after 150 minutes with my Flightpower pack, which has done Apx 60 tame flights. Got a new Outrage pack and it balanced in 50 minutes for the first few flights now it's starting to take almost 70 minutes to balance.

You need to check to see that you are putting the same mah back into the pack. The additional time is more than likely becuase you flew the pack longer or discharged the pack further.

Would it be possible to purchase a separate balancer to plug into the BC6 charger?

Sure, any external balancer would work.


One thing I have noticed recently since using the fast charge feature and that is, When the charging has finished the readings on the BC6 for the individual volts of each cell on my 3 cell packs are different. The first one is always shown lower that the next two. Today I noticed my flight power pack after a Fast charge, when the charging process finished it was showing 4.14v, 4.17v, and 4.2v. on the screen, and yet during the charge process the voltages are shown as even. I monitored the voltages today on the pack as it was fast charging and the voltages shown very even, it's only when the charging finished that the voltages shown which I mentioned. Is this normal?

The battery is degrading. The BC-6 will try to balance the pack but it does know when the cells just can't take anymore.

[phillipda]

Thanks for the reply Evan.

I keep a log book of all my flights and monitor all charges including how much I put into the pack each charge and how long I fly for.

On average every flight after a 6 minute hover, (i'm a beginner) I put back in 1250 into my Flightpower 2170 EVO25 3 cell pack and that's using fast charge, I do a full balance charge every 5 or 6 flights and it puts back in 1510 usually taking about 130 minutes to complete.

I started using the Fast charge feature on my BC6 a week ago. It only takes 35 minutes.

[phillipda]

Just gone over my logbook for the Flightpower pack,

When I first purchased the pack it took about 50 minutes to complete a balance charge, putting in about 1300 into the pack. After a few charges the balance charge started to take longer to complete. It now takes over 130 minutes to complete a balance charge.

Fast charge option works great for me, Hopefully it is not degrading my pack, I been told it would actually help to improve the life of the pack by using fast charge, Is this true?

In regards with the New Outrage pack. so far it's only done 11 flights of 6 minutes hover putting back in between 1250 to 1300 after a balance charge. The first 3 or 4 charges took 50 minutes the finnish the balance charge, now after 11 flights it's taking 70 minutes. I am going to start using fast charge on this pack as well.

[summerwind]

No, but you can easily make one yourself.

You would need of 1 each of these parts:

http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=136
This is the charger balancer end.

http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=245
This is the female end for the battery.

From the balance port side:

Pins 1 & 2 go to the negative pin on the female connector.
Pin 3 goes to next pin on the female connector.
Pin 4 goes to the 3rd wire on the female connector
Pin 5 is the positive lead on the female connector.

You can determine the negative lead on the female by matching to the battery. Never assume that a black wire is negative and a red wire is positive, only bad things with batteries happen when you assume. Also, this connection wire will work on your Two Meter as well.

Anytime I make such leads, I test on the Two Meter first before the charger.

got around to making up a couple of these today.......worked great, and much more compact.

[cbdane]

Known problem with the Bantam chargers, I'm afraid. My balance connectors have no traces to degrade. Just high quality gold-plated connectors. Ditch the "balance" mode and keep flying. More details here:

http://www.helifreak.com/showthread.php?t=70086

[RC Accessory]

Not a known issue. Limited in scope and each time traced back to the boards. While that does not explain your situation, it is not a "known" issue.

[cbdane]

Not a known issue. Limited in scope and each time traced back to the boards. While that does not explain your situation, it is not a "known" issue.

Let's see; I think you are confusing "issue" with "problem." "Problem" would be something that definitely needs to be fixed; an error; a malfunction. "Issue" is simply a topic of discussion, confusion, or even misunderstanding that may or may not constitute a real problem. Tell you what, search for Bantam balance charging topics on this forum (and others) and decide whether it might qualify as an "issue." Even if it is related to the balance boards (which it isn't in my case), it is still an "issue" with what is otherwise a fine charger.

[yellowbillycat]

Evan,

I purchased new, plastic backed interface boards as you suggested and I am continuing to see the same issue with the charger. I have tried this with 2 new boards.

At this point the charger takes between 120 and 150 minutes to decide it is done with a balance charge. The funny thing is that when I place [edit: a full, bc-6 charged] pack on a separate, dedicated balancer, or a different brand balancing charger (so far I have tried hyperion and electrifly) they all complain about the balance state of the cells.

Additionally a DVM indicates that the max delta between any two cells is always >= 0.011 V.

All packs always end up with cell #3 at the highest voltage.
If I stop the charge in the CV portion when the charge current is at 0.1A, cell #2 will be the lowest voltage. Always.
If I allow the charger to run 150 minutes to completion , cell #1 will be the lowest voltage.

These same packs balance charge on a hyperion charger in 60-65 minutes. I alwys fly 7 minutes putting back 1600 mAh +/- 7%. Tomorrow I will take individual cell measurements after a hyperion charge just to make sure it isn't balancing "sloppily".
The packs are all FlightPower evo lite 11.1V 20C 2500 mAh.

From the charging behavior it LOOKS (this is an attempt at an educated guess, not fact, mind you) as if the bc-6 is not measuring individual cell voltages correctly and is actually forcing the cells to an unbalanced state while in the CV portion of the charge.

Any thoughts?

Thanks,

Erik

[RC Accessory]

Evan,

I purchased new, plastic backed interface boards as you suggested and I am continuing to see the same issue with the charger. I have tried this with 2 new boards.

At this point the charger takes between 120 and 150 minutes to decide it is done with a balance charge. The funny thing is that when I place the pack on a separate, dedicated balancer, or a different brand balancing charger (so far I have tried hyperion and electrifly) they all complain about the balance state of the cells.

Additionally a DVM indicates that the max delta between any two cells is always >= 0.011 V.

All packs always end up with cell #3 at the highest voltage.
If I stop the charge in the CV portion when the charge current is at 0.1A, cell #2 will be the lowest voltage. Always.
If I allow the charger to run 150 minutes to completion , cell #1 will be the lowest voltage.

These same packs balance charge on a hyperion charger in 60-65 minutes. I alwys fly 7 minutes putting back 1600 mAh +/- 7%. Tomorrow I will take individual cell measurements after a hyperion charge just to make sure it isn't balancing "sloppily".
The packs are all FlightPower evo lite 11.1V 20C 2500 mAh.

From the charging behavior it LOOKS (this is an attempt at an educated guess, not fact, mind you) as if the bc-6 is not measuring individual cell voltages correctly and is actually forcing the cells to an unbalanced state while in the CV portion of the charge.

Any thoughts?

Thanks,

Erik

In that case I would recommend that your charger get checekd out by Bantam at the factory. Contact your dealer about sending the unit back to be checked out.

[yellowbillycat]

Evan,

I have contacted Bantam to see how to go forward. I will also contact my retailer.

Thanks for putting the time in to answer my questions.

Just for completeness, after flying yesterday (same pack usage) I charged on a Hyperion.
The charge took 48 minutes on average and I ended up with cell balanced to within 0.002 to 0.005 volts. So my packs are OK.

So we'll see what Bantam has to say.

Erik

[yellowbillycat]

Evan,

I e-mailed Bantam directly a week ago and haven't heard back. I contacted my dealer this evening, so I'll see what that yields.

Just a quick question: If my dealer cannot return the unit to Bantam for repair, can RcAccessory send it back and if so, what would that cost?

Thanks,

Erik

[RC Accessory]

Evan,

I e-mailed Bantam directly a week ago and haven't heard back. I contacted my dealer this evening, so I'll see what that yields.

Just a quick question: If my dealer cannot return the unit to Bantam for repair, can RcAccessory send it back and if so, what would that cost?

Thanks,

Erik

PM sent.

[yellowbillycat]

I have heard back from both Bantam and my dealer. The BC-6 is going back to the mothership to be repaired or replaced (depending on the findings) under warranty.

It's always interesting to see how companies handle problems, it tells you more about them than when everything is working fine.

So far Bantam, RC Accessory, and Helidirect have proven to be responsive and helpful in getting this resolved.

Erik

[yellowbillycat]

Just to close out this thread....

I returned the charger to the retailer who in turn sent it back to Bantam. It was determined to be faulty and I received a new unit. Total turnaround time was 7 days.

I've been using the unit for a couple of weeks now and it behaves as expected. Charge times on 2500 3s packs discharged 70-80% are under 1 hour. Cell balance is <= 10mV.

Thanks to Bantam, HeliDirect, and RC Accessory for their roles in resolving this.

Erik