Help - A123 Astro blinky balancer issue!  
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Help - A123 Astro blinky balancer issue! - 1/6/2008 6:06:50 PM   
747



Posts: 252
Joined: 9/14/2003
From: Downingtown, PA, USA
Status: offline 		Hi

I made a pack of 5 cell A123. All cells were about 3.3v except one (cell #2) which is 3.15v. I connected the Astro A123 blinky for the 1st time today and when I connect for the 1st 3 secs all 5 LEDs light up, after which 4 LEDs start blinking and the one for cell#2 is OFF, why? If it is really "balancing" shouldn't they all be blinking? I am certainly in the "balancing region" of 3 to 3.6v right?

After about 10 mins of "balancing" , I checked again. The balancer was warm to touch, the voltages were:
3.14v for cell#2 and the rest were 3.29v each. Obviously the "balance" didnt happen, just that the LEDs took some power thats all ...right?

I am new to EP , so how long does the "balancing" take place, should I wait and balance for more time ?
Or is something wrong with connections . This is how I did:- First Black goes to most negative point which is of cell #1, next wire goes to positive of cell #1, next wire to positive of cell #2, and so on up to positive of cell #5.

I am using a 10 pin connector with battery connection with only 6 wires.
Is there a reason why the first 2 wires are both black? or does it not matter? Here it is:
http://www.allelectronics.com/cgi-bin/item/CON-2410/189/10-PIN_CONNECTOR_W__HEADER,_.1%22#34;_SPACING_.html

Pls advice what is wrong! See attached (yes I like pics for some reason )!

Thanks
--747.

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< Message edited by 747 -- 1/6/2008 6:16:45 PM >

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RE: Help - A123 Astro blinky balancer issue! - 1/6/2008 6:38:12 PM   
ct420


 

Posts: 1177
Joined: 3/26/2006
From: mansfield, TX, USA
Status: offline 		It sounds to me like you have everything wired OK. However, it seems that 1 cell has a much lower charge state than all the others. If so, it is going to take the blinky a LONG time to bleed the other cells down to match the low one.

Probably the simplest solution is to just let the blinky run until it finishes balancing. Might take a whole day and/or night to do it...

Or, you could charge the low cell up to around the same level as all the others, then the balance wouldn't take as long...

Good luck!

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RE: Help - A123 Astro blinky balancer issue! - 1/6/2008 7:17:12 PM   
747



Posts: 252
Joined: 9/14/2003
From: Downingtown, PA, USA
Status: offline
quote:

ORIGINAL: ct420

It sounds to me like you have everything wired OK. However, it seems that 1 cell has a much lower charge state than all the others. If so, it is going to take the blinky a LONG time to bleed the other cells down to match the low one.

Probably the simplest solution is to just let the blinky run until it finishes balancing. Might take a whole day and/or night to do it...

Or, you could charge the low cell up to around the same level as all the others, then the balance wouldn't take as long...

Good luck!


Hi! So it IS ok to do the balance for a long time...wow...Blinky was warming up in 10-15 mins and I removed it! Is it normal for blinky to get warm to touch?

Right now the 4 cells are at 3.29v , 1 cell is at 3.14v. After balance , roughly what would be the voltage in each cell (since the LEDs also use up power to flash). Would it be say like 3.10 v for all 5 cells?

I am not sure if the concept of a balancer is to make all cells match the lowest voltage one OR decrease the higher ones and at the same time increase the low voltage one to "arrive" at a middle point? I know it sounds crazy but I wanna know if the blinky can only "bleed" voltages and not increase them!! ...thanks





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RE: Help - A123 Astro blinky balancer issue! - 1/6/2008 9:02:36 PM   
ct420


 

Posts: 1177
Joined: 3/26/2006
From: mansfield, TX, USA
Status: offline 		There are different types of balancers that use different concepts. I don't have a blinky myself, but I do have something similar.

I am pretty sure the Blinky is a 'stand-alone' balancer only. Meaning, you do not connect it between the charger and the battery so it can limit the charge to any particular cell.

With the blinky, just connect it to the battery before charging. It should reduce the voltage over every cell in the pack to match the cell with the lowest voltage. In your case, all cells should end up at around 3.14v. Once it's finished, remove it and connect the pack to your charger and charge it up.

Yes, it should be OK to leave it connected for days without any problem. It is OK if it gets a little warm, but should never get 'Hot' feeling at all. Again, I don't have a Blinky, so I can't say for sure how warm it will get, but I know my LBA6 does get a little warm when balancing a badly unbalanced pack. Probably not more than 100F though, if that....

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RE: Help - A123 Astro blinky balancer issue! - 1/6/2008 11:05:21 PM   
747



Posts: 252
Joined: 9/14/2003
From: Downingtown, PA, USA
Status: offline 		But my concern is that the lowest voltage cell and the other 4 cells are slowly coming lower (by.01 v) . SO I hope over time only the 4 high voltage ones discharge at a faster rate to catch up with the Low voltage one (which also bleeds a bit- is this normal?)

I guess my question is , does it happen to you guys too, that the Lowest voltage cell ALSO bleeds a bit

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RE: Help - A123 Astro blinky balancer issue! - 1/7/2008 12:38:19 AM   
everydayflyer



Posts: 889
Joined: 8/21/2005
From: Buchanan, GA, USA
Status: offline 		Blinky type(bleeding) balancers work by discharging all of the higher voltage cells down to match the lowest voltage cell.


First off you should charge the pack them balance it. Inbalance will be at its worst 99% of the tiime when the pack is not fully charged.

Second balance of A123 cells is not criticasl like LiPolys.

Third A123 cells will settle down and stay more in balance after they have been charged and discharged a few times.


It is always faster to charge the low cell than to discharge the high cells with a balancer.
The Blinky is extremely slow to correct much of an inbalance. It only discharges approx. 120 mAh.

Charles

< Message edited by everydayflyer -- 1/7/2008 12:41:39 AM >

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RE: Help - A123 Astro blinky balancer issue! - 1/7/2008 1:41:06 AM   
747



Posts: 252
Joined: 9/14/2003
From: Downingtown, PA, USA
Status: offline
Great info. I use the "Astroflight 109 A123 Cell Charger " , 4th in link below:

http://www.battlepack.com/chargers.asp

I dont have a wall adapter for it. It needs a 12v dc input(has aligator plugs). I plan to charge from the car battery once I am in the field. Since I cant fly now how can I charge it?

1.Pls suggest a wall adapter (correct V , Amps etc)
2.Pls suggest if I can buy a rechargeable battery that people charge at home and use in field to charge the A123s.

Thanks

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RE: Help - A123 Astro blinky balancer issue! - 1/7/2008 2:27:31 AM   
everydayflyer



Posts: 889
Joined: 8/21/2005
From: Buchanan, GA, USA
Status: offline 		First off 2300 mAh A123 cells take on average .66Ah per cell to charge. If you have a 10cell pack that is 6.6Ah per charge.

You could use one of the Automative Jump Starters such is sold by HomeDepot,PEP Boys, Auto Zone etc. Get one with at least a 18Ah battery and leave the supplied wall charger connected while using it as a power source at home. You can connect directly to the jumper clips.
Note: Connect on the side the wire leads go to as the oppesite side is not hot.

When using you car battery at the field besure to start you car / truck after every couple of charges or you will kill your battery quick.

I use two 125Ah Deep cyle batteries in parallel, 250 Ah total as my field power source.


Charles

< Message edited by everydayflyer -- 1/7/2008 2:28:35 AM >

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RE: Help - A123 Astro blinky balancer issue! - 1/7/2008 2:44:21 AM   
everydayflyer



Posts: 889
Joined: 8/21/2005
From: Buchanan, GA, USA
Status: offline 		Follow up for post #6 A123 inbalance.

Real world example.

3S discharged to 6.5 volts. Connected to TP 1010C / 210V combo charge set for 10A.
Started charge and inbalance 0.124. Approx 1 min. into charge inbalance exceeded 0.200 and charger went into safety mode (0.300 mA charge rate). Inbalance was holding at 0.194 or so. After several minutes with inbalance not improving I stoped the charger ,disconnected the balancer and restarted charge ,still at 10A. When pack reached 10.5 volts I reconnected balancer(on the fly / during charge) and inbalance was 0.009. Charge complete without issue.


charles

< Message edited by everydayflyer -- 1/7/2008 2:45:23 AM >

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RE: Help - A123 Astro blinky balancer issue! - 1/7/2008 3:20:21 AM   
747



Posts: 252
Joined: 9/14/2003
From: Downingtown, PA, USA
Status: offline 		Great Real world example, I 'll keep in mind to balance after charging fully.

I disconnected my blinky now- I noticed that in my 5S a123 pack, 4 cells were bleeding slowly and the 5th one (lowest V cell) was also bleeding - it came to 3.07v from 3.20 and I didnt want it to go below 3v....!

How long would it take to charge my 5S1p a123 pack from my car battery ? Can I use my old jumper cables to connect to the astro charger plugs(for extra length from the car battery) , or would it be too much resistance ? What charge rate should I start with? Thanks

< Message edited by 747 -- 1/7/2008 3:24:11 AM >

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RE: Help - A123 Astro blinky balancer issue! - 1/17/2008 2:32:13 PM   
Rickochet


 

Posts: 25
Joined: 10/26/2006
From: Frankfort, KY, USA
Status: offline
quote:

ORIGINAL: 747

Great Real world example, I 'll keep in mind to balance after charging fully.

Hi 747, I just found this thread after posting an almost identical one on RCGroups. I put my A123 blinky on a new 3s pack and it did exactly yours did. My voltages were 3.12, 3.31 and 3.31. After hours on the blinky the two highest cells were down .002v then the lower cell started creeping down also. I then put it on the 109 A123 charger on .75amp charge and after about 20 minutes the the lights on the blinky started alternating. The voltages then were checked at 3.29. 3.30 and 3.30. I now have the pack on a 1c charge with the blinky on.

Edited: After a 1c charge with the blinky on I terminated the charge in stage 3 and checked voltages. Total voltage was listed at 10.8 volts, Cell #1 is 3.40, #2 3.92 and #3 is 3.42. I am not sure what is up with cell #2.

Edit #2: After an hour off of the charger with the blinky on cells are now 3.38, 3.39 and 3.38 so I think things have mellowed out.

< Message edited by Rickochet -- 1/17/2008 5:06:02 PM >

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RE: Help - A123 Astro blinky balancer issue! - 1/18/2008 1:58:05 AM   
747



Posts: 252
Joined: 9/14/2003
From: Downingtown, PA, USA
Status: offline 		Richochet,
Yes as Everyday mentions my imbalance is less after I chrg my a123s to max. I now balance after a full chrg and it takes less time to balance. Does your blinky (astro) go very random lighting on/off after balancing , is that how we tell the balance is complete?

Do you always chrg and balance at the same time? I chrg my pack at 9A rate.

What do you fly the pack with? Do you balance every flight?

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RE: Help - A123 Astro blinky balancer issue! - 1/18/2008 5:30:13 AM   
SinCityJets



Posts: 793
Joined: 11/13/2005
From: Henderson, NV, USA
Status: offline 		This is one of the nice features of the FMA CellPro 4S. It balance CHARGES, so it actually pushes current through the balancing leads, as opposed to drawing the high cell down. As ED says, it is MUCH faster to push the current (4amps) than it is to pull it down at 150-350 mah.

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RE: Help - A123 Astro blinky balancer issue! - 1/18/2008 11:00:24 AM   
Rickochet


 

Posts: 25
Joined: 10/26/2006
From: Frankfort, KY, USA
Status: offline
quote:

ORIGINAL: 747

Richochet,
Yes as Everyday mentions my imbalance is less after I chrg my a123s to max. I now balance after a full chrg and it takes less time to balance. Does your blinky (astro) go very random lighting on/off after balancing , is that how we tell the balance is complete?

Do you always chrg and balance at the same time? I chrg my pack at 9A rate.

What do you fly the pack with? Do you balance every flight?


To my understanding the blinky goes to random blinking when it is close to being balanced. When the battery is balanced all lights are supposed to go off. I am just getting into A123 and just built my first 3 cell pack and just charged it for the first time using an old Astro 109 converted with the new A123 chip. I plan to put them in and Easy Star and a Slow Stick. I then plan on putting some 4 or 5 cell parallel packs in some old 40 size glow planes I plan on converting. From another post by Charles I think the best thing to do is to forget about balancing for awhile and just go out and fly these packs for a bit then worry about balancing.

I am guessing that after this brief experience with the blinky and if balancing these is a real issue a