IMax B6_ balancing during operation

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pratikdas87   10 mW

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IMax B6_ balancing during operation

Post by pratikdas87 » Apr 27 2017 6:19am

Dear all,
I am trying to charge lithium ion batteries (NMC-graphite) with 3S1P configuration.
I am using a ImaxB6 for the charging and discharging process.
I would like to know if someone can tell me what kind of balancing is done by the IMaxB6.
Is it a top balancing (like passive balancing) or an active balancing?

Thank you very much,
Pratik

kingjamez   100 W

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Re: IMax B6_ balancing during operation

Post by kingjamez » Apr 27 2017 9:54am

It's resistor based balancing, it discharges cells to balance them.

-Jim

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dogman dan   100 GW

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Re: IMax B6_ balancing during operation

Post by dogman dan » May 01 2017 6:56am

Top balancing. You can watch it happen on your display. One cell gets high, charging stops. you will see that cell discharging, then charging re starts. The resistor will connect, and the high cell gets discharged. At a certain point, the circuit opens, and the resistor is not connected anymore.

When all cells are fully charged, top balanced, it will then stop the charge for good, and beep to be disconnected.

Other kinds of balancers will just have the resistors, and will discharge all cells to the same level as the lowest charge cell in the string. Those will balance at somewhere less than full, unless you put it back on a charger.

markz   100 GW

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Re: IMax B6_ balancing during operation

Post by markz » May 01 2017 5:41pm

I have the iMax b8+ and I have watched what Dan just described.
It takes a long time to finish.

It would have been best to step up to a 10S iCharger, but then why not just buy a Satiator.

Live & Learn

pratikdas87   10 mW

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Re: IMax B6_ balancing during operation

Post by pratikdas87 » May 04 2017 12:54am

kingjamez wrote:It's resistor based balancing, it discharges cells to balance them.

-Jim
Thank you JIm. really appriciated.

pratikdas87   10 mW

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Re: IMax B6_ balancing during operation

Post by pratikdas87 » May 04 2017 12:55am

dogman dan wrote:Top balancing. You can watch it happen on your display. One cell gets high, charging stops. you will see that cell discharging, then charging re starts. The resistor will connect, and the high cell gets discharged. At a certain point, the circuit opens, and the resistor is not connected anymore.

When all cells are fully charged, top balanced, it will then stop the charge for good, and beep to be disconnected.

Other kinds of balancers will just have the resistors, and will discharge all cells to the same level as the lowest charge cell in the string. Those will balance at somewhere less than full, unless you put it back on a charger.
Thanks dogman dan,
Indeed it is top balancing. thank you for the information. really appriciated.
Last edited by pratikdas87 on May 04 2017 12:57am, edited 1 time in total.

pratikdas87   10 mW

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Re: IMax B6_ balancing during operation

Post by pratikdas87 » May 04 2017 12:57am

markz wrote:I have the iMax b8+ and I have watched what Dan just described.
It takes a long time to finish.

It would have been best to step up to a 10S iCharger, but then why not just buy a Satiator.

Live & Learn
Hey Markz,
you are right about Dan. I also observed the same.
Thank you.

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dogman dan   100 GW

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Re: IMax B6_ balancing during operation

Post by dogman dan » May 04 2017 5:46am

A quicker way to balance with the b6 or similar chargers, is to do a quicker non balancing charge, then select any cell that is particularly low, and charge it as a single cell.

To do that, you need to make an adapter, so you can charge one cell through the balance plug. one end of the adapter fits your b6 main plug. the other end is just bare pins from a male jst plug. identify which female holes on the battery balance plug go to the low cell you want to charge, and connect with the adapter.

Then select single cell, 1s charging, and fill the low one. Get the pack within .05v of balanced is plenty good enough, if you are not practicing deep discharges below 3.6v per cell.

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Lash   100 W

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Re: IMax B6_ balancing during operation

Post by Lash » May 04 2017 6:14am

Thanks for this. Ive done dogman dan says and charged one of my parallell groups by itself. 1s10p of 30Q 18650s. The full pack is 18s10p. I have a pesky group (no6) that has gone down .2v and .3v and beyond. Obvioulsy this cuts my ride short as low voltage protection for this group kicks in. I have the adappto MAX-e and charge coil and server PSU to do the charging.

I recently had the pack apart and was using aligator clips with a tiny charge pcb from a bike light charger to try and charge it. I brought it up a bit, but was not sure what the hell the little tiny pcb was doing, so stopped it after 10-15 hours worth. the group got up around 4.0v but maybe it still wasnt charged properly?. I repackged the battery back up and now that group says 3.9

The problem with the adappto is it takes ages to balance. (I have it to start balancing at 4.0 and to stop at 4.1 a cell) Maybe I'll chnage the balance voltage to start lower so it picks up this group?

Otherwise I might undo the battery covers again (annoying) and get a B6 charger to charge that one group properly and see what happens. Is the Imax b6 from hobbyking (in australia) a good option for this. Anything else to consider?

All the cells measured close to 3.7 when it was naked so hopefully its just a low group and not a dud cell. (i didnt balance charge for a year -- noob)

Thanks.

P.S welded packs are pretty annoying for this. This is where lipo reigns supreme I guess, unless you have a compression welderless 18650 pack...

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Lash   100 W

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Re: IMax B6_ balancing during operation

Post by Lash » May 05 2017 2:36am

Ive just re-read what dogman has said, charging a single group through the balance plug is a novel idea. this might save me from tearing all the shrinkwrap and padding off the battery again.

pratikdas87   10 mW

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Re: IMax B6_ balancing during operation

Post by pratikdas87 » May 05 2017 4:59am

dogman dan wrote:A quicker way to balance with the b6 or similar chargers, is to do a quicker non balancing charge, then select any cell that is particularly low, and charge it as a single cell.

To do that, you need to make an adapter, so you can charge one cell through the balance plug. one end of the adapter fits your b6 main plug. the other end is just bare pins from a male jst plug. identify which female holes on the battery balance plug go to the low cell you want to charge, and connect with the adapter.

Then select single cell, 1s charging, and fill the low one. Get the pack within .05v of balanced is plenty good enough, if you are not practicing deep discharges below 3.6v per cell.
Dear Dan,
Thank you again for the advice. it seems a very good method for quick charging batteries in series. I have a question regarding your deep discharge comment. As i have understood, lithium ion batteries are capable of deep discharge. is there aspecific reason you have mentioned 3.6 V. i used to think below 3V is deep discharge for lithium ion batteries.

I have another question dan, I hope you can guide me with this. I am making a battery pack for myself using 18650 cells. I want to make a 3S5P system. my question is can i make 3 blocks of cells each having 5 cells in parallel, and then connect them in series?
normally, people advice to put sells in series first then to connect parallel cells. in my case, although each cell will not be connected to it's next cell in series, each block will be in series with next block. Could you please suggest me if i will face some major issues with my design.

With regards,
Pratik

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dogman dan   100 GW

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Re: IMax B6_ balancing during operation

Post by dogman dan » May 05 2017 5:56am

To clarify, I mentioned 3.6v because I made a bad assumption that you were using lico, or RC lipo. They can be discharged deeper, but at about 3.65v lipo is just on the verge of going over the discharge cliff, where there is not many wh left.

What I meant to convey, was that if you keep any chemistry voltage above the steep drop in the discharge graph, you have less need to balance again, and less need to be balanced to .01v

With my lipo, I tend to charge to 4.15v, and mostly, stop discharging around 3.7v. This type of use pattern leaves me needing to balance the pack only 4 times a year.

pratikdas87   10 mW

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Re: IMax B6_ balancing during operation

Post by pratikdas87 » May 08 2017 11:27pm

dogman dan wrote:A quicker way to balance with the b6 or similar chargers, is to do a quicker non balancing charge, then select any cell that is particularly low, and charge it as a single cell.

To do that, you need to make an adapter, so you can charge one cell through the balance plug. one end of the adapter fits your b6 main plug. the other end is just bare pins from a male jst plug. identify which female holes on the battery balance plug go to the low cell you want to charge, and connect with the adapter.

Then select single cell, 1s charging, and fill the low one. Get the pack within .05v of balanced is plenty good enough, if you are not practicing deep discharges below 3.6v per cell.
Thanks Dan :D

markz   100 GW

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Re: IMax B6_ balancing during operation

Post by markz » May 09 2017 1:50am

Does anyone actually know what the 4 digit number means on the bottom right of the display?
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amberwolf   100 GW

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Re: IMax B6_ balancing during operation

Post by amberwolf » May 09 2017 2:43am

Dunno about yours (you'd have to check it's manual) but on the Accucell6 and the Venom I've got it is mAh.

Also, it's a 5 digit number. ;)

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