Lipo Balancing or just charging?

[Basstronics]

Ok I think i have myself thoroughly confused now.

For the last two years when I charge my batteries I have done so with a "Charge" setting.

I have noticed the "Balance" setting but it always seems like it takes forever.

So I went to balance charge a 2S 5000 pack (HK pack). First time on the charger. It was on the charger for a total of 175ish minutes... I bet the last 120 minutes was the charger trying to balance the packs. One cell is at 4.18 the other 4.20

I charged the second pack with same results.

However if I just goto "charge" option it stops and not an endless charge like.

In both instances of Balancing I shut the charger off manually.

I noticed this same issue with a 3S battery.

Is the charger junk or the batteries?

[Boaterguy]

It takes me a little longer too, but not 175 minutes!!
what charge rate are you using?

[Basstronics]

1C, 5A on these packs.

The last forever was .1A charge trying to balance.

[Boaterguy]

what charger?

[Basstronics]

http://www.r2hobbies.com/eng/proddet...prod=rcps61313

[Boaterguy]

Sorry, no clue.

[tiqueman]

Yeah, 175 minutes isnt right. So if I understand your post #3, your charging it at 5 amps correct? And does it really get up to 5A while charging? Ive heard of some that dont have the "umph" amnd it says 5 but may max out at 2 for such packs? Other than that, Im clueless.

[siberianhusky]

If you have a DVM check the actual reading of the cells against what the charger is telling you.
I think that is a 50 watt charger, it might not reach the full 5 amps but it should be very close. It shouldn't take an hour to balance charge a 2s 5000mah pack, even if it was discharged too far. Could take a real long time to charge 3s and above packs as you would not be able to hit a 5 amp charge rate.
Being an inexpensive charger I would check to make sure it's calibrated, if it's doing the same thing on multiple packs I would suspect the charger.
I got one of those cheap HK battery checkers for 2$ to fill out an order, it always tells me cell 2 is .02V less than the others. There stuff is cheap but I don't exactly trust it 100% to be accurate.

[Basstronics]

Thanks for the response guys.

In fact both 2S batteries were having the same exact issue on cell 1. Im leaning towards the charger at fault also.

How do I check each cell? That small white balance plug? I would assume the black is ground and the colors are positives per each cell?

I could check and that will tell me 100%.

As for the actual charge rate, it did say it was charging at the full 5A. With the "Charge" and the "Balance" options they both will start off at the max selected charge rate then back down as charging progresses.

[Boaterguy]

Thanks for the response guys.

In fact both 2S batteries were having the same exact issue on cell 1. Im leaning towards the charger at fault also.

How do I check each cell? That small white balance plug? I would assume the black is ground and the colors are positives per each cell?

I could check and that will tell me 100%.

As for the actual charge rate, it did say it was charging at the full 5A. With the "Charge" and the "Balance" options they both will start off at the max selected charge rate then back down as charging progresses.

the red is positive, the one next is cell one (4.2V) the next is both (8.4V) (these voltages are fully charged)
it continues like that for larger packs
http://www.offshoreelectrics.com/lipo.php

[sanyijr]

1C, 5A on these packs.

The last forever was .1A charge trying to balance.

One additional thought: You say that the charger trickles down from 5A......to 0.1A but spends most of the time (or the longest time) on the lower 0.1A. I am not positive on why that is, but the bulk of the charge is complete once you drop off to 1A or so of charging. the 0.1A is "topping off". If you look at total input into packs (if your charger does that) once your charge rate drops off from 5A, it should be 95% or so of total capacity....

Also, the balancing is done at the start of the charge on most chargers and then constant monitors thoughout. I have hooked up the add-on balancers like the great planes balance adapter and ALL the balancing is done in the first 5-10 minutes. (this obviously depends on how out of balance they are and balance discharge rates, but still, should be in first 10% of charge time I would think) But after the first few minutes, the balancer never does any more balancing. I think charging a 1C is much more stable and clean than high capacity discharging. That is what causes imbalances.

The fact that it hovers at 0.1A charge is odd. Kind of like you are bleeding off current, just enough to not reach full 4.2V..... But as mentioned by others, looks like charger, not batts if multiple sets have been run through..... odd.....

[Boaterguy]

It could balance differently, ie. charge up to 4.2 volts and then discharge at .1A on the cells that are above the lowest voltage.

[785boats]

Basstronics.
I have a couple of older & abused packs that won't trigger the cut off after spending forever at 0.1A. But all the other packs work fine on my charger which uses basically the same program & functions as yours.
What I do with them is use the FAST CHARGE setting. The only difference is that the cutout setting is at about 0.4A instead of 0.1A. It just short charges the battery by about 150-200ma. But it's a lot quicker as the cutout works.
Or you could just reduce the timer setting in the menu to the time it takes to charge a depleted pack to the point that the charger first hits 0.1A. You'll have to watch a couple of charges to gauge that .
But don't forget, larger capacity & higher cell count packs may need more time than your 2s packs.
I've set my timer to 90 minutes so even if I do charge the suspect packs in the BALANCE mode it's not a problem.
If your charger isn't sensing any of your packs (especially new ones) in the balance mode I would say that there is an internal sensitivity setting that is not right, & I don't think it is adjustable.
All the best.
Paul.