dont yell at me

[whitmanink]

sorry guys , don't yell at me to read more , because I have and im confused ,, my charger 306b I charger , when I parellle charge my lipos I balance charge and I make sure packs are bout the same volts , and about 8 min into charging 30amp(15amp a pack) an error goes off , the voltage is too unbalanced , and my packs are at about 4.10 an the other pack is like 3.95 , there new packs (less than 15 charges) why is this doing it? I got the combo from progressive rc so I got boards with fuses and all for safety , should I make a video then showing what im doing and what happens when the error sign comes up? do I not charge in balance mode?

[JonJet]

What battery are you charging...specifically?

[whitmanink]

revoletrix 60c ,5000mah ( 6c charge) from amain

[JonJet]

Have you tried charging one battery at a time?

[BigEddie]

Agree with Jon try one battery at no more than 2C or 10 amps this will determine if there are any pack issues. If ok charge at 1.5 C or 15 amp total for the two packs in parallel once you know balance has been acheived.
I myself do not charge any battery over 2C even at the field.

[ahahn]

I would be suspicious of the connections somewhere (sorry for being so vague).

The charger is putting out 30A into the main leads. If for some reason, one set of these leads is making a poor connection (maybe a bad fuse or connector), you can develop a high (relatively speaking) resistance on the charging leads of that one pack.

Now since the balancing leads are also connected together, which means each cell in a pack is linked to the corresponding cell in the other pack, the cells will try to equalize by current flowing through the balance leads. But these balance leads aren't meant to carry a high amperage at all. The charger is monitoring these balance leads to keep track of each cell (or pair of cells if you are charging two packs in parallel), and during the period it looks, it doesn't expect that the leads are carrying any current. My guess is they are being fooled/confused by this.

Parallel charging works great in general, but that is assuming each pack's hookup is basically identical. If that isn't true, then it can be problematic.

I suppose I'd check continuity on the main leads, especially around any fuses to make sure they are ok and not burned out (for example).

[Gregor99]

New packs may need 5 to 10 cycles before the cells charge evenly. Parallel charging as well as charging at higher levels can exaggerate cell differences in packs that are new. The 306b does not balance during the main phase of the charge. Balancing only starts when one cells reaches 4.2v. So the charger is not helping correct the imbalance.

Like the guys said, I would try charging them as singles at a slower rate. At least for the first 10 cycles. This will also help balancing at the end since the balance current is 500ma. You may find that even charging as singles, the balancing takes a while. That's normal for chargers with modest balance current. If the balancing phase ends up taking a long time, you can change the balance start point from CV to Storage. Balancing will then start at 3.8v. Once the packs are broken in, then you can move the setting back to CV.

[Slyster]

Agreed! Cycle 5 times singly. Never parallel charge new packs. Great advice above let us know how it all works out . * subscribed

[RedOctobyr]

I'd connect a single pack to each location of the parallel board. Main and balance lead. Make sure the charger shows the same thing for every single position, for the main voltage, and the voltage of each cell.

If the test looks good (same #'s everywhere), I'd also do it after you get this error.

I had a bad fully-fused board, and the symptom was bizarre balance-lead voltage readings, but not all the time, and sometimes not right away.

I figured it out by doing the single-pack-at-each-location test, then found strange per-cell readings for one location. A replacement board fixed it.

[Gregor99]

Originally Posted by RedOctobyr

I'd connect a single pack to each location of the parallel board. Main and balance lead. Make sure the charger shows the same thing for every single position, for the main voltage, and the voltage of each cell.

If the test looks good (same #'s everywhere), I'd also do it after you get this error.

I had a bad fully-fused board, and the symptom was bizarre balance-lead voltage readings, but not all the time, and sometimes not right away.

I figured it out by doing the single-pack-at-each-location test, then found strange per-cell readings for one location. A replacement board fixed it.

+1 Do this before cycling the packs. Just to be sure the hardware is OK.

[whitmanink]

yea single the charger charges fine ,hmm maybe my lipos arent so close ,. its nice out I already got 6 runs in , so I will have time to fiddle ,, I will report back

[JonJet]

The recent remarks got Me thinking that as the packs age, there might be a difference in after-flight voltage that is enough that the balancer cannot equal them out given it's current rating...

Or, if the pack was flown an extra minute or for less time than the other pack(s) in the parallel ports

It might not be a bad idea to fly all your packs then charge them individually, keeping record of start voltages after the same amount of flying time

Variations like you stated in post #1 would not be a problem with much smaller packs that needed / didn't need the current limit to balance them in the first 8 minutes

A Larger charger might also cure the immediate voltage imbalance

[RedOctobyr]

Originally Posted by JonJet

Or, if the pack was flown an extra minute or for less time than the other pack(s) in the parallel ports

If parallel charging, this isn't a concern for the balancer. Once you connect them in parallel, they will self-equalize.

This is safe for small voltage differences. Like one pack at 3.80V/cell, another pack at 3.84V/cell. Some current will flow between them, and they will meet at 3.82V/cell, which is what the charger will see. It does not need to use the balancer to do this, nor *can* it, the charger only sees a big cell at 3.82V.

This can be dangerous for large voltage differences. Like accidentally plugging a charged pack together with a discharged pack, and getting a huge current flow between them. They'll still self-equalize, but you might melt the balancer wires as it happens.

[whitmanink]

If parallel charging, this isn't a concern for the balancer. Once you connect them in parallel, they will self-equalize.


this is why I am concerned

[JonJet]

My concerns above were in the case of the difference in voltage in the OP's case...

In a 5000 mAh battery, the balance-difference would require possibly more than the charger could supply to the lower-voltage pack in 8 minutes.

No?

[RedOctobyr]

I should have phrased my post better. It's kinda self-evident, but:

All of the same-number cells will self-equalize, when connected in parallel. All your cell 1's will come to the same voltage, all your cell 2's will come to the same, etc.

All the cell 1's can still be 3.80V, and cell 2's can still be at 3.90V, of course. That's where the balancer will come into play.

So if the cells within your packs are all balanced, then you don't need to worry if you flew pack A for 4:00, and pack B for 4:30, etc. If all the cells in A are 3.75V, and all the cells in B are 3.79V, then when you connect them in parallel, the charger will see a big pack at 3.77V/cell.

But I think we're getting way ahead of ourselves. An iCharger, by default, won't even start to balance until the first cell reaches 4.20V. So it shouldn't have even been trying to balance yet, if one was only at 4.10V.

- Please check the board first, as I described previously. That might be your problem right there.

- If not, what was the exact wording of the error message, if you remember?

[JonJet]

Ahh...better stated an now understood...

Thanks !

[whitmanink]

ok today im gonna get more flying in , so heres whast I plan to do ,
first , I will charge all lipos at a nice slow 4.5amp charge till they are 3.80 or all the same volts in each pack, then im gonna parell charge and set it for 30 amp , 15 amp a battery,and see what happens , then if and when the error comes up I will write it down word for word ,, I checked my fuses and they are all good , but ill switch them just in case,,,, and after I come back with my findings and we still are at a loss , I will do a video and maybe some1 can catch whats going on,,,,,,,thanks guys for the quick responses

[RedOctobyr]

I'm more interested in the self-resetting polyfuses on each balance connection. The main, blade-type fuses are less likely to be the cause of trouble, I'd expect.

Did you check each position with just a single pack connected, checking the main voltage, and the per-cell voltages?

[whitmanink]

ok guys I figured it out, ready for this? I never changed my mah cutoff , sooo when it hit 5000mah it cutoff saying it hit capacity , that was a blonde moment