I have the Bantam 902 with the interlink to ballance my 12S packs, but as the BC8 this is not a true ballance charger, as Edmond says it just discharges as it is charging to ballance the cells, with a ballance charger which charges through the ballance leads you are only charging one cell with the smaller cable, admittedly the interface cable between two cells is taking twice the charge of the single cable on the outside cell, but in any case the charge input is divided by the number of cells in the pack, so a 3S pack charging at 10amps is only taking 3.3amps per cable to the outside cells and a possible maximum of 6.6amps to the internal - + connection, the Tenergy ballance charger is only rated for 6amp charging so the current taken by the ballance lead is even less, I have not seen a ballance lead yet that would not be capable of taking that load.

 Mike

Eric Smyth wrote (see)

Has anyone had a crash that they can definitely attribute to unbalanced cells? I wonder!

Personally I balance my cells when a check shows a difference of more than 0.03v.

No special reason for this it just seemed reasonable to me at the time!

Its more a question of trying to prolong the life of your very expensive packs, as they get further out of ballance they become more inefficient, as the cells will not discharge at the same rate as they have different capacities, therefore the out of ballance gets worse and the performance suffers more, untill eventually one cell will be so far out of ballance it will not recover to its full capacity when charged and that's the end of the efficiency of the pack.

 Mike

Eric

I have practiced balancing my lipos for the last few days now. At first it was not easy due to the radius-ed ends to the battery, although it is easy if laid on their side (no need to balance). I have found that after a prolonged session of flinging, that the packs can get quite flat ends, which makes balancing on end much easier.

I will shortly be going to Aberdeen to visit my daughter via M6 etc., (running the tax raising speed trap gauntlet of varying speeds, there is one section that is 50mph for about 1/4 mile, with two cameras, then back to 70). I will practice my Highland fling there. Although it is technically not the Highlands, except for deliveries, when it is.

I no ow our fiend feels abart pour spellin, as uffers is to lasy to use spell checker. As I dont need need it, nar worry.

Erfolg

Matt Hackers wrote (see)

I have a CELLPRO charger that automatically balances and charges up to 4 cells and in some cases it can restore over discharged cells.

I think the Cellpro is a charger ballancer in other words it charges through the main negative and positive lead of the battery and ballances indipendantly, although microprocessor controled this is not true ballance charging.

 As explained earlier a true ballance charger charges through the ballance leads without the main negative and positive leads connected too the charger, they are in effect seperate chargers for each cell, microprocesser controled to ensure each cell is ballanced as it is charged though its own lead, I hope that is clear.

 Mike

Mike

The CELLPRO charger does charge through the balance leads, in fact it is the only way you can connect a battery to it.

Matt

Mike

Check out the charger by going to  www.aurorra.co.uk

Matt

The Cellpro charger on the above link has positive and negative connectors on the front case, why does it need these if it charges through the ballance leads?  Please do not think I am trying to be awkward I just want to know how many true ballance chargers are out there.

 Mike

 EDIT:  Sorry you have the 4S which does look like a true ballancing charger, so we now have the Tenergy, Cellpro and Orca, it seems more and more are becoming available, its a shame that they are all only capable of charging four cells.

Yes , it is a shame but at the present time my maximum cell count needed is only three cells so I don't have a problem at the moment but in the future, maybe???

Matt

Mike

That 10S charger at AURORRA will charge either a pack of 10 cells or two packs of 5 cells. I think you will find the connections for the balance leads on the charger are in the righthand end white coloured the same as on the 4S. I don't Know what the connections on the front face of the charger are for.

Matt

Matt

 It looks like they are for charging through the main leads and the ballancer is just a microprocessor to ballance whilst charging, its the same with all of the chargers over four cells at the moment, my Bantam 902 will charge 12S in any combination of packs and it links to the PC, you can check individual cell voltage either on the charger by scrolling through or on the PC screen, its as good as any of the others out there at the moment maybe a little bit better as it also charges A123's which I use as Rx packs in my bigger planes.

 Will keep looking for a ballancing charger rather than a charger ballancer, strange how the description gets confused by lots of manufacturers.

 Mike

Before buying my present balancing charger (IMax 6) iused a lipo charger with an inline balancer (Overlander).

The inline charger definitetly charged via the balance lead, as there was no other way.

I did not see this as very satisfactory, certainly not the answer to a maidens prayer, for the following reasons.

• On large capacity batteries +2000mah batteries took to long. Three or four hours, not spectacular on small capacities 500mah either.
• The final balance between cells was not as good than the IMax 6.
• Balance method often did not reach 4.2 v per cell.

I am quite happy with these balance chargers that use the power leads in addition to balance lead.

I balance every time because it is almost as quick at 1C to balance as not balancing.

Regards

Erfolg

Ultymate

Once you get above 5S the inballance of the cells after discharge needs to be addressed, even though the cells are all of the same C rating they can have slightly different discharge charicteristics, IMO on my 10S packs it is essential to ballance on each charge, if only for piece of mind because of the cost of replacement.

Erfolg

As you say most modern LiPo's will take a 1C charge rate, therefore it should only take a maximum of an hour to charge any pack with that capability, if the charge is going through the ballance leads the ballance is done automatically and therefore will not take as long as a charger that does it as an afterthought, that's why it took three to four hours to chage your 2000mah batteries. Most packs should not be discharged to thier fully flat state and so they will charge quicker than an hour at 1C, personally I only charge at 1C in the field, back in the hanger I charge at 0.5C, treating them with respect I still have a pair of 5000mah 3S2P from FlightPower that is gigantic, heavy and has a carbon cover, but still serviciable after 4.5years and 250 cycles, can't say the same for the cheaper branded ones though.

Mike

Perhaps a further explanation is in order:

 On a charger that chages through the main leads and has a ballancer either attached or internal, the over charge that causes the inballance is already in the pack, the ballancer acts as a voltage dump to take excess voltage out of the overcharged cell to equalise with the other cells being charged, this is normally disipated as heat, in most cases the over charged cells are not receiving any charge during this process, hence a longer charge period waiting for the dump to finnish before re commencing charging.

On a charger which charges each cell individually through the ballance lead only, each cell is monitored through an individual microprocessor for its voltage and if one or even two cells get in front of another cell in voltage terms those cells get a reduced charge rate untill the under voltage cell catches up, quicker and more efficient.

 Mike