Discussion About parallel charging of Lixx / PB packs.

[kgfly]

You have to connect all 4 sets of balance leads in parallel but only one connection to the charger is needed.

[NX-687]

Can you slip all those lipo s ( in post #1 ) in to a lipo sack or container, so that you can leave and come back when they are done ( with safety)

I dont want to have a flame out in my computer

[Julez]

Originally Posted by GreenBar0n

[]
Is there anything else I should be cautious or aware of when charging in parallel?

Will the life expectancy of the packs be diminished in any way?

Thanks for your kind words!
The more packs you charge in parallel, the more you should make sure that the packs do not differ in state of charge.
Life expectancy is not influenced in any way.

Originally Posted by NX-687

Can you slip all those lipo s ( in post #1 ) in to a lipo sack or container, so that you can leave and come back when they are done ( with safety)

I dont want to have a flame out in my computer

Yes, this is possible, but you need either a large lipo sack, or longer balancing cables. I'd say 30cm (1ft) will do.

As a kid I found an ammo box of the german Wehmacht, perhaps I will use this as a charge bunker, should I get into frequent LiPo charges next season. At the moment, I almost only charge A123.

[NX-687]

Can I parallel a 400 Mah 3s and a 1500Mah 3s at 1.9 A

Both in same state of charge 11.3 V

And not be overcharging the little 400

Amp wise ?

[Julez]

Yes, this should certainly be possible.
Just think what would happen if you replace the 1500mAh pack with 3 pieces 400mAh packs. You'd have about the same capacity, but I see no reason why one particular pack should overcharge.
Now if you combine the 3 400mAh packs into the 1500mAh pack, there is still no reason why the 400mAh pack should overcharge.

[NX-687]

Thats just great

All my 3S packs at once, that tends to make things easier in the battery

department when preparing for the weekend , of course with proper

protection around the batteries in case of accident

[Ramotny]

Hi Julez,
may I ask why on first picture the packs are connected from both sides ie. with balance connectors AND load connectors? Is the load connector for charging also?

[DanT]

On my setup it will only balance all the cells if I charge in series.
I think it's because of the type of charger I use? I'm using a Turnigy Accucell-6 charger with a CCB-723TPQF board .
http://www.hobbycity.com/hobbycity/s...CB-723TPQF.jpg
If I try and charger in parallel ( say , two 3 cell TP 1320 ) using this setup the charger will only show that 3 cell are being balanced not 6 cell. So I guess I would have to have a charger that charges using the balancing taps to charge in parallel ?
DanT

[mrforsyth]

Originally Posted by DanT

On my setup it will only balance all the cells if I charge in series.
I think it's because of the type of charger I use? I'm using a Turnigy Accucell-6 charger with a CCB-723TPQF board .
http://www.hobbycity.com/hobbycity/s...CB-723TPQF.jpg
If I try and charger in parallel ( say , two 3 cell TP 1320 ) using this setup the charger will only show that 3 cell are being balanced not 6 cell. So I guess I would have to have a charger that charges using the balancing taps to charge in parallel ?
DanT

A charger that charges through the balance taps is not necessary. You simply have to parallel the balance taps in addition to the main charge leads as shown in Julez' first post in this thread. All cells will be in balance upon charge termination.

Attached is a photo of one of my parallel cable sets in action.

Mark

[GreenBar0n]

mrforsyth,

Are you saying you don't use a separate balancer after charging in parallel? Not even once in a while?

Do you use the packs individually or all together?

[mrforsyth]

Originally Posted by GreenBar0n

mrforsyth,

Are you saying you don't use a separate balancer after charging in parallel? Not even once in a while?

Do you use the packs individually or all together?

My charger is a balancing charger and the paralleled balance taps are connected to the balance port on the charger during the charge cycle. All packs are always perfectly balanced at completion of charge.

My packs are discharged individually. Voltage after discharge is typically around 11.3-11.5V. Also, I frequently charge 3S 5000mAh packs in parallel with 3S 2100mAh packs. As they're in parallel and at the same voltage, this is completely safe.

Mark

[Julez]

Originally Posted by Ramotny

Hi Julez,
may I ask why on first picture the packs are connected from both sides ie. with balance connectors AND load connectors? Is the load connector for charging also?

Balance connectors are connected for balancing, and the main cables must be connected for charging.

On my setup it will only balance all the cells if I charge in series.
I think it's because of the type of charger I use? I'm using a Turnigy Accucell-6 charger with a CCB-723TPQF board .
http://www.hobbycity.com/hobbycity/...CCB-723TPQF.jpg
If I try and charger in parallel ( say , two 3 cell TP 1320 ) using this setup the charger will only show that 3 cell are being balanced not 6 cell. So I guess I would have to have a charger that charges using the balancing taps to charge in parallel ?
DanT

The charger will still balance all cells when both the main leads and the balance connectors are connected in parallel. All the charger "sees" is one bigger pack (capacity-wise), but the same cell number.
One can charge 100 pieces of 3s packs in parallel, but the charger will still only "see" 3 cells.

[not.likely]

This is a great thread julez - very well done the pictures are great too!
So really what is happening here is that, with for example 2 x 3s packs connected in parallel, and the balance connectors also paralled ( in the right configuration of course ! ) the charger sees 1 big 3s pack, and although it also sees 3 cells in that pack, each cell it "sees" is really 2 x cells connected in parallel, and we are relying on the fact that each pair of cells will even each other out and therefore be balanced ?
I think you are also saying that packs of different capacities are also fine to do like this ( same cell count of course ) and they do not necessarily have to be at the same state of charge when they begin charging. ?
I am going to make up the balance plug parallel connector PCB that you show, and laso parallel the main leads too because I am likely to be charging like this - but at high rates so the balance wires will be unhappy with large charge currents.
Again...nice one Julez!!

[NX-687]

What is your opinion on putting 4Amps down the balance wires to charge your batteries

Im beginning to think its OK now , when first I heard, I didnt like the idea of putting that current down those small wires

[mrforsyth]

Originally Posted by NX-687

What is your opinion on putting 4Amps down the balance wires to charge your batteries

Im beginning to think its OK now , when first I heard, I didnt like the idea of putting that current down those small wires

Should not be a problem at all. The Cellpro and others charge at 4 amps via the balance connector without issue. The only consideration is that it may take a little longer to complete the charge as there will be greater voltage drop in the balance taps and your charger will spend more time in CV mode.

I personally prefer to have all of the main connectors handling the charge current and use the balance connectors to monitor individual cell voltage and provide balancing. Not entirely necessary, just my preference.