Parallel Charging Lipos

[steve fh]

Bought a second 4000mah Lipo last week and then promptly ran into the issue that after evening flying there was hardly enough time in the evening to charge then one after the other ready for the morning

As parts to finish wiring in the lamp pod for the rally car did not arrive yesterday i spent the evening making up leads so i can parallel balance charge my two lipos

So after this mornings flying session i now have two lipos charging at the same time. My Accucel 6 is a bit short of grunt as it only goes up to 6A and lipos add up to 8000mah. That said it';s faster than back to back and charging under 1C is no bad thing.

Not high on my purchase list but what charger would people recommend if i wanted one with a bit more grunt once i have more lipos ?

[XH558]

I had the same problem - waiting for one battery to charge etc etc  ...

So I bought one of these....

http://www.ebay.co.uk/itm/Parallel-Deans-Charging-Board-for-6-Packs-T-Plugs-Connectors-/390442946498?pt=UK_ToysGames_RadioControlled_JN&hash=item5ae8368fc2

And it works REALLY well with my charger ....

http://www.giantshark.co.uk/power-b606-balance-charger-lipo-nimh-battery-p-406285.html

I have charged 6 batteries together at 1C and it';s definitely quicker and they all balance as they charge 

[steve fh]

Thanks.

Good spot re the balance board, all the ones i saw were from China hence making up a lead for a quick fix.

That charger is the same units as the Accucel 6 i have so it';s quickly out of it';s depth trying to charge multiple 4000mah

[XH558]

Yeah - most of mine are 2200mah - so it does well for me ... it was mostly about the parallel charging board though 

[steve fh]

I was considering a second Accucel 6 as they are cheap and do a god job as far as i can tell and also have the benefit of reducing the chance of having no charger in event of one going sick.

[XH558]

Well ... now that';s strange ....having now looked at the Accucel 6 it looks REMARKABLY similar to the X Charger I linked to from Giant Shark above

I would hasten a guess that they are from the same factory and are badged accordingly 

 

[teslahed]

They churn those things out everywhere - you can buy them under about a dozen different brand names.

They all seem to work pretty well though which is the main thing. I had one fail after 12 months of near continuous use - so i just bought another one exactly the same.

[dp106]

I had the same problem - waiting for one battery to charge etc etc  ...

So I bought one of these....

http://www.ebay.co.uk/itm/Parallel-Deans-Charging-Board-for-6-Packs-T-Plugs-Connectors-/390442946498?pt=UK_ToysGames_RadioControlled_JN&hash=item5ae8368fc2

And it works REALLY well with my charger ....

http://www.giantshark.co.uk/power-b606-balance-charger-lipo-nimh-battery-p-406285.html

I have charged 6 batteries together at 1C and it';s definitely quicker and they all balance as they charge 

how do you program your charger when using that then?

[steve fh]

how do you program your charger when using that then?

The packs need to be the same cell count (IE 3S, 4S etc) but can vary in capacity and charge state (I did read some where  that it';s best done with packs close to same charge level)

It simply connects the balance taps and main feeds in parallel so the charger sees them as one large pack and averages out the cell voltages.

You add all the individual pack mah capacities together to get the total capacity then calc 1C in the normal way.

IE my two 4000mah packs total 8000mah so 1C is 8A (my charger can only do 6A max so actually i';m at under 1C)

[XH558]

I don';t programme anything  I just plug the parallel board and it';s balance lead into the charger - then plug all the batteries and their balance leads into the board - tell it to charge at 1c for whatever battery packs are connected and when it';s finished I checked each battery and they are all 12.6v with exactly 4.2v per cell per battery.

Before - when I plugged in a single battery without the board and no balance lead it finished at say 12.6v but each cell was perhaps marginally different in individual voltage. I then had to set the charger up to do a balance.

Thus ergo I assumed (which makes an Ass of U and Me) that the cells were balancing as they charged through the parallel board .... :embarrassed

I';m probably wrong - but I don';t care because it seems to work    

[steve fh]

I think the more packs you add the more the internal resistances average out so you get a more balanced charge

[XH558]

Yeah - what he said