Charging Lipos in Series

[T Nissen]

When I would run a 12 cell NiMh setup I always ran two 6 cell packs in series. I used designated packs for boats and only ran them together as a set. When I charged them I never had a problem charging the packs in series as if they were one. I was wondering if you can do the same with Lipo packs assuming you balance them before a charge. So if my 4S setup was made up of two 2S packs, could I connect the 2S packs in series and charge them together?

[vasy]

Yes, but don't do it.
With lipo it is best to charge parallel.
Read here: http://www.rcgroups.com/forums/showt...allel+charging

Page one give you all you need the rest is crap and opinions :)
Works well. Best is that all you need to match is cell count and only roughly the charge level. Capacity is of no importance.

The best part, make a 10 battery adapter, start charging in the evening and all done by the time you wake up. (just make sure if fire does happen you don't burn down the place. Place batteries in lipo bags or ceramic containers.

[red6]

I have 2 4s packs I charge in series for 8s but I have a balancer that will go up to 10s.

[vasy]

series only works well if you use packs at the same time and you can't really go past a few packs at a time and they MUST be the same. charge difference and capacity, charge state will f*ck you right over. With parallel, you face non of the issues. So no point to risk in my books. I used to do some parallel but no more.

[RaceMechaniX]

IMO, you never want to charge lipo packs in parallel. Forget what you know about charging NiMH and NiCD's it does not apply here.

Charging lipos in parallel without a coupled balancer (i.e. one that is matching all cells to the same voltage, not just cells in an indivudal pack) is asking for potential fire.

The safest way is to charge individually with a dedicated balancer. If you want to charge two packs at once, the only safe option is in series (4S+4S=8S) with an appropriate balancer linked like the Hyperion LBA10. For example, if you have a 6S charger and two 3S packs, you can charge the two in series for a total of 6S with the correct balancer.

You should not charge two packs in series if the packs have dissimilar charge levels, different capacities or are of different chemistries, etc.

There are too many do and don'ts of lipo charging so play it safe and charge 1C and one pack at a time.

My 2 Cents,

Tyler

[vasy]

IMO, you never want to charge lipo packs in parallel. Forget what you know about charging NiMH and NiCD's it does not apply here.
Tyler

Sorry bud, you are way off here. Parallel works very, very well. With hundreds of people doing it, I'd not say never. Series is where you have a BIG potential problem.
With parallel, balancing is super easy and you can connect all different pack of different capacity (not cell count) and it works.
Using some sense I'd stay away from charging batteries that are very different in charge states or internal resistance but the rest is ok.

[RcBum]

Sorry bud, you are way off here. Parallel works very, very well. With hundreds of people doing it, I'd not say never. Series is where you have a BIG potential problem.
With parallel, balancing is super easy and you can connect all different pack of different capacity (not cell count) and it works.
Using some sense I'd stay away from charging batteries that are very different in charge states or internal resistance but the rest is ok.

Hi so is there a problem with running lipos in series EG 2 3s = 6s ??
thanks

[RaceMechaniX]

It may work fine for a park flyer, but I would never risk it on a $200 battery. At least in the boating world I have never seen anyone charge in parallel with the excpetion of charging identical packs (brand, C rating, capacity & SOC) with synced balancers and this is rare.

The short and sweet answer is "Don't do it" as you pointed out.

Tyler

[vasy]

Hi so is there a problem with running lipos in series EG 2 3s = 6s ??
thanks

No. No problem. If you run them in series, charging in series also works well.

[vasy]

It may work fine for a park flyer, but I would never risk it on a $200 battery. At least in the boating world I have never seen anyone charge in parallel with the excpetion of charging identical packs (brand, C rating, capacity & SOC) with synced balancers and this is rare.

The short and sweet answer is "Don't do it" as you pointed out.

Tyler

This is safe way i know to charge multiple batteries.

I and $1000 worth of batteries on my charger, totally disagree with your statement.

If you read the post it gives a very good explanation why it works, why different batteries, capacity and C ratings work just fine and why charge level is not as important as in series charging. It also balances them well, I'm always with in .02 volts across all my 6, 6 cells that are on my charger. (try that in series)
People are afraid of new things, and if you are don't try it and buy more chargers.
I totally agree with statement above, 1 charger, 1c is the safest way.
i do 1 charger, up to 8 batteries and maybe 0.3C. Takes long but I don't care.
In the field I usually don't don't go more then 2 packs as I want speed.

[RaceMechaniX]

This looks like something Clark W Griswold would do..........



I will say no more.

[Brod]

Vasy is correct with parallel charging,any make of bat.any capacity,ALMOST any state of charge works fine hooked up in parallel.
Lots of guys do it,i do it all the time,takes a little longer with the increased capacity.
BUT packs MUST be the same cell count,ie dont parallel for example a 2S with a 3S or a 3S with a 4S.
Series charging is fine too IF both packs are at a similar state of charge and can be differant cell count too.
Always try to test each cell with a standalone balancer in charging in either parallel or series.
It will give one a good idea on the health of individual cells and be able to sort out good packs fron duff ones.
If a newbie though with lipos its probably better to charge each pack individually to save getting confused as to what works and what doesnt.

[RcBum]

No. No problem. If you run them in series, charging in series also works well.

Thanks for that so i can charge them in series no problem to do them that way do i need an adapter to balance them at the same time 2x3s male to one 6s female where could i buy one from these, i,m using hyperion lipos
Cheers

[vasy]

Thanks for that so i can charge them in series no problem to do them that way do i need an adapter to balance them at the same time 2x3s male to one 6s female where could i buy one from these, i,m using hyperion lipos
Cheers

Sorry man, I bought a board for series charging and it was too complicated and risky to so, I got rid of it and deleted a link. I think it was from www.hobbyhot.com
I think board here will work: http://www.progressiverc.com/index.p...1&Itemid=1
But you will need to wire your own power.
It is for sure not as simple or safe or convenient as parallel.

Good luck!

[RcBum]

Sorry man, I bought a board for series charging and it was too complicated and risky to so, I got rid of it and deleted a link. I think it was from www.hobbyhot.com
I think board here will work: http://www.progressiverc.com/index.p...1&Itemid=1
But you will need to wire your own power.
It is for sure not as simple or safe or convenient as parallel.

Good luck!

Thanks