Parallel Charging for a Newbie

[ekaser]

I have a Racers Edge SureCharge 2010 Pro AC/DC balance charger. It has a 9900 mah capacity and an 8 amp max charge. Can I use a parallel charging board and charge two 2s 5300 mah lipos at the same time? Can I charge two 2s 5300 lipos and two 2s 5000 mah lipos (total of 4) at the same time? Would this be of benefit or should I get a more powerful charger?

Thanks, Ed

[Chilli]

I looked at the specs for your charger and couldnt find an output power (in watts) which makes me think h'mmm. . You can charge all the packs you want in parallel but if the charger has a low power output, It's going to take a long time to charge your packs. And I think that might be case for your charger. The specs says it can charge a pack up to 8 amps. But that's probably only a 1S or 2S pack. It' may only be able to do a single 4S pack at 3 amps which could take well over an hour. And four 2S packs...forget about it.

Now as far as parallel charging. I saw this video on youtube of a guy trying to sell a parallel adapter. He plugs in six different sized 3S packs into a bundle of wires and casually mention all the packs have to be at the same state of charge. I couldnt believe it. I will never ever parallel charge packs. Why? For safety's sake each individual cell needs to be monitored. You cannot do that when parallel charging. I would guess the charger see's the average voltage of all the cells that are paralleled up. All it would take is one cell going bad and you could create an overcharge situation that could lead to a fire.

IMO- The only safe way to charge multiple packs is series charging. You plug the positive wire from one pack to the negative of the second and plug both taps to a series adapter. Now the charger will see the two 2s packs as one 4s packs and monitor the voltages of all the individual cells. You should only do this with identical packs that have been run together. The only down side to this is it's much harder to find series adapters for certain chargers. Something you may want to take into consideration if you decide to buy another charger. I had to make you own.

So thats my take on charging multiple 2S packs together. I'm sure someone will chime in if I'm leading you astray or passed bogus info. As far as whether or not your current charger meets your needs? It all depends on how deep you get into this hobby and how long your willing to wait to charge packs. Hope this helps!

[785boats]

Ed.
I would only parallel charge two packs at a time with that charger.
With a max output of 8A it will only be putting 4A into each pack. With 4 packs, each one would only be getting about 2A so it would take a long time to charge them.
I parallel charge all the time.
The only thing that you MUST!!! do, is make sure that you connect the main power leads together in parallel BEFORE you connect the balance leads in parallel.
Once the power leads are connected, any out of balance voltage flows between the packs & there can be a considerable current flow for a short time.

Nautiboyz.
The packs don't have to be at exactly the same voltage but they must be the same number of cells. Maybe that's what the guy in the video meant about the same voltage. You can't parallel charge a 3s & a 4s pack or a 2s & a 5s pack.

All cells will receive the same voltage & capacity when charged in parallel.
If there is a suspect cell in one pack & it won't charge up over,say, 4.05V then the other cell connected to it through the balance lead will only charge up to the same level. It will not overcharge the good cell.

If you've got some spare time, have a read through this. Interesting stuff.

http://www.rcgroups.com/forums/showthread.php?t=932319&highlight=parallel+charging

Cheers.
Paul.

[ekaser]

Thanks fellows for the guidance. I am thinking that getting another charger in addition to the one I have will help. I have found several to consider on this forum.

Thanks, Ed

[epsonjackson]

thank you for this, and i thought that parallel charging is bad

[Chilli]

Good stuff and informative though I still think charging in series is safer. The reason being to monitor individual cells. I've only had two packs puff on me. Both times I knew they were going bad in advance because the cells had a hard time balancing. I marked them and kept a very close eye on them. As soon as they showed signs of puffing on me, I disposed of them properly. When charging packs I'm constantly checking the packs individual cell voltages. Have fun and be safe.

[ekaser]

Nautiboyz,

If I charge in a series how do I monitor individuals cells. Check out my charger in the original post.

Thanks, Ed