Parallel Charging Questions
 

Hi Everyone - I am pondering upgrading to a charger with higher charge/discharge rates. I have been doing some research and have a couple questions.

1 Can you discharge multiple lipos at the same time using a parallel board?

2. Can you put multiple lipos into storage using a parallel board?

Thanks!

As long as they are the same series cell count yes, or same nominal voltage if you prefer. All 2S together for example, or all 4S. But not a 2S and 4S at the same time.

Advisable to check the individual cells of each pack for reasonable balance occasionally when doing a lot of parallel connections. Good practice for all use of course.

I wouldn't discharge on a parallel board. The charger will always see the highest voltage cell, so you could over-discharge one pack.

As long as the balancer is connected and working it's not an issue. With a parallel connection the voltages can't be different, the direct connection between paralleled cells prevents any difference. Or at the very least quickly equalizes any difference, like when first hooking the packs up.

Even without a balancer connection one pack can't go low either, but a cell within a pack could.

How often should I be balance charging my lipos? Usually i balance charge them the night before going to the track. Then at the track i just fast charge them at 1C.

Between my sons and I we have 4 cars that take shorties, so we have various 2s capcities (3500 to 4700) for stock and 4wd buggy. We have somewhere around 9 batteries total.

My plan is to get an iCharger 406 Duo. I was hoping to be able to balance parallel charge them on both channels (4 batteries per side charging at 20amps per side) the night before. Then I could charge in 3 battery batches at the track.

Another reason is anytime i had a fully charged battery at the end of race/practice it takes so long to get into storage because the discharge rate is 1amp. I am hoping the duo will speed this up as well.

Ideally, every time you charge. The new charger will significantly improve the ability to do this as you would be able to charge at more than a 1C rate as well as discharge faster. Of course though, cant (shouldn't) balance multiple packs while parallel charging without some special balance board equipment and also making sure lipos are of similar size and age.

dst.. you can parallel charge your battery's they way you ask.. but I really have No faith in the parallel boards I have seen. they all are failure prone . and when ur putting 20 amps into a 4000 mah lipo that could result in bad things..

as 4 discharging no.. I suggest you get a 15/20/30 amp reactor discharger ..http://www.integy.com/st_prod.html?p...6#.VZ7iObWR-1s

one of these will discharge a battery in less than 10 minutes.. I have several and a Tekin 12amp/24 amp discharger... There was a post I think by howardcano on a reactor mode to adjutst internal pot to 7.8volts.. also get a lipo buzzer to monitor as it dis-chargers.http://www.rctech.net/forum/radio-el...r-2s-lipo.html

so i would use the reactor as a stand alone discharger or in conjunction with the an icharger?

I am somewhat confused on the ability to balance batteries with parallel charging. It sounds like its possible, but i would need to build my own parallel board because of quality issues...

I was looking at these for parallel charging...
http://www.progressiverc.com/t-plug-...rge-board.html

You need parallel connectors or a parallel board for balancing as well. The safest is the FMA board, just make sure to include the right balance cable for the charger.

Kind of expensive, but probably worth it for the peace of mind. Thanks for the link!

If I'm not mistaken the Buddy RC/EP Buddy V3 ParaBoards are fully fuse protected as well.

Here is the one I have. I dont walk away either when I am charging on this. I hang around and watch it. Im charging on balance at nearly 2C. Four 3800mah packs. I have gone up to six batteries. It works great when you have alot of the same batteries and need to charge them up quickly. I wish we had these when I would run Emaxx's.
http://i1164.photobucket.com/albums/...psxcyquz6w.jpg
http://i1164.photobucket.com/albums/...ps87azx6gl.jpg

Jimmy, capacities add with a parallel hookup. Four 3800mAh packs are essentially a 15,200mAh pack. 7.2A is less than 0.5C. 2C would require over 30 amps from the charger. Crank it up!

A reminder to always be aware of charging, when many mishaps occur, is always good. :nod:

Thanks for the math Dave, now I gotta get a bigger charger... sigh!!

Sorry! :)