Charging Multiple 2S Packs (130X) - Help!

[BKozan]

So currently I fly a 130X, and have no real interest in moving up anytime soon to larger Heli's. However, the charger that came with the 130X seems to be destroying batteries lately, and even when it works it takes 45 minutes to do one battery. So I'd like to buy a good charging setup that will grow with me over the next X years. I'm just looking to get the right setup for a hobby flyer, and am not looking to be cheap.

So I am reading good things about the PowerLab 6. But before I buy it, what extra cables, balance boards, parallel boards and USB cables do I actually need? This is where I begin to get extremely confused.

The 130X batteries only have the 3 pin plug, they do not have the large black/red banana plug lead.

So if I bought a PowerLab 6, a CP8S-PAR Balance Board, and a generic 'squid' cable for the 130X, am I ready to hook it up to my car battery and charge 6, 2S packs at the same time? Am I missing something?

I never realised I would have to be an electrical engineer to play with Helis. Geez it's complicated. Thanks in advance for any wisdom.

[Gregor99]

Originally Posted by BKozan

So if I bought a PowerLab 6, a CP8S-PAR Balance Board, and a generic 'squid' cable for the 130X, am I ready to hook it up to my car battery and charge 6, 2S packs at the same time? Am I missing something?

You could do that. But I would (and did) do this instead. Get one of these http://www.progressiverc.com/safe-pa...-umx-130x.html

and one of these

http://www.progressiverc.com/fma-pow...nce-cable.html

Then remove all but the first three wires from the pigtail (second link). Cut off the JST-XH end that goes into the charger, and replace it with the FMA pigtail. There's only three wires to solder and cover.

When charging those smaller packs you can power the charger from your car, or even a larger LiPo.

[BKozan]

Great info, thanks for the reply. I am really keen about using a larger LiPo to run the charger, but have a few questions...

Firstly, which would you recommend? I'd say on an average flying session I'd like to fly 8-10 batteries. On occasion I might hang around and fly 15 batteries if the weather is good and I haven't broken anything.

What would be the daily routing for the 'large' and small LiPos? When I get home and am done flying for the day (let's say 24 hours), do I need to run both the large and small LiPo's through a "Storage" program? Then the next day, use the charger and my car battery to charge the Large LiPo, and then take the lot to the field, and use the large LiPo to charge the 8-10 small ones?

Or perhaps I could simply charge the large LiPo once, and then use it to charge 30+ small LiPo's over the next 3 days (72 hours), before needing to maintain or re-charge the large LiPo?

Thanks again for the help!

[Gregor99]

General rule of thumb for LiPos is to not store them fully charged for any length of time (more than several days).

For the 130x cells, I would charge them the day I fly them. If I don't discharge all cells and I'm sure I'm coming back the next day, I'd leave them charged. If I'm not sure when I'll be coming back, I'll discharge them to storage.

I rarely will charge a pack up to storage level. If the pack is severely discharged (resting voltage below 3.60v-3.67v) I will charge it up to storage. Or if I am putting the packs away for the winter.

For the larger LiPo I'd charge it up on day 1. The see how far it discharges during that first day. Storage voltage is a range, so its not necessary to have it at 3.85v. By day 2, if its not down to ~4v per cell than I might adjust my approach. I would only charge it up to 4.1v per cell and see how that works out.

The other, perhaps far safer option is to use large LifeP04 cell. There are some big ones by Headway. Get 3 in series for 12v. No worries about LiPo safety, storage voltage or over discharge.

[BKozan]

You are a champion Greg, thanks for all the help.

Last question, I swear!

Is it safe to assume that I can line-up the mAh rating of the batteries, and then do simple math?

ie. If I buy a 3S 2200mAh 45C Lipo, I can use that to run the PowerLab 6 and charge approximately 4, 2S 460mAh 35C batteries? (2200 / 460 = 4.7)

[Gregor99]

The mah alone won't line up because of the difference in cell count. Its easier to convert to watt hours. Plus you have to account for efficiency losses in the charger (10%), as well the 20% reserve in the packs. You can only take 80% out of the 2200. But only have to charge the 460mah packs up 80% (unless flew too long)

Here is an example using 80% of the 2200 and nominal voltage of 3.7v per cell.

1.760 x 11.v = 19.536 wHrs.
Take out charger efficiency = 17.582 wHrs

That's what's available to the pack. Now calculate the wHrs for the each 130x pack. I'll use 368 which is 80% of 460mah

.368 x 8 = 2.95 wHrs

Divide the watt hours for each pack by the total available from the 2200 pack. If I did my math correctly that's just under 6 charge cycles before the 2200 is at 20%.

[BKozan]

Greg, thank you so much for all of this information, it is amazingly helpful.

Today I've received all of the items you have listed (PowerLab 6, Safe Parallel Charge Board, and Balance Cable) and I am very excited to get this up and running. But before I plug it all into my car and light the whole lot on fire, can I please request some clarification...

Originally Posted by Gregor99

..remove all but the first three wires from the pigtail (second link). Cut off the JST-XH end that goes into the charger, and replace it with the FMA pigtail. There's only three wires to solder and cover.

So if I plug in the FMA pigtail (8 wires) to the Powerlab, I should only be left with the first 3 wires, from left to right (Black, White, White). Is this correct?

I then cut off one end of the JST-XH (3 wire) form the balance board, and connect the two together. (I assume I line up the black one.)

The reason I am asking, is because both the FMA Pigtail (8 wire) and the Balance Board JST-XH (3 wire) have a black, white and red wire (with the FMA having 6 white wires).

Should I assume that I connect the black and red wires together, and then utilise the first white wire on the pigtail?

Thanks!

[BKozan]

I think Page 63 of this manual answered my question.
http://revolectrix.com/support_docs/item_1380.pdf

Answer: If you leave the PowerLab 6 in FMA mode, then yes - Connect the red and black wires and use the first white wire.

Alternatively - Change the PowerLab 6 into XH/EH wiring mode, and then use the first three wires, making sure to connect the black wires together, with the red wire being "last".

[Gregor99]

You'll need to be in JST-XH wiring mode. Yes, its the first 3 wires from the black wiring moving toward the red wire. On the FMA wire, its black (pin1), white (pin2), white (pin3). The rest of the wires aren't used.

On the balance board its black (pin1) white (pin2), and red (pin3).

Use DVM in resistance mode once you are done to verify the wiring is correct.

[jscklc000]

Originally Posted by Gregor99

You could do that. But I would (and did) do this instead. Get one of these http://www.progressiverc.com/safe-pa...-umx-130x.html

and one of these

http://www.progressiverc.com/fma-pow...nce-cable.html

Then remove all but the first three wires from the pigtail (second link). Cut off the JST-XH end that goes into the charger, and replace it with the FMA pigtail. There's only three wires to solder and cover.

When charging those smaller packs you can power the charger from your car, or even a larger LiPo.

Will this work with my setup http://www.hobbyking.com/hobbyking/s...e_Charger.html and http://lipoconnectionsolutions.com/1...rgers-1247.htm
I just moved up from a NCPX to a MCPX BL and would like to take advantage of the balance charging offered by this charger.