Parallel charging 3x 3s packs with a kink

2 of th epacks are discharged and 1 is fully charged.

Category:

Entertainment

Tags:

• reheli
• 3x3s
• kink

[squarepants1961]

Great video, I only wish I saw this before I hooked up 2 packs of 3S across the board, which blew the pin off my board and the negative pin off the battery pack balance plug. I now connected other packs as you described and works well,

[tahoeskiier]

The problem with this as I have read has nothing to do with the packs blowing up or even getting hot. The full pack will discharge into the lower packs and they will all equal out. No biggy. The problem is the cc/cv factor. The dead batteries are dead and should be started charging at a lower voltage. The charger thinks that they are more full and hits them with a higher volt than they are ready for. Its like fast charging, it works in a pinch but will slowly damage the batteries

[irwinfc]

@mats1401 i bet the 3.5A spike you saw was just momentary. the thing is, the charged pack can only give so much for a short period before it "charges" the discharged pack and level off. what i wouldn't try doing is placing the balance taps in parallel BEFORE connecting the main discharge leads because that stresses the cells individually. THAT is more likely to cause damage to cells with lower SOC.

[irwinfc]

@gi1mo2 electrons do pass between packs with unequal SOC when wired in parallel - tests are not needed to verify that.

[michael100700]

Do the math on that!

Or use an Amp Meter...

and use 2 fully charged and one empty pack (3V/cell) for best effect :-)..

[gi1mo2]

What you should try is let your packs connected without charging them and check each pack after some elapsed times (1, 5, 10, 30 minutes), and see if any current has been transferred between packs. If yes, then DON'T DO THIS. You may not see any sparks, but you will reduce life of your batteries. Also, bad idea to charge on a wooden surface.

[mats1401]

This may work with your packs, but it's evident that the charging current gets too high if you connect a discharged pack with a full one. The current will be the voltage difference divided by the sum of the internal battery resistance plus the cable/connector. I measured between a SLIGHTLY discharged pack (1500mAh, Zippy 20C) and a full one of the same type a current of around 3.5A, which is more than 2C. You don't need hot cables or sparks to over-stress the discharged batteries!

[ggcrna]

What is that board called?

Is it a balancing board? And where did you get it. Did it come w/ your charger?

Is the balance plug from the battery a JST-XH?

Your video is very well done. Nice image, and good info. Thanks for the help.

I am waiting on an Accucell charger & want to charge 2 2s 4000mah lipos @ simultaneously.