battery help

[LaBond]

I hv a prblm here wis need u guys help.
I connect in series two packs of 3S li-poly battery together n try run it on the Trex using Align Prgmable ESC RCE-25A. Each pack of li-poly is 1800mah 6V. But t could not start. why?

[X34]

What is the max number of cells or max voltage the esc can handle? By connecting the 2 x 3S in series, the nominal voltage is 22.2 or max voltage is 25.2v.

Most esc would not arm if the voltage is below or above the specified range.

[LaBond]

d esc manual says 5.5v - 12v(lithium 2-3cells) and the output current is 20A, max 25A. BEC output is 2A : 2cell li-ion ->4 servos

I used d amp meter 2 measure d 2x 3s, the reading is 11.2v.

[pakkua80]

I hv a prblm here wis need u guys help. I connect in series two packs of 3S li-poly battery together n try run it on the Trex using Align Prgmable ESC RCE-25A. Each pack of li-poly is 1800mah 6V. But t could not start. why?

The problem is that you just connected in PARALLEL and not SERIES. because u mentioned that it's 11.1 V on ur Multimeter.
secondly, there is not lipo pack at 1800Mah 6V ( I suppose it's 11.1 V cos u mention 3S lipo battery)
Did u connect both wire of the same colour together and plug it into the ESC ?
and btw, ur setup in short is called 3s2p(3series2parallel battery) and it will provide 3600Mah and it's a BIG battery for ur TREX.

[Simys]

LaBond, it is good to know a bit of electronic stuff. If not, you might have to spend more money in replacing them as wrong connection on the Lipo cells can do serious damage to your ESC and your receiver.

[X34]

LaBond,

Are your pack in series or parallel? If indeed in series, your lipos are history. Have u charged them before?

[LaBond]

thks guys. my elect engr checked n found that 2 of d cells were gone case. all connected in series.