Flightpower 2S balance lead confusion

[barney]

Have a flightpower 2S RX battery here that I pulled the Balance plug off a while back. Now wanting to replace with a JST but notice the Flightpower uses 4 cables from a 2S

Needing a very simple pic or diagram...LOL

does this mean one lead is redundant since my other 2S batteries only have 3 leads

Ta Brian

[waveydavey]

You'll probably find the last red or coloured one in the line is just tucked in the pack Brian. Only 3 are being used

[bolders]

I guess it is either redundant or connected in parrallel with another of the balance leads as you would only have 3 terminals on the battery cells .

I assume you are running JST connectors on your other packs. If so I would suggest the following.

Take a battery with a JST fitted and conect a voltmeter probe to the negative battery terminal. Probe each of the the pins (1 at a time) on the JST connector and measure the voltage then note down the position in the JST socket connection and voltage recorded.

Then do the same to your flight power pack and note the voltages for each of the balance leads. Then connect this battery to a new JST connector using the sequence you determined for a pack with an existing JST connection.

If you find two balance leads with the same voltage then those two leads are connected together.

Or you may find two leads with 0 volts - in this case one will be connected to the negative battery connection. The other cable may also be connected to the negative battery terminal or floating.
To check switch your meter to measure ohms and recheck these two connections. relative to the negative battery terminal. If a cable reads approx. 0 ohms it is connected to teh battery neg, if it reads a high resistance or over-range then it is not connected to anything.
NOTE only measure the resistance of cables that measure 0 volts between them

[gazelle341]

I have an old Flightpower 2s which I have just cut open.
I can confirm that the last Red wire is spare and is tucked inside the cover but not connected as suspected by waveydavey.

The Black wire is connected to the battery negative with the main Black wire.
One Red is connected to the junction between the two cells and the third Red to the positive with the main Red cable.
As Bolders suggested you can use a meter to measure which Red is which.

Also the Red to the junction between the two cells runs down one side of the pack to the opposite end to the connections, and you may be able to see which wire this is.

Cheers
Mick

[barney]

Wavey's the man, before I reached for the voltmeter (thanks bolders) I gently pulled each in turn and yippee one was just tucked into the pack

thanks guys Brian..Oh and Mick your fingers werequicker than my reply..LOl