Using balance leads for power?

[FE Wannabe]

I am running 2 6400mah 3S lipos in series in my 32" mono and I have a 12V fan on my ESC. I was wondering if it would be OK to draw 11.1V power for the fan from the balance connectors of one of the 3S lipos? It is only a 40mm fan so the amp draw should be minimal. Right now I have 6V power being supplied by my BEC to power the fan, but it is spinning the fan somewhat slowly. Let me know what you think.
Thanks,
Brad

[Boatman]

I would go this route or something similar. Just for ease and peace of mind. You can have your 12V and be worth the weight of only less than 8oz.

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXGBM5&P=7

[ReddyWatts]

FE Wannebe it will work fine to use the taps to run a fan, but it could get your packs out of balance if accidently left on. My 40 mm fan uses about 60 milliamps. (I would double check that with the brand you are using.) Use a connector made for your lipo taps connector, so you dont accidently short the cells.

[FE Wannabe]

Thanks Guys

Thanks for the replys. Reddy,
I will verify the amp draw but I think it is similar to what you posted for yours.
I will use the correct female adapter for the fan's power lead just to make sure there are no shorts.
Thanks again.
Brad

[AntronX]

Tapping power from your balance leads in not a good idea, regardless of how little current you are pulling from it. Here is a better idea, use this linear voltage regulator: http://mouser.com/Search/ProductDeta...1Xmn60XA%3d%3d You can also find there at RadioShack, or any local electronic parts store.

It only costs 26 cents, will take up to 35 Volts input and regulate it down to 12 volts for your fan. It will get hot while operating, so attach it to a little piece of aluminum if you can. But if you just power a little fan from it, it should be ok without cooling.

[ReddyWatts]

Why is it not a good idea?

[sjslhill]

yes, if you are using energy from all 3 cells, I can't see how that would get them out of balance. Leaving it on however could ruin the pack. Who makes a 6400mah anyway?

[ReddyWatts]

and even if you accidently left it on for 1 hour it would only get it 1% out of balance from the fully charged mah rating. 100 hours to totally discharge it.

[Bill-SOCAL]

Boatman, I'm curious, where did you get your avatar??

[FE Wannabe]

yes, if you are using energy from all 3 cells, I can't see how that would get them out of balance. Leaving it on however could ruin the pack. Who makes a 6400mah anyway?

The battery is made by AirPower Models. It is a 3S2P 20C 6400mah battery. It is actually 2ea 3S 3200 battery's connected end to end.
It makes for a long thin battery that fits nicely alongside my rails in my mono.

[sjslhill]

Nice.....

[Boatman]

Boatman, I'm curious, where did you get your avatar??

I, uh was just borrowing it. I will put it back when Im done I swear.

[Bill-SOCAL]

Just curious. It looked awfully familiar!!

Enjoy!

[Boatman]

Hey Bill, It's back in its proper place. Such whiny little motor heads