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        Help! Mini super cub battery or charger problem

#1 Cotton17 Aug 30, 2009 06:30 PM

Mini super cub battery or charger problem
 
Hi I'm new to the forums and am just wanting some help with a problem I have with my mini super cub. After flying it last I left the battery connected to the plane , I then went to charge the battery and the charger won't charge it. When you connect the battery to the charger it is supposed to flash red meaning it is charging, then stay red when it is finished, but instead it blinks 3 times then stops. So I don't know if it is the battery or the charger. I did read in the manual that you are supposed to disconnect the battery after using the plane, would leaving the battery connected damage it? So is it the charger or the battery? Thank you for any responses

#2 Challenger 413 Aug 30, 2009 06:37 PM

Yes, leaving the battery connected to the plane(or to the ESC) will cause it to be drained. What type of battery is it?

Challenger413

#3 Cotton17 Aug 30, 2009 06:47 PM

It's a 300mah lipo

#4 Challenger 413 Aug 30, 2009 07:09 PM

Verify what the voltage is with a D/C voltmeter.

Challenger413

#5 Cotton17 Aug 30, 2009 07:17 PM

The voltage of what the battery or the charger? The battery is 7.4v and on the charger it says input-240v AC. Output-12v DC

#6 Challenger 413 Aug 30, 2009 07:29 PM

Use a D/C voltmeter and measure the pack voltage, I am thinking the voltage is too low for the charger...

Challenger413

#7 Cotton17 Aug 30, 2009 07:34 PM

I don't have a voltmeter to check it so would it be best to just buy a new battery or is it the charger not having enough volts to charge the battery?

#8 ebill3 Aug 30, 2009 08:33 PM

You really do need to get a voltmeter. It sure sounds like the pack was discharged to the point that the charger will not recognize it.

Take a look at this thread. In that case it was a 3 cell LiPo, but the same procedures apply to your 2 cell.

Bill

#9 Cotton17 Aug 31, 2009 05:15 AM

Thanks for the help I'll see if I no anyone who has a voltmeter I could use and if not I'll go to my lhs for help

#10 Cotton17 Aug 31, 2009 04:04 PM

I got hold of a voltmeter of a friend and measured the battery and it read about 4.5v when on the battery it says 7.4v is this good or bad?

#11 ebill3 Aug 31, 2009 05:01 PM

Quote:

Originally Posted by Cotton17
I got hold of a voltmeter of a friend and measured the battery and it read about 4.5v when on the battery it says 7.4v is this good or bad?

Bad.

After use and a short rest period, ought to be 7.6 volts or so.

OK, the charger will not charge the pack until it sees some minimum voltage - normally about 3 volts per cell. If you can get the battery back up to about 6 volts or so, it will probably charge.

Bill

#12 Razor_Racer Aug 31, 2009 05:06 PM

My CX2 lipo experienced the same thing. I used a 6 cell pack from a rc car, and very very quickly applied short bursts to the lipo to get it to an acceptable voltage for the charger to charge. I did notice a large decrease in power though, and there is risk of an exploding lipo :eek:

#13 Cotton17 Aug 31, 2009 05:36 PM

How do I charge it up to about 6volts? as when I connect the battery to the charger it won't charge

#14 Xpress.. Aug 31, 2009 05:49 PM

You use an NiMH charger and plug it in for about 2 minutes, at the appropriate charge level. Then take it off, and plug it into the charger. NO guarantees it will come back to life, but it's worth a shot.

Also, a fully charged lipo will be 4.20 volts per cell, or in this case 8.4 volts ;)

#15 ebill3 Aug 31, 2009 05:50 PM

Quote:

Originally Posted by Cotton17
How do I charge it up to about 6volts? as when I connect the battery to the charger it won't charge

See post #8.


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