RC India

RC Equipments => Batteries and Chargers => Topic started by: gauravag on October 10, 2010, 07:27:35 PM



Title: A123 battery pack having problems
Post by: gauravag on October 10, 2010, 07:27:35 PM
Guys,
Ok Looks like i have started having problems with my A123 pack. When I had this tail kicking issue, i came back and charged my battery it took in 360mah which is an OK amount for a little more than one tank of sport flying i did today.

After full charging, I discharged, and it gave only 550mah !!! Whoa !

The battery has had around 50 cycles so far. Its the one that Hk sells, and A123 racing is the original battery company that makes these cells.

Any ideas to revive this back ? Or do i assume the pack has gone ?

Thanks
Gaurav


Title: Re: A123 battery pack having problems
Post by: anwar on October 10, 2010, 09:55:49 PM
Discharged via the charger itself ?  What is the capacity of the pack ?

Can you try charging it one more time ?  It is NOT unusual for batteries to last ONLY 50 cycles !


Title: Re: A123 battery pack having problems
Post by: gauravag on October 10, 2010, 10:15:50 PM
Yes, i discharged using the charger. Capacity of the pack is 2200mah.

Cycled it thrice. Gives around 500 mah only.

The glitches with the rudder happened twice today - once when i was pulling out of the loop, and the other during the stall turn, Possible that due to loading of collective, the voltage might have dropped causing the gyro to reset itself  ?


Title: Re: A123 battery pack having problems
Post by: anwar on October 10, 2010, 10:27:22 PM
Check your cyclic pitch ranges, it could be that you are causing one of the servos to bind, causing its draw to go up, and pull the voltage down on an already low charge battery.



Title: Re: A123 battery pack having problems
Post by: gauravag on October 10, 2010, 10:29:04 PM
Checked that earlier with a ampere-meter. No binding of collective/cyclic or rudder servos.

Any recommendations on which A123 battery to go in for ? Hyperion / Fromeco ?


Title: Re: A123 battery pack having problems
Post by: anwar on October 10, 2010, 10:53:57 PM
When you are having not enough receiver power, all bets are off.  Glad that nothing bad happened.  Usually the issues show up when the load is high, hence the suggestion of looking for binding.

Both the brands you mentioned are well respected.  Fromeco has very high regard for their regulators in heli circles.  Pretty much everyone I know are in the "lipo + regulator" camp, so can't really comment much on A123 sources.


Title: Re: A123 battery pack having problems
Post by: roopeshkrishna on October 15, 2010, 07:43:34 PM
Hai friend..you can simply overcome this problem by adding a transistorised current controller.its all cheap, and can make without any PCB.and weighs around 50 Mgs.