Flyboy76

My Feedback: (14)

Hello all i have been in the hobby for a couple of years now and still have all my origional batterys for my recievers and for my TX. What is the best way to make sure they keep taking a good charge. I have been noticing that my TX battery def. does not last as long as it use to and my reciever batteries i am paranoid about so i charge them everytime i fly. I usually only get out to fly for about an hour or two most of the times. Should i be running the reciever batteries right dead and then charging them up or is there something else i should do.

Flyboy76

spiral_72

If it's a Nicad like mine:

I can discharge the Rx 600mA battery completely through my Hobbico tester. It's a voltmeter that simulated the load of the Rx system. The Tx, you can just leave on.
I used to discharge it through an 12V automotive bulb or a large 5W resistor, something around 20 ohm to give me about a 250mA dicharge rate.
Once completely discharged, make sure you charge it again completely and uninterrupted. This's called cycling the battery. You can also buy charges to do the same thing. This every once in awhile erases or reduces the "memory" of the battery.


I don't like to discharge the Rx battery in the plane, because once the battery gets below a certain point, the electronics go nuts and jack the servos hard to one side.

I don't know about the Li-polymer stuff.

Rodney

The only way to know for sure that your batteries are still reliable is to run a controlled cycle. That means charging for 16 hours at 0.1C (you do not have to discharge first) then discharging at a controlled rate of not greater than .25C (preferably at .2C) down to 0.9 volts/cell. If the resulting value is at least 80% of the rated battery capacity, you are relatively safe to continue using them. If the batteries have been dormant for an extended period of time, you may have to repeat this slow charge/discharge procedure two or three times to bring the batteries up to full capacity. Check out www.rcbatteryclinic.com or www.batteryuniversity.com/parttwo-33htm and/or http://members.aol.com/davthacker/balancecharging.htm for some good reliable info on the care of your batteries.

Flyboy76

My Feedback: (14)

once you start talking about ohm's and discharge rates my eyes start to glaze over as i know nothing about them. I think it is time to do some reading on this topic. Thanks for the replies and links

Flyboy76

BarracudaHockey

My Feedback: (11)

You dont need/want to cycle lipo.

As for the nicads, I'd get a cycler, its a cheap investment compared to tearing up a plane or two by failed batteries. I like the Accucycle Elite but there's a lot of good ones out there, and by now there are probably some that are even more flexable.

Cycle the battery and if after a few tries the capacity is 80 percent or below of the rated capacity, discard the battery properly and then replace it.

The nice thing about most of the current cycler/chargers is you can input the cell count and milliamps and it will do the rest of the math for you with the default settings.