bryris

Let me see if i have this right:

When I test my 4 cell rx battery with my new Hobbico tester - it indicates 5.10 volts. This is higher than 4.8, so the charger gives me an OK indication. Does this mean the battery is as good as fully charged? Can I go out and get a day's worth of flying (3-5 flights) on this battery?


When I test my 9.6V transmitter battery, it is showing 10.5 volts and an OK indication. Does this mean that the transmitter is ready to go as well? (Also, my radio is a Futaba 7CAP, it apparantly has that diode in it which prevents the voltage from being tested at the charge jack. I must either remove the battery to test it or just read the volt indication on the radio screen - if the screen voltage drops below 9.6V, should I land and call it a day?)

The instructions say that when the indication drops below either 4.8 or 9.6V, then the battery is not ready to use. It must be charged first. Does this mean that with 3-5 flights of use on both batterys, the charge will likely stay higher than the 4.8, 9.6v threshold?

I am trying to make sense of the indications that I see. I don't want to lose an airplane over a dead battery.

Thanks.

nicadflyer

Sounds good to me.

The Ghost

Nicads have a nominal voltage of 1.2Vcc with a minamal voltage of 1.1Vcc The voltage you are seeing would indicate a full charge. You should get 5 filghts out of your pack, provided there are no binding servos, linkages ect. You fly the model and check voltages after the filght, after a few flights you will soon learn how many flights you should be able to get (mins flight time) out of a charge. The secret is to keep a check on your flight pak after each flight.

Cheers.

bryris

So what voltages would indicate a need to stop flying a charge the bat? On both rx and tx.

JaredM25

My Feedback: (26)

Well for a 4.8 battery i, and this is only me, would stop at 4.8..If i'm using it in a plane with high-drawing servos i usually stop at 5.0V, because if you are in a maneuvor that puts load on all the servos, if your battery is at 4.8, it will well go below the flying limit, maybe causing loss of control of the plane, temporarily. On a Tranny pack, 9.6V I usually stop at about 9.6, or sometimes ill go down to 9.5, 9.4, before charging...THis is according to the Radio screen voltmeter, not sure how accurate it is, but thats what i went down to on my 9CAP, and the 7 channel is basically a cheaper, less capable than the 9CAP...that what it seems like to me though..
HOpe this helps...
Jared

Stick Jammer

A fully charged 4-cell pack should read around 5.3 volts. Personally, I recharge when the voltage drops below 5v when checked with an ESV. Some like to fly all the way down to 4.8v but I don't see the need to push it that far. You must check the voltage with a load. A fully charged Tx pack should be 10.6v and should be recharged when it gets below 9.6v.

DBCherry

My Feedback: (4)

Agree with StickJammer. I have a quick peak field charger and always charge my receiver packs if they get to 5.0 volts, although you're "safe" to 4.8.

The number of flights you get will vary; with how much you manuever, how much your servos draw, and how long each flight lasts. I would NEVER fly more than 3 without checking voltage, and usually check with an ESV between each flight.

The transmitter will discharge quite a bit more slowly than the receiver pack, and I sledom have to recharge it at the field, even when bringing 2 or 3 planes to the field at a time. (At least 8 or 10 flights with capacity left.)
Dennis-

Rodney

What has been said above assumes that the ESV being used is loaded. This is not always the case, if the ESV is not loaded the voltage readings can be very missleading by giving you to high a reading.

DBCherry

My Feedback: (4)

Very true Rodney.

I'd also mention that it's best to take a reading immediately after landing, because if you wait a few minutes the battery cells can "recover" a bit and you can also get a slightly higher reading than actual.
Dennis-