RCU Forums - Mayday!

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I was wanting to fly this morning, but accidently left my transmitter on all night. I have it on charge right now. The batteries were almost completely dead. How long will it take on a standard charger to recharge?

No. If the batteries are nearly completely drained, it will take at least 16 hours to fully recharge with a C10 charger. (The one that came with the radio.) You'd be better off leaving it for 24 hours in my opinion.

The C10 charge rate on our wallwart chargers is usually about 50 mA. Most transmitter packs are 600 mAH packs. So theoretically, 600 mA's divided by 50 mA's per hour = 12 hours. But with the losses due to the cells heating, or for inconsistencies in chargers, the minimum recommended charge time is generally 16 hours. ;)
Dennis-

The charger will say what the charge rate is on it. Just divide the capacity of the batteries by the charge rate on the charger.

Thanks for the info. This part of the hobby definately needs to join the modern age :)

You just need to get a better charger. Those wall Warts that come with the radio are fine for every day use, but a good charger can really be an asset at times.

buy a fast charger then when you're in a hurry you can be charged in about 15 minutes.;)

Caution with fast chargers... you can cause NiCds to explode if they get too hot. The NiCds n a TX are not designed to handle the 15 min charge rate. A 1 hr rate is safer. (and don't neglect to get the peak detecting charger that turns itself off. Timer/resistor chargers destroy batteries.)

One time letting the NiCds go flat like that... probably not a big problem. But do it a few times and you can ruin the battery. NiCds don't like being drained below 1.1 v per cell.

Another note about fast chargers... remove the battery from the TX while charging. It alows better airflow around the battery keeping it cooler. It avoids any diode in the TX without doing a TX modification. (peak detect and a diode in the charge circuit = no peak detect!)

Quote:

ORIGINAL: FHHuber

Caution with fast chargers... you can cause NiCds to explode if they get too hot. The NiCds n a TX are not designed to handle the 15 min charge rate. A 1 hr rate is safer. (and don't neglect to get the peak detecting charger that turns itself off. Timer/resistor chargers destroy batteries.)

One time letting the NiCds go flat like that... probably not a big problem. But do it a few times and you can ruin the battery. NiCds don't like being drained below 1.1 v per cell.

Another note about fast chargers... remove the battery from the TX while charging. It alows better airflow around the battery keeping it cooler. It avoids any diode in the TX without doing a TX modification. (peak detect and a diode in the charge circuit = no peak detect!)

I agree with everything you've said here except for removing the battery. That's what I was doing on my Futaba tx until I bypassed the diode. I was concerned with how the plug is in there and how difficult it was to remove. Because I was doing a lot of flying, I was charging 10 or more times a week. I was very concerned about a wire breaking or worse - mostly breaking and then giving up in the middle of a flight. If they made the tx with a better system to plug the battery in then I would take it out, but as it is, I think it's too much strain to be repeatedly putting on the connection. Just my opinion.

- Paul

It can be a problem removing the TX battery on some radios... but there is a fix. (and its easy) Futaba Conquest and a couple of others use a strange plug that you have to remove screws from the radio, pull the back cover and its a real mess to unplug the battery.

Get a short aileron extension cable. Clip in half.

Cut the battery's wire about 1 inch from the battery.

Solder in the aileron extension cable.

You now have a plug that is reliable and easy to get at.

If the radio doesn't have the strange plug... you just take the short aileron extension and leave that plugged into the radio... the battery will have a plug that is compatible with it already. :D

Quote:

ORIGINAL: FHHuber

It can be a problem removing the TX battery on some radios... but there is a fix. (and its easy) Futaba Conquest and a couple of others use a strange plug that you have to remove screws from the radio, pull the back cover and its a real mess to unplug the battery.

Get a short aileron extension cable. Clip in half.

Cut the battery's wire about 1 inch from the battery.

Solder in the aileron extension cable.

You now have a plug that is reliable and easy to get at.

If the radio doesn't have the strange plug... you just take the short aileron extension and leave that plugged into the radio... the battery will have a plug that is compatible with it already. :D

Good tip. :) I have an 8UHP - one that has a battery that is directly accessible. The Futaba site says they make high-end radios with batteries easy to get at because if you own one, you must know what you're doing. But if you're not advanced enough to own a high-end radio, then you don't know enough to figure out how to unplug a battery so they bolt it in. Craziness. :)

That's a real complaint of mine about the Futaba 6XAS. It has a strange plug that actually plugs into a connector on the circuit board, so you have to unscrew the transmitter case and remove the back to get to it. Then it doesn't match anything else, so....

Good advice FHHuber. I'd planned on it, just haven't done it yet.
Dennis-

You can alter the BATTERY without voiding the radio warrantee. (just don't get the polarity reversed.[:-] )

You bypass the Diode... you can void the warrantee.