Is it normal for a TX battery to loose charge while turned off? After a full overnight slow wall charge, the transmitter indicates it has 11.1v. but I was not able to go to the airdfield. After 4 hours I turn it on and it now indicates 10.6v without using it. Is this normal? What should I do? Thanks for the imput.

Hi!
Yes! Voltage will drop over time.
That's why you should allways charge (wall/slowcharger )before you go flying regardless of when you last charged.

the answer you have just gotten is correct

I went to Radio Shack and bought 8 2800 mah nimh aa size cells and made my own pack with them, I already had a MRC Super Brain 959 to charge it, that charger sells at most hobbystores for about 50 bucks.The radio now holds its charge many many times longer than it did with the stock 600 mah nicd pack.It cost me about 32 dollars to build the pack, It was worth every penny.

So it is normal, no worriies! Thanks for the answers!

IMO, NOT normal. It shouldn't drop 0.5 volts in 4 hours of non-use. To be on the safe side, I'd check each individual cell. If you find one significantly lower than the others, replace it.

Dr.1

10.6 MIGHT be a bit low but 10.8 is very common. I charge overnight and don't unplug until I'm rolling toward the field. Saving every available electron. Wouldn't hurt to cycle your pack a couple of times and check again.

My radio was at 10.8v when I went to the field today, it was 4 days ago that I charged it up.

Another 0.2 drop across 8 cells = .025 per cell if even across all cells. Not too bad. You can check to see if it's all in one cell though.

NiCads self discharge 1 or 2% per day just sitting around. The AA size cells are 1.2V, and eight of them are 9.6 volts. As your TX meter shows, you've actually overcharged them (which is normal as they get a 14V "kick" from the wall wart. That overage goes away much faster than the plateau voltage will. My 9C "normally" reads 10.6v whan I get to the field, and I keep all my Tx & Rx on a timed charger that hits them with 15 minutes of charge every day to keep them topped off. What is scarry is that a 9.4v cell is about done and shouldn't be flown, but a 9.6v cell may have 80% of it's flight time left. The voltage alone doesn't tell you much.

Invest in a digital read-out charger/discharger (i.e. the Hobbico Accu-Cycle) and an ESV (expanded scale voltmeter). They put a load on a battery and tell you how it is doing.

I'd guess 3/4 of "accidents" where pilots claime to have been "shot down" are because of battery problems. They wear out and require maintenance like anything else.

G'day Mate,
The nominal voltage for a TX is 9.6 Volts, 8x1.2volts. it will always be higher after a charge, & it will loose that higher voltage, in time.
If it drops below 9.6Volts, before you use it for any length of time, then I would be worried, otherwise it is OK.
The cells are not considered flat until they reach 1.1Volts per cell, or 8.8Volts, & most computer TX's will alarm at 9.0Volts, keep an eye on it, but enjoy your flying, & don't be too preoccupied with TX Voltage.