I bought a Futaba 6XAS from a guy at the local club. The gentleman tells me that the radio works flawelessly-Ok no problem.

I bring the radio home and I turn it on to let it draincompletely-- and it does--so low that the power light is baraely a glimmer adn the radio wont even beep when you turn it on . . .

When I plug the radio in and let it charge for 15 hrs- per the instructions--I turn it on and it shows 11.1 volts. That was two days ago--no when I turn it on after no use at all, it reads 10.8 volts-- This may sound stupid, but is that normal ??

Please respond--

Also is there an easy way to discharge tx and rx batteries without a special piece of equipment ?!?!?

Thanks Tbird

Yes that is normal. Nicds tend to loose their inital charge very fast. Remember your transmitter pask is rated for 9.6V so 10.8 is still very good. TO discharge my batteries I leave my transmitter on until it beeps (I have the same one as you) and for my plane batteries I connect a volt meter to them to drain them.

Chris

Nicad batteries will self disharge. In the first day this can be as much as 10%. Your voltage drop is quite normal. Just make sure that you charge your batteries before you fly!

The voltage will peak right after a charge and will drop down in the 10 volt rantge quickly. Not to be concerned. It is normal. Do not completely discharge the batteries though. Better to get them down to 1.1 volt each or 8.8 volts or so. Then recharge. I don't worry about cycle them too much, usually charge them up and then put them on a timer.

The 11.1 volts you saw was the voltage right after you took the batteries off charge. This is probably close to peak for your pack. All nicads will discharge slightly each day given no use and your .3 drop the next day in indicative of that. This tells me that you probably have a good pack in that transmitter. You need to read all you can on batteries, cycling and charging. It is really way too big a subject and I'm sure if you punch in "batteries" that you can get links to all sorts of thread telling you the great secrets of nicad batteries. With the new Li-Po cells coming out plus other new types of batteries make certain you get information on the types of cells you have. Futaba puts NiCads (nickel cadnium) cells in their stock packs. Other types of cells are Nickel Metal Hydride (NiMH) and the newest Li-PO (Lithium Polymer). This is an area where you just have to do the reading and if you have a question AFTER reading, then ask something specifically.

The nice thing about these forums is all you have to do is ask.....

Deadstik [8D]

Yes that is fairly normal.

The NiCd is an interresting beast. It has an S-curve voltage characteristic. Early n discharge the voltage drops VERY fast, then it levels out for most of the useable charge, then it starts to drop faster and faster. ( a VERY lazy S)

Peak is normally close to 11.0 for an 8-cell pack. You are right in there. The drop of 0.3 v over a few days is normal... the voltage will be about 10.5 to 10.6 at 1 week. The radio will function fine until the pack reads at 9.4, then things can start to go wrong. 9.6 is normally considered minimum to fly. (the rated voltage of the battery pack!)

Going below 9.4 and still flying is VERY dangerous. the voltage drop from there can hit flatline (no useful power) in just a couple of minutes.

***
The reciever pack will have the same type voltage curve... just ranging from 5.6v (I've seen 6.0 once...on an overcharged pack straight off a quickcharger. That was one HOT battery[X(]) down to 4.6 as the absolute minimum you want to see. Again.. the label rated 4.8 v is considered time to recharge.

***

A Nicd has 2 major enemies... lack of use, and heat.

If you don't periodically discharge and recharge (flying counts ) the battery can go bad in about 3 to 6 months. (sometimes they will be OK at 1 year... but that is rare.)

Anything that heats a NiCd above 120 deg F is a problem. A hot NiCd tends to outgass... which will create crystals on the outside of the cells. These crystals are corrosive and toxic. The crystals will desroy your batterie's wire lead, and can destroy the switch harnes (and occasionally the reciever.) Overcharging heats a NiCd quickly.

Overheated Nicds can explode. If you see any sign of bulging of a cell on a fast charger... get clear as fast as possible... its going to pop. You MIGHT save it from exploding by unplugging it... but you would be risking being in the area where fragments and acid will be spewed out. Let it pop. (then you have a hazardous material cleanup issue.... best left to the local fire dept.)

I dont think that I have ever been intereted in anything, Hobbie or otherwise ,with as many helpfulpeople as I have found in this sport. From the field to the forums, everyone is really eager and informitive. Thank You

Tbird

The 6exa is a awesome beginner computer radio. You will have it for a long time. Good choice for a first radio!

Just remember to leave your TX antenna all the way up if you're going to leave it on to drain the battery pack... I understand it's hard on the TX circuitry to leave it on for extended periods with the antenna down.

Real good advice here. I would also emphasize NOT draining your NiCD packs. If you're of the assumption that the packs will develop a "memory", forget it it's a myth.

When NiCD packs were first developed they were used in lab equipment which discharged the packs to an exact level each time. With long term use there was some evidence of memory, but with our use, no way it's an issue.

If you don't use your packs for a month, then just turn on the Transmitter and Receiver and move the controls for 10 or 15 minutes, then charge them for about 12 hours. They'll be fine. Fully cycling them once a month on a battery cycler will keep them at peak performance, so once you get some money ahead, having a cycler/peak charger is great.

FYI, I didn't cycle my packs for the first 3 or 4 years I was involved in RC, and those packs were still over 90% capacity when I bought my first cycler.
Dennis-

I finally bought a cycler in December... after nearly 30 years dealing with R/C. Without ever using a cycler I had one set of NiCds last 10 years. I simply made sure they got used and charged at least once a month.

More normal... the NiCds will last about 3 to 4 years. Some people trash them at 2 years without even testing to see if they are still good.

I just use an ESV after each flight... and if the pack shos significant loss of useable flying time... time to trash it. (take the bad pack to Radio Shack... they have a NiCd recycling program)

NiCads are probably the most dependable type of battery for our use as they will put up with more improper usage than any of the others. They do have a lifetime though as all things do, NICads are typically good for 1000 charge/recharge cyles (twice as good as NiMh). One way to ruin them though is to reverse charge them and that is what is likely to happen if you discharge your battery by just turning on the transmitter and leaving it until the battery is down. The weakest cell will most probably get a reverse charge doing that and will probably be permanently damaged. The other thing that will ruin them is to fast a charge or a fast charge that is left on to long. If you detect any fluid or swelling , pitch the battery, it is no longer going to be able to function to full capacity even if the voltage measures okay. The fluid is basic (not an acid) but is still corrosive. If there is fluid, the seal at the positive end has been compromised and is non repairable. A leaky NiCad will also contribute to the dreaded Black Wire Disease in your electonics so clean up any leakage ASAP. The advice above to never run your tranmitter with the antenna collapsed for any length of time is very valid. The SWR (standing wave ratio) goes way up and the energy normally transmitted as RF is now converted to heat in the final of your transmitter. This will definately shorten the lifetime of your transmitter and could possible cause an instantaneous failure.

As stated, but I wanted to make sure you understood it clear and didn't miss it with the other texts,

Don't leave the antenna down when you leave the radio on, it will trash the radio.

Also, don't discharge the batteries as far as you did. You can do irreversable damage to the cells.

Have fun. Its a good radio.