Hi there,

I have had my radio set (JR) for about 18 months now and I have never cycled my batteries. Someone at the my club mentioned that NiCads can develop a 'memory' and if you don't cycle the batteries every now and then, that is, fully discharge and fully charge a few times, then the batteries could fail.

I've got a charger that will do this for me and the RX pack is pretty easy to do but my question is about the TX pack. Can I cycle the batteries through the normal charging jack in the TX or should I be taking the battery out of the TX to do this?

I had a bit of a dig around the net and couldn't find any charge leads with that little white connector that the JR TX batteries use so is there some way of making up my own lead if I have to?

Thanks, FJ

Today's Ni-cad batteries do not develop memory.

You will not be able to cycle your transmitter battery through the charging jack. The radios have a diode that protect the battery from discharge installed. If you want to discharge the battery you will need to remove it from the radio. As far as the jack is concerned, you could actually just use a couple of straight pins. Stick them into each side of the jack and then connect the wires from the charger to the pins. But be very careful that the pins do not touch each other or you will more than likely fry your battery and short out your charger.

Ken

Thanks for the info RCKen.

I do a lot of fast charging and to balance my batteries I cycle both the Tx and Rx and have always been able to cycle my 10X thru the charge port. Some of the early Futaba radio's ie: 8UA you had to remove the battery to fast charge and cycle, but now even the 9-C can be fast charged and cycle thru the port I believe. Dennis

Weither or not you can cycle the batteries inside that expensive radio do you really want to?
I know the odds of something bad happening are low but for my money why take the chance. A new battery is much cheaper than a new radio.

Why would you want to buy a $50 battery just to make sure your cells are balanced. By cycling them you know when it's time to replace or recharge. Dennis

There is a difference between simple cycling and capacity testing.

The latter hlps to prevent disasters.

My tester does both. After it cycles it give me the ma of the battery. It can do four at a time, and can be set up to do it 3 times. Dennis

You missunderstood what I said or I didn't say it good.
I meant I would rather take the battery out of the TX to cycle it and if anything bad happens to the battery while cycling (which is rare but not unheard of) I would only be out the cost of the damaged battery and not the whole TX. To each his own.

Yup...

The implication to the non-initiated, was that cycling is all that is needed...

A good cycler/charger is worth the money.

In searching around I did find several MUCH higher capacity batteries that already come with the JR leads.

I believe these were in the 1800mAh-2000mAh range or above.

However you can go one better if you know how to solder.

Just clip the wires off an old spent battery.

Cut the wires, stript the ends. Twist each one and "tin" them with a bit of solder.

Do this to a new higher capacity battery pack... just DO NOT let the two wires touch each other at any point!

Put a piece of heat shrink tubing on to the wires and remove from the area you are about to heat.

Twist the like colors together and heat with your iron until the solder runs.

Let cool, then slide the heat shrink tubing in place and hit it with a heat gun.

Repeat for the other side and you're done.

"I had a bit of a dig around the net and couldn't find any charge leads with that little white connector that the JR TX batteries use so is there some way of making up my own lead if I have to?"

most remote/cordless phones have that white connector, anywhere that sells those phones and or batteries commonly have them in a scrap bin if you ask for them, the only thing you have to do is cut them off close to the battery and observe polarity when you connect them up. i use a little dab of solder and cover with heat shrink tube, works fine, i have made four packs lately for friends with JR radios .
hope it helps.

http://www.maxxprod.com/mpi/mpi-5.html

Is it item #2805 or #2803 on this page? I'm not that familiar with JR.

Yes, the Futaba 9C can be cycled through the charge port because Futaba uses a poliswitch instead of a diode. On lesser Futaba transmitters you do have a diode.

Your choices are jumping the diode (and voiding your warranty) or sending the TX into Futaba to have them put in a poliswitch ($20). You can also buy a poliswitch from Futaba.

Polyswitches come in many "forms" or configurations.
http://circuitprotection.com/radial.asp
Operational characteristics
http://circuitprotection.com/07catal...chTechFund.pdf

You can't discharge the batteries in lots of different Transmitters with your cycler, but you most certainly can discharge them very easily.

Pull out the antenna and turn on the TX. Now go about your latest building project. Watch the meter on the TX and turn the sucker off when it shows the battery is discharged. It takes awhile, and isn't high tech. But it certainly discharges the sucker. And that's the first step in cycling.

How low a reading do you look for? Whatever voltage your cycler says it's going to take it's discharge to.

You won't get a readout on the capacity dumped on that discharge. But what actually matters is the info you get from your charger when you recharge that battery.

You know, just because some things are not possible with our high tech stuff, doesn't mean they're no longer possible.

The page shown by the link lists which JR TX's the #2805 covers, and shows the #2803 is for only the newer JR8103's white battery plugs.

Good link. Didn't realize that stuff was back there on the back pages of that website.

There is another, the 2420 for JR PCM 10 per the site.