When did you last clean your plugs?

[graememarion]

I was checking a four cell battery pack that I had laying on the bench today with surprising results.

My battery checker has an expanded scale and puts a 250 milliamp load on the battery.

This battery had not been used for several weeks and recorded an unsatisfactory 4.3 volts under load.

On impulse I squirted some electronic cleaner into the plug and tested again without charging. This time the reading under load was 4.7 volts. Still unsatisfactory, but an increase of .4 of a volt over the first reading.

This made me think that this high resistance problem would probably happening with the servo plugs. I don't know of an easy way to test this theory.

I think it might be cheap insurance to occasionally give all the plugs and switches on one's model a dose of electronic cleaner.

[bananaman]

If its a nicad pack it might have black wire. That can affect plugs too.

[graememarion]

It is a 170 Mah NiMH pack for a DLG.

It is three months old and gets plugged directly into the receiver without using a switch.

It charges up fine. The point I was making was that the plug had developed a high resistance that was fixed by a dose of electronic cleaner.

NiMH packs have a tendency to self discharge if they are left sitting unattended on the bench for several weeks. This is normal.

[bananaman]

One of our club members with an electronics background did a test on various manufacturers of the JR style plug and found differences in pin diameter and socket tension. He proved via demonstration using a single pin out of a plug the variations of tension even within a 3 socket plug. A thinner pin and weak socket will have higher resisitance and be far more prone to come out unintentionally. Hence why I and many others don't use the typical plugs anymore for "switch" duty.
I believe I've lost 2 models that way.

There's part of a thread talking about it around here somewhere.

Its good you check your batteries before you get to the field. Some modellers out there don't.

Also just for any one reading this, some "contact cleaners" leave a residue which can make it worse. It should say on the can "residue free"
I use CRC Contact Cleaner for anything electronic, don't use CRC 2-26 or WD-40 or anything that says water displacing.

[ezza]

Whoops wrong thread.

[graememarion]

Battery/servo plug contacts can develop a resistant coating over time. This is where the electronic cleaner spray can help.

The act of plugging in and unplugging battery/servo plugs makes the contacts slide over each other. This sliding/rubbing action helps to clean the contacts. Continual plugging in and unplugging will eventually wear out any protective plating that was put in place by the manufacturer. Plugs have a limited lifetime.

This self cleaning action is one reason why R/C manufactures supply slide switches and not toggle switches.

I don't know how to test for high resistance in servo plugs. I just think it makes sense to give them a squirt of electronic cleaner once in a while. Treat your switches to a dose while you are at it. They will thank you for it.

If you have never heard of electronic cleaner spray, then just ask at "Tandy's" or "Dick Smith's." They sell it.