Replacing PLC batteries 1

[snorkles]

My Mitsubishi PLC's lithium battery is nearly 5 years old.

Problem #1 This 2 pin connected, ER17330v/3.6volt battery as it seens, is very elusive. I need a reliable battery cross reference or a distributor.

Problem #2 What are the do's and don't's to changing these batteries?

Thanks!

 

[jdkasper]

Which Mitsubishi PLC are you using?

This will work for the FX series.
Search Newark for a 3.6v lithium battery. You should be able to find one with solder tabs. Use your existing lead on the new battery.

http://www.newark.com/

Change the battery with power on to the PLC. If the PLC does not have an eprom, the program will be lost if the battery is removed with the power off.

 

[snorkles]

Thanks for the info Jdkasper...We are using a general purpose Mitsubishi MELSEC-A type AOJ2 controller.

The search for a direct fit battery is now over. Your suggestion of taking Newark's PLC 3.6 volt with tabs and soldering on the 2 pin connector makes good sense.Thanks!

 

[buzzp]

Dont touch the battery with your hands if it is a coin type, it will reduce the life of the battery.

 

[Skogsgurra]

buzzp,

What happens if you touch the battery? Is this a modern myth? Or are there some real facts behind this recommendation?

 

[buzzp]

If it is a coin type, the mfg will tell you the same thing. No myth about it but often an over looked handling precaution.
Think, your fingers touch both sides of the coin, draining the battery slightly. Now remove fingers and you leave a nice greasy film there, often completing the path from one side to the other with low resistance.

 

[Skogsgurra]

No way, buzzp. Unless you do the battery change right after you have eaten without washing your hands afterwards ;-)

 

[Skogsgurra]

Regarding greasy hands:

The Germans have this little rhyme (they seem to have switched something):

Vor dem Stuhlgang, nach dem Essen
Hände waschen,nicht vergessen!

A rough translation would be:

Before the toilet, after eat
Wash your hands - and do not cheat!

 

[buzzp]

I dont care how many times you wash your hands, they still leave oily deposits. Thats why we leave finger prints all over the place.
Believe it or not, your choice.

 

[Skogsgurra]

I think that my choice is obvious ;-)

 

[buzzp]

It is simply a precautionary measure. I am not saying it happens every time. But remember old man Murphy? Likely to happen to your best client at the worst possible time.

 

[Skogsgurra]

OK, buzzp. Do you also wear a safety belt in you TV chair?

I mean: It could prevent you from an accident if worst comes to worst. But are all these "close to zero worth precautions" really worth it? Putting too many precautions into a routine will eventually have the opposite effect because people get "overloaded" and forget about the more important precautions - like wearing a safety belt when driving a car or taking anti-ESD precautions when handling sensitive circuitry.

Safety measures that cannot be explained and/or clearly demonstrated will undermine safety in the long run.

I need to be firm about these things, there are too many myths walking around on the surface of the earth.

 

[buzzp]

Well I don't know what to tell you. In a mfg environment where these batteries are inserted by the hundreds or thousands, it is definately worthwhile.

It is not even comparable to your analogy. Call a mfg and tell them you are using 500 of these a year and ask them what handling precautions you should take.

Do you often ignore mfg's recommendations? Don't they know best? Sure they may be overly cautious but this simple step of not handling the batteries with your bare hands is an easy step and costs nothing, it is not a time issue either.

What don't you understand about oil in/on your skin? Where do fingerprints come from? Imagine some production person putting in these batteries on a production line without any reference to handling precautions. I hate to imagine that. If you can't understand that then your best bet is to stay in the harmonic distortion arena. And if Siemens or ABB use lithium coin cells in their drives, I will expect a shorter than a ten year life.

The beautiful thing is, I know what is right and have no further need to justify my statements. The poster is encouraged to contact a mfg with the above question.

 

[Skogsgurra]

We have very different perspectives on this issue. I change a battery now and then - perhaps five batteries each year. So the trouble of finding clean (I mean clean) gloves for that job would be a little too much. It is different in a production environment There the gloves can be part of the environment - no big deal.

If this were important, the manufacturer should have some instructions about gloves printed on the package - but I have not seen anything about it so far. Yes in the Panasonic manual for Lithium batteries, but I am not sure if it is to protect the batteries or the worker.

About acid and fat on your hands. Yes I have worked with the gage-block manufacturer C E Johansson (Jo-Bloks) and this was a very important theme. But mostly because you could get corrosion from some peoples' hands. And that would destroy acuracy. I do not think that a finger print really does any harm on the surface of a battery. No.

I do most of my work for Siemens nowadays. And the rules for changing back up batteries never mention anything about gloves. Nor do the ABB manuals.

Sorry if you think that I am doing this on a personal basis - it is not so. And I hope that thinking about the different views that we have can help understand that.

Best regards
Gunnar Englund

 

[buzzp]

Ok, I checked Panasonics web site. They say they should not be handled on the basis of contact resistance being abnormally high. This is a little different than my statements although I believe my explanation is valid as well.
If your just changing a battery in a PLC, just limit the handling of the battery. In a production environment, tools are easily found with insulation on them to avoid the possibility of reduced life.
Panasonic has a neat little table showing the recovery time (as far as voltage-no reduced life chart) after a short between the terminals. Granted, oily film will likely not result in a real short, however, it will continuously discharge the battery.

 

[jlhmaint]

snorkes no need to solder these batteries. we have all kinds of old and new mitsubishi plcs at the shop we replace the batteries all the time in them. And we have a direct match up for all batteries. Tomorrow at work i will get you some info. As for replacing batteries the general rules follow:

1: always have a back up of the plc ladder just in case
2: always leave the power on never believe the mfg saying that you have 60sec or what ever.
3: never forget #1 or #2 or you could be having a long day.
email me at jholston@columbus.rr.com and i will send you some info late monday night i work second shift.

 

[jlhmaint]

Sent you the info at your email let me know if it works out.

 

[tentoes]

It's time to change batteries on a Allen-Bradley 2711-KC1
Terminal Keyboard/Color Chart ( Panel View ). I have not opened the Panel yet and have not researched battery type.
Thanks,
tentoes