Hello
We need to know the allowable storage time of 6ES79710BA0 siemens backup battery without becoming empty.
Thanks

 

There is simply no available data - Siemens don't give anything away:
https://mall.industry.siemens.com/mall/en/ww/Catalog/Product/6ES7971-0BA00

The data sheet provides even less information:
https://support.industry.siemens.com/cs/pd/240552?pdti=td&dl=en&lc=en-WW

However the battery is fairly substantial and appears to work well in a S7-400,
So a 10 year life span would not seem unreasonable.

However I've never seen any reason to question battery life in any PLC related backup scenario;
If the PLC is powered it would give a 'low battery alarm' at the right time.
If not powered for several years I would expect a dowloaded application program with supporting hardware to be available. Battery support would be, more or less it's shelf minus say 1 year which gives us 9 years.

If you have a PLC unpowered for such a long time. I wouldn't expect it to work anyway. Only once have I gone through 2 racks checking all edge connector contacts on a stored PLC5. Battery and associated contacts were good and program retained.

 

Hello,

The charge hold time depands on the battery temperature and stae of charge:

More info on this page of the battery university:
https://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries

Bertus

 

Generally Only dry / non-rechargeable batteries are used for PLC battery backup;
and as indicated above - shelf and working life depends on environmental conditions.

I now recall way back in the late 70’s someone asked about a French PLC backup battery having a shelf life ‘probably less than 18months’ if stored in an unheated shed located near the Russian/outer Mongolian border where winter temperatures typically -25Deg C or lower.

 

Hello,

For a primairy battery have a look at this page:
https://batteryuniversity.com/index.php/learn/article/primary_batteries

Bertus

 

Hello All

I join this thread with the answer on this question

See following calculations depending on backup battery capacity...

Looking to hear back from you soon,

Any time!

James

 

Gentlepeople...
Don't forget... Ambient Temperature of the battery's location is extremely important !
Regards, Phil Corso

 

Hello All

I join this thread with the answer on this question

See following calculations depending on backup battery capacity...

Looking to hear back from you soon,

Any time!

James

View attachment 1328

Okay

I did efforts and you just cliked on "like" ...
My post desserve more than a "like" ...I provided the exact answer on the original post

And now I will make less than I did ..thanks to THE people who have a behavior like this one ...pfff

 

" I provided the exact answer on the original post"......
Maybe ! I thought the results were poor so tried Siemens Forums:

https://support.industry.siemens.co...harge-time-in-s7-400/5233/?page=0&pageSize=10

https://support.industry.siemens.co...the-length-of-the-backup-time-?dti=0&lc=en-WW

The op hasn't stated CPU model - seems battery current consumption varies dramatically depending type.

 

" I provided the exact answer on the original post"......
Maybe ! I thought the results were poor so tried Siemens Forums:

https://support.industry.siemens.co...harge-time-in-s7-400/5233/?page=0&pageSize=10

https://support.industry.siemens.co...the-length-of-the-backup-time-?dti=0&lc=en-WW

The op hasn't stated CPU model - seems battery current consumption varies dramatically depending type.

You just have to read my ^post and depending on battery capacity you can calculate Storage time thats it ...

 

It appears my links don't work, so lifted to pdf file ...