battery fault

I've got a Battery Fault indicator on a Control Logix Processor after a little less than 2 years of operation.

Just curious what kind of battery life other people are getting.

We operate a maintenence program of replacing Batteries once a year, the cost of a battery is so small in comparison to even half an hours lost production it is not worth taking the risk by not replacing them.

Its a tedious job of replacing all those batteries and most of the newer smaller PLC's now have a memory card that stores the program so you don't need a battery backup.

Barry

I had a battery failure on a Control Logix after only 2 months, replaced the battery and has been OK for 6 months now. Other Control Logix PLC's in the plant have been OK for over 3 years.

Makes you think there is a bad batch of batteries about.

We had a communication from AB stating that Control logix battery life is vastly reduced compared to SLC's.
I was told, by AB, that battery life is proportional to the memory of the processor i.e. a CLX has megs and an SLC has K's.
Whether this is the case or not, I'd agree with the previous writer and change them often.

The battery life of the supplied battery (1756-BA1), acording to AB is 30 days. What I have been doing and is highly suggested by AB, is to buy the extended life battery pack (1756-BATM). It has a 300 day life span, when the proccesor is off. Its a din rail mount and you can buy replacement for that pack (1756-BATA).