Omron SYSMAC CJ Operation Manual page 50

Unit components
2-1-3-1 Battery lifetime
2-1-3-2 Low-battery indicator
2-1-3-3 Replacing the battery
Note
38
The maximum lifetime of a battery is 5 years when the ambient temperature is
25°C. The lifetime of the battery is shorter when the ambient temperature is
higher. The lifetime of the battery is also shorter when there is no power supply
to the unit for long periods.
If a low-battery error occurs, the ERC LED flashes, the BATTERY_LOW
parameter is ON, and bit 3 of status word n+2 is set (see section 3-3-1-2). If
this occurs, perform the following steps:
1 Check if the battery is installed correctly.
2 If the battery is installed correctly, replace it.
When a low-battery error occurs, the battery can continue to function for 5
days if the ambient temperature is 25°C and if power is supplied to the PLC
system at least one time per day. If the power is not turned off until the battery
is replaced, the battery failure and the resulting loss of RAM data can be
delayed.
If the ambient temperature is more than 25°C, the battery can only continue for
less than 5 days. If the ambient temperature is 40°C, the battery can continue
for 4 days. If the ambient temperature is 55°C, the battery can continue for 2
days.
When replacing the battery, make sure that the following is adhered to:
• Use the CJ1W-BAT01 as a replacement battery.
• Do not use a replacement battery that is older than 2 years. The production
date of the battery is shown on the label, in the format yy-mm, where yy is
the year and mm is the month.
Production date of the battery: March 2008.
• Make sure that the sensitive internal components of the CJ1W-MCH72
cannot be damaged by static electricity when the battery is replaced. This
can be done in two ways:
1 Turn the power off. (This is the recommended way.)
2 Leave the power on, and touch a grounded piece of metal to discharge
static electricity before replacing the battery.
• Make sure that an experienced technician is in charge when the battery is
replaced. This is required by UL standards.
To replace the battery, perform the following steps:
1 Make sure that the power to the unit is on for at least 5 minutes.
2 Turn the power to the unit off.
You must perform the following steps within 5 minutes. If you do not perform the steps
within 5 minutes, the RAM can be deleted.
3 Open the battery compartment.
4 Remove the old battery (A) from the battery compartment.
CJ1W-BAT01
08-03
Section 2-1