ABB AC 800M

Changing the Battery Section 5 Maintenance
120 3BSE 027 941 R301
Changing the Battery
Internal Battery
The internal battery is mounted inside the PM8xx processor unit. Since the battery
is not rechargeable, it is important to exchange it on a regular basis (refer to the
Maintenance Frequency Schedule for further details). For details of correct battery
polarity, remove the right-hand cover from the battery housing (see see Figure 33 on
page 121 and Figure 34 on page 122).
Specifications for the internal battery:
• Type: Low-rate lithium battery, 3.6 V, 950 mAh.
• Size: ANSI Size ½ AA / IEC size ½ R6
• Lithium contents: 0.3 g
The battery must be exchanged whenever:
• the PM8xx B(attery) LED flashes or is extinguished.
• multiple or extended power cuts have occurred.
• extended periods of system downtime have occurred for maintenance or
malfunctions.
For reasons of safety, exchange the battery only when the AC 800M is powered up.
Due to the batteries being connected in parallel, it is necessary, when using the
SB821 external battery, to remove the internal battery from the PM8xx in order to
avoid reducing available memory back-up time. In addition, status monitoring is
only provided for one battery.
It is possible to replace the internal battery with the AC 800M Controller online.
However, be sure to observe standard safe working practices at all times.