Allen-Bradley controllogix 1756-L55M12 - Estimate Warning Time

Publication 1756-UM001G-EN-P - January 2007
Maintain the Battery 127
Estimate Warning Time
Use this table to estimate the battery life after the low-battery warning
(BAT LED = solid red). Use these times whether or not the controller
has power. There is always a small drain on the battery.
IMPORTANT
When you power up the controller, see if there is a low-battery warning. If you get a
low-battery warning for the first time, you have less battery life than this table
shows. While powered down, the controller still drains the battery but it cannot give
the low-battery warning.
Temperature 2.54 cm.
(1 in.) Below the
Chassis, Max
Power Cycles Battery Life After the BAT LED Turns Red (Worst Case)
Project Size
1 MB 2 MB 4 MB 8 MB 16 MB
0...20 °C (32...68 °F) 3 per day 26 weeks 18 weeks 12 weeks 9 weeks 5 weeks
1 per Day 26 weeks 26 weeks 26 weeks 22 weeks 13 weeks
1 per Month 26 weeks 26 weeks 26 weeks 26 weeks 26 weeks
21...40 °C (69.8...104 °F) 3 per day 18 weeks 14 weeks 10 weeks 8 weeks 5 weeks
1 per Day 24 weeks 21 weeks 18 weeks 16 weeks 11 weeks
1 per Month 26 weeks 26 weeks 26 weeks 26 weeks 26 weeks
41...45 °C (105.8...113 °F) 3 per day 12 weeks 10 weeks 7 weeks 6 weeks 4 weeks
1 per Day 15 weeks 14 weeks 12 weeks 11 weeks 8 weeks
1 per Month 17 weeks 17 weeks 17 weeks 17 weeks 16 weeks
46...50 °C (114.8...122 °F) 3 per day 10 weeks 8 weeks 6 weeks 6 weeks 3 weeks
1 per Day 12 weeks 11 weeks 10 weeks 9 weeks 7 weeks
1 per Month 12 weeks 12 weeks 12 weeks 12 weeks 12 weeks
51...55 °C (123.8...131 °F) 3 per day 7 weeks 6 weeks 5 weeks 4 weeks 3 weeks
1 per Day 8 weeks 8 weeks 7 weeks 7 weeks 5 weeks
1 per Month 8 weeks 8 weeks 8 weeks 8 weeks 8 weeks
56...60 °C (132.8...140 °F) 3 per day 5 weeks 5 weeks 4 weeks 4 weeks 2 weeks
1 per Day 6 weeks 6 weeks 5 weeks 5 weeks 4 weeks
1 per Month 6 weeks 6 weeks 6 weeks 6 weeks 6 weeks
EXAMPLE
Under these conditions the battery will last at least 20 months before the BAT light turns red.
• The maximum temperature 2.54 cm. (1 in.) below the chassis = 45 ºC (113 °F)
• You cycle power to the controller 3 times per day.
• The controller contains an 8 MB project.