ADT's No AC Power article explains the Base's power. The Base runs on AC power from an outlet that is not switch-controlled and has a backup battery for up to 24 hours. A No A/C message in the app, or the power LED on a device blinking red once every second, means there is no AC and the device is on backup battery; blinking red once every two seconds means no AC and a low backup battery.
The checks in more detail
On a keypad the Disarm button is solid yellow and the LED blinks red every two seconds when awake, and a keypad waits two minutes after AC loss before entering backup mode. Check for a power outage, check the power cable is firmly in the outlet, and check the outlet works by testing another device, including any wall switch. After power returns the device may show a Low Backup Battery message for up to six hours while it recharges. If it still has no power after these checks, the device needs replacing and ADT chat can help.
ADT also lists battery types for devices in its low battery article, and its keypad article has a replacement backup battery article. Keep the Base away from temperatures above 122 or below 32 degrees Fahrenheit, which degrades battery life. Note the date of any outage and how long the Low Backup Battery message lasted afterwards. Extreme heat or cold shortens backup battery life, so keep the Base in a moderate room. Keep the outlet the Base uses free of switches.
The Base's backup battery is meant for outages, not daily use, so a Base that often runs on battery points at a loose plug or a switched outlet, not a bad battery. The keypad and the Base both run on AC with a backup battery, and ADT notes that the keypad waits two minutes after AC loss before switching to backup, so a brief flicker of power will not immediately trigger the low backup messages. Test the Base's outlet with a lamp for a day before trusting it, since an outlet that fails only when warm is easy to miss.
Differential
Likely causes of “ADT Base has power or battery problems”, and how to tell them apart
- 1
A power outage
What separates it A No AC message appears in the app or the power LED blinks because mains power to the Base has been lost
How to confirm Wait for power to return, and check whether the rest of the home has lost power as well
- 2
A loose plug
What separates it The power comes and goes in a way that suggests a loose plug or a poor connection at the wall
How to confirm Reseat the power cord firmly at the Base and at the outlet and check that it stays seated
- 3
A switched or dead outlet
What separates it There is no power at all to the Base and the outlet may be switched or dead
How to confirm Use a continuous, working outlet and test it with another device before plugging the Base back in
- 4
Recharging after an outage
What separates it A Low Backup Battery message shows after a power cut while the backup battery recharges
How to confirm Wait up to six hours after power returns for the backup battery to recharge fully
- 5
A failed battery
What separates it The battery runs down much faster than the 24 hours ADT gives for a fully charged backup
How to confirm Contact ADT to have the battery checked, because a failing backup battery cannot be fixed at home
Before you touch a setting
Record this first — changing settings destroys the evidence
- The LED blink pattern and how often it blinks, once or twice per second
- Which outlet the Base is plugged into and whether another device works in it
- How long ago power returned after any outage
- The temperature around the Base, since heat and cold both harm the battery
Try in this order
0 of 7 completedCheck for an outage
ReversibleCheck whether there is a power outage, recent or current, because a No AC alert during a cut is normal and clears itself when power returns.
Reseat the power cable
ReversibleReseat the power cable at the outlet and at the Base, and make sure the cord is not pinched or stretched tight behind furniture.
Test the outlet
ReversibleTest the outlet with another device such as a lamp, so you know whether the outlet works before you blame the Base or its cord.
Check any wall switch
ReversibleCheck any wall switch that controls the outlet, since a switched-off outlet cuts power to the Base and it then runs only from its backup battery.
Wait up to 6 hours
ReversibleWait up to six hours for the backup battery to recharge after power returns, and do not judge the battery before that time has passed.
Read the LED pattern
ReversibleRead the LED pattern once the power is back: a blink once per second or once every two seconds tells you how much backup capacity remains.
Contact ADT
ReversibleContact ADT if the Base stays dead or the battery keeps running down, since a faulty backup battery or power supply needs to be replaced by ADT.
Model-specific
What is true of this model and not of its siblings
- Backup
- Up to 24 hours on battery.
- Recharge
- Up to 6 hours of low battery message after power returns.
Stop boundary
When this stops being a self-service repair
- !If the device still has no power, contact ADT through chat
- !If the battery will not hold charge, contact ADT
- !If the outlet turns out to be faulty, plug the Base into a different outlet that always has power
Evidence ledger
Sources behind this answer
AC power and backup battery.
Battery types and lives.
Base setup and placement.
Base LED patterns.
The company and its products.
Exact questions
Common questions
How long does backup last?+
The backup battery in the Base keeps it running for up to 24 hours after mains power fails, which is enough to ride out most outages.
What does a red blink each second mean?+
A red blink once every second means the Base has no AC power and is running on its backup battery, so restore mains power as soon as you can.
What does every two seconds mean?+
A red blink once every two seconds means there is no AC power and the backup battery is low, so the Base will shut down soon.
How long is the low battery message after power returns?+
A low backup battery message can remain for up to six hours after power returns, while the battery recharges, and then it clears by itself.
What temperatures hurt the battery?+
Temperatures above 122F or below 32F can harm the backup battery, so keep the Base away from heaters, sunny windows and unheated spaces.
Does the keypad wait after AC loss?+
The keypad waits two minutes after AC power is lost before it reports the loss, so a brief power blip does not raise the alert at once.
What temperatures should it avoid?+
Avoid keeping the Base above 122F or below 32F for long, since extreme heat or cold can shorten the life of its backup battery.
What wifi bands does the Base use?+
The Base joins a home network on either the 2.4 GHz band or the 5 GHz band, so most current routers will work with it.
Does the Base need cellular?+
Yes, the Base needs a cellular connection for its link to ADT, so cellular signal at its location matters as well as wifi.