Cannon Safe Battery Replacement: Which Battery, How Often, How

Short answer: Cannon safe battery replacement is a five-minute job on the outside of the door. Most Cannon locks take one 9V alkaline battery; the type G biometric lock takes four AAA. Use Duracell or Energizer alkaline with an expiration date five years out — no lithium, no rechargeables. Open the safe first if you can, remove the keypad face or ring, hold the battery connector (not the wires), swap the battery, and test the code with the door open. Your code survives the swap.

Cannon publishes battery guidance on its FAQ, on a dedicated battery replacement page, and in a separate manual for each lock type. This page pulls them together, flags where they differ, and tells you which document to trust for your safe. For the brand overview, see our Cannon Safe brand page.

Which battery your Cannon safe takes

Cannon's manuals list two battery setups:

• One 9V alkaline — lock types A, B, C, D, E (SecuRam EntryPad), F, H1 and H2.
• Four AAA alkaline — lock type G, the biometric keypad.

The brand matters to Cannon more than you'd expect. The battery page and FAQ recommend all-alkaline Duracell or Energizer batteries with an expiration date five years in the future. The "two beeps but won't open" FAQ goes further: "100% Alkaline, no lithium, non-rechargeable." Cannon's battery page also says not to mix old and new batteries, which matters only on the four-AAA lock.

Check the date on the package before you buy, not after. Cannon's battery page says a battery that dies within days or weeks is often expired — "even if it has just been sitting on a shelf."

How often to do a Cannon safe battery change

Here's where Cannon's documents disagree, side by side:

Cannon document	What it says
Lock manuals (A–F, H1)	Batteries last about 1 year under normal use; test every six months
Lock type H2 manual	Change the battery every 6 months under normal use
Lock type A recommendations	Change battery at least every 6 months
FAQ and battery page	Change it twice a year; more often with heavy use
Warranty page	Battery should be changed yearly

The warranty number is a condition, not advice. The page says the warranty is "contingent upon proper installation, use, and maintenance," and lists a yearly battery change as part of that. The manuals and FAQ ask for more. I'd follow the FAQ: twice a year, on two dates you'll remember.

(Five documents, three intervals, one battery. The battery didn't get a vote.)

Low-battery warning signs, by lock type

The signal depends on which lock is on your door. From Cannon's manuals:

• Types B, C, E and H1: a red indicator light appears after pressing any button.
• Types A, D and F: the lock beeps repeatedly while unlocking.
• Type H2: a green and red indicator light after pressing a button. If both stay on together, the manual says the battery is installed backwards.
• Type G: an illuminated red light on the keypad when opening.

Cannon's FAQ adds two general notes. The low-battery light flashes only while you're entering the combination. And you may hear the battery dying in the way the lock sounds.

The keypad was still lit. That's what made it dangerous.

Cannon safe battery replacement, step by step

Cannon says to open the safe first if you can, and leave the door open throughout. Its FAQ calls that "always good practice" when working on the lock or keypad. Then follow the steps for your keypad style.

Before you start, on every lock: hold the battery's connecting cap when you disconnect or attach it, and don't pull on the wires. Every manual we read repeats this warning, because pulling the wires "could cause the power supply to disconnect from the lock."

Keypad face with a tab (lock types A–D, F, G, H1, H2):

1. Press the tab and turn the keypad face to remove it.
2. Disconnect the old battery, holding the connector.
3. Connect the new battery and seat it.
4. Screw the keypad face back in place.
5. Test the code with the door open.

NL keypad (as shown in the A/D and F manuals): find the battery tray on the bottom of the keypad, slide the battery door open, pull out the battery plug, connect the new battery, slide it into the tray, close the latch, and test the combination before shutting the door.

SecuRam keypad (Cannon FAQ): twist the keypad ring clockwise and pull it off, connect the battery, slide it into the tray, put the ring back and twist it counterclockwise, then test before closing the door.

SecuRam EntryPad (lock type E): turn the housing ring counterclockwise until it stops — about 20 degrees — and pull it off. Push the battery from the bottom left and unsnap it. Snap the new 9V onto the clip and push it back in from the right, tucking the cable so the ring doesn't catch it. Line up the three tabs with the three grooves and turn the ring clockwise until it clicks.

Type G (four AAA): remove the battery cover, insert the batteries matching the polarity marks, replace the cover and screw the keypad back in place.

Notice the twist direction isn't the same on every keypad. The FAQ's SecuRam keypad and the manuals' Lexam and EntryPad keypads each describe their own. Follow the sheet that matches the keypad on your door.

Cannon safe battery dead: getting back in

A dead battery is the case people search for in a hurry. Cannon's FAQ answers it directly: "For added security there is no other way to get into the safe." Then the good news: "the battery compartment is located on the outside of the safe so you can still change the battery and regain access."

So the steps for a Cannon safe battery that died are the same steps as above, with the door closed. Remove the keypad face or ring from the outside, swap the battery, put it back, and enter your code.

Your code is still there. Cannon's FAQ says the combination is stored in the lock's computer and is not affected when the battery dies or is changed.

If a fresh battery doesn't wake the keypad, or the lock beeps and the door won't open, the problem is elsewhere. See Cannon safe won't open. If the keypad wakes up and then ignores your code after a few tries, it's lockout mode, and the H2 manual warns that removing the battery during a lockout restarts the penalty time.

Here's the catch: the warranty covers the lock, not the battery

Ding. Cannon's warranty page excludes "weak or dead batteries" from coverage, along with lost combinations and improper opening procedures. It also makes a yearly battery change part of the maintenance the warranty depends on.

Read those together and the message is plain. A lock that won't open because the battery is two years old is your problem in writing, not Cannon's. Electronic locks have a five-year limited warranty on the same page — parts and labor in year one, parts only after that — but the battery isn't part of the lock.

The second catch is the battery itself. Cannon's documents specify alkaline and steer you away from lithium and rechargeables. A battery that's the right size but the wrong chemistry may fit perfectly and still fail the lock.

If the safe stores firearms and children live in or visit the home, plan battery changes for times when you can stay with the open safe. Keep the code written down somewhere secure, away from children and not inside the safe, as Cannon's manuals say.

Skip it if: when you don't need a new battery

• Your safe has a mechanical dial only. No battery involved. Type F has both — the battery runs the keypad, the dial is mechanical.
• You changed it recently and the keypad still misbehaves. Check the expiration date, then call Cannon customer service.
• The safe is a GunVault. Cannon's FAQ covers GunVault MiniVault and MultiVault batteries separately, with the door open and the unit upside down. Follow that unit's manual.
• You're shopping, not fixing. Look for an outside-access battery and a documented backup before you buy — our gun safes page explains what to check.

That's it. Buy two 9V alkalines dated five years out, put one in the lock and one in the drawer. Then put two dates on the calendar six months apart, and change the battery on those days — not the day the keypad goes dark.