Low battery indicator

Check to see if the manufacturer recommends a specific type of battery such as a lithium ion or Ni Cad - Nickel Cadnium.

Check if your battery door is perfectly aligned and has no gaps if it has a gap then you have to push or tape it to line perfectly without any gaps and if the door perfect and still showing same thing you have change batteries make sure to use either Duracell or rechargeable 2.5v batteries

Are you sure you bought lithium cells? In your camera you should use Ni-MH batteries. The SNB-2512 could be very expensive, but normal Ni-MH from any brand should work fine.

Depending of what you use, always be sure all batteries are the same, charged and suited for your camera. Most of the time even new Ni-CD rechargeable batteries won't work, because the voltage is low, according to NiMH or alkaline batteries.
Always charge NiMH batteries before using them for the first time, or if they have not been used for a long period. 3 months is a very long period.
Always charge sets of batteries (2 or 4) together.
Do not use alkaline batteries unless it is absolutely necessary. In some cases, alkaline batteries may have a shorter service life than NiMH. Alkaline battery performance is limited, especially at low temperatures. The use of NiMH batteries is recommended.
Never use manganese (Zinc-Carbon) batteries in your camera.

Depending of what you use, always be sure all batteries are the same, charged and suited for your camera. Most of the time even new Ni-CD rechargeable batteries won't work, because the voltage is to low, according to NiMH or alkaline batteries.
Always charge NiMH batteries before using them for the first time, or if they have not been used for a long period. 3 months is a very long period.
Always charge sets of batteries (2 or 4) together.
Do not use alkaline batteries unless it is absolutely necessary. In some cases, alkaline batteries may have a shorter service life than NiMH. Alkaline battery performance is limited, especially at low temperatures. The use of NiMH batteries is recommended.
Never use manganese (Zinc-Carbon) batteries in your camera.

You have a bad battery, which means you'll need to get it replaced.If it's not holding a charge that indicates dead battery.

Don't use regular alkaline batteries (even though you can...) It's a pain to splurge for the more expensive lithium or photo-specific batteries, but they do last. I take A LOT of pictures with my A590, and can usually get several hundred shots out of a set of good batteries. Try Energizer's web site for a coupon, sometimes they have them available.

Clean the battery holder with a pencil eraser, otherwise go for good brand rechargeable battery AA 2700 mAh try it.

Even thou you have changed the batteries, the terminals could be contaminanted and are not making a good electrical connection. You should remove the batteries and clean the battery contacts inside the lock with some rubbing alcohol to clean off any residue, etc.

The beeping is a low battey indicator and if you've put in new, fresh batteries (always replace all the batteries at the same time), it can only be that the contacts are dirty.

Hope you find this Very Helpful - Best regard!

PS: All your pass codes will remain in the lockset memory even for extended periods of time without any batteries installed

Clarification of your battery/power led indicator:

Solid amber:
Battery is charging at 0% - 89% capacity

Solid green:
Battery is charging at 90% - 99%

Blinking amber:
Battery is low

Led is of:
Battery is charged

guido462:

new batteries - brand new? fully charged per spec?