For clarification on which batteries to use, here are a few tips:
- Always use 4 x AA batteries (alkaline only) for replacements (we highly recommend the Energizer Max).
- Any 4 x AA alkaline batteries will work.
- Do not use lithium batteries.
- Do not use 9V batteries.
- Do not use rechargeable batteries (as their voltage can drop in hot/cold weather conditions).
- When the batteries need changing, the red LED will be permanently lit (the red LED always flashes every 30 seconds when the door is CLOSED).