Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I would like to advise you:
- when there is a battery check condition, first
1. you figure out which battery is bad
2. you replace that battery, then
3. you have to enter your code and another key, or a code-and-key combination, to clear the battery alert/battery check condition in memory, which will persist even when the battery is now A-OK.
In other words, the battery check condition does not clear itself. It persists in memory, and must be cleared manually, with a code entered to authorize the clearing of it.
In some panels this clearing sequence is
But in a Vista 20p panel, it seems you just have to have everything hooked back up OK.
Note: with an Ademco panel, if you connect the battery and re-apply the AC power within 30 seconds of each other, this can clear the fault by itself.
Tell me if there are further problems, please. And I will advise you further. Thanks.