replace mains adapter with Li-poly rechargeable - possible?

[turnbui 0]

hello everyone,

i have a mains operated CCTV camera that has a 12v 2A dc mains adapter. i have no idea what it draws when saving a 10 second night vision motion to on board microSD card. Would it be possible to replace mains adapter with a Li-poly rechargeable batt and need charge say once month or better?

thanks