hp 41-CV battery cover

3 models:
1 is a closed pack.
2 same as 1, with a lateral hole to install inside a LiPO battery or Ni-CD or Lithium rechargeable battery pack with charger and protection (see online for the electronics)
3 the original one to carry N-size batteries (1,5v @12mm dia x 30mm length). Reminder: A-23 batteries are almost same size but 12V(!!!) Be careful.