It is difficult for us to decide from only information "a sealed rechargeable lead battery of 6V-5Ah". Could you please give us more detailed information as below?:
2) Model name or number
3) How do you use it? Why do you need it?
4) All your measures to use it safely
5) Are there any means to get it near the venue when you can not take it out from your region?
6) Please attaching photos which we can see how it is built-in
As soon as after getting detailed information from you, we will have a discussion within OnStage TC/OC and then decide.