Well, don't feel too bad. Our Survivairs have been going through low air alarm batteries at the rate of about once a year. These are in the air gauge and are 6 or 9 volt camera style lithium batteries.
All the " Buddy Breathers" are compatible as long as they meet the NFPA 2002 standard. The RIC Fitting where you hook up the bottle is the same fitting for all SCBA. The only thing is MSA can give and recieve air, while the others can only recieve it. Unless they have their own systems.