VRLA lead acid batteries should not vent unless overcharged, they are used in UPS's everywhere, not sure what the permitting issue would be. Lithium Iron batte

VRLA lead acid batteries should not vent unless overcharged, they are used in UPS's everywhere, not sure what the permitting issue would be. Lithium Iron batteries which are what's typically used in stationary backup are extremely safe and do not burn as hot compared to more unstable high energy density chemistries like NMC typically used in mobile applications. They are also relatively inexpensive and have extremely long lifespans if not used in extremely hot environments, we are talking 20 years to 80% capacity in a stand-by application.