Ultracell selaed lead-acid battery can be mounted in any position but charging is not recommended in upside down installations.
Technical specifications:

    Can be mounted in any position but charging is not recommended in upside down installations.
    Self-discharge: approx. 3 % / month
    Designed floating life: 4-5 years
    Cover: ABS
    Charge Voltage: 13.6-13.8 V (float use), 14-15 V (cycle use)
    Nominal voltage: 12 VDC
    Nominal Capacity (20 h): 1.3 Ah