the fully seal gel batteries like oddysey or optima are legal
"sealed" lead acid are not - these ones are called sealed since they dont require the addition/replacement/topup of fluid
http://www.energymatters.com.au/renewable-...adAcidBatteries
Sealed Lead Acid Batteries
Sealed lead acid batteries are also known as valve regulated lead acid (VRLA) batteries, recombinant batteries and often called maintenance-free lead-acid batteries. Examples of VRLA batteries are:
Absorbed glass mat (or AGM)
Gel cells
The term term "seal lead acid battery" is misleading: a sealed battery would be a safety hazard due to overpressure risks the battery is overcharged. There is always a safety valve present, hence the name valve-regulated. Even the term "valve regulated" does not really describe this technology. These are really "recombinant" batteries. This means that oxygen evolved at the positive will mostly recombine with the hydrogen ready to evolve on the negative and thus prevent water loss. The valve is only a safety feature in case dangerous amounts of hydrogen are produced.