Thanks heaps, Its not for too heavy use, just need it to go for 6-8 hours, and dont need it to recharge.
Not set on any bulbs, but I was looking at this (https://www.entosupplies.com.au/equipment/field/collecting-lights/compact-self-ballasted-black-light-28watt/) UV bulb as it was from a local entomology company, unsure for the second bulb.
The same company also sells 12 volt, 14 & 26 AMP acid lead batteries if either of those would be suitable for a 2 bulb set up?
https://www.entosupplies.com.au/equipment/12-volt-14-amp-hour-lead-acid-battery/