For the past two and a half years that I’ve been moth trapping, I’ve been using a 20w actinic light which has served me very well, but I’d like to try out with using a mercury vapour bulb.
I’ve already got a battery and inverter, and now I just need to find the right light. I’m aware that there are two types of MV bulbs; those that require an external ballast and those that are self-ballasted. I’d like to use a self-ballasted one as there’ll be less parts (and wiring) to worry about.
So far I’ve found two strengths of self-ballasted MV bulbs; 80w and 160w (anything above 160w seems a bit overkill for now). I’d ideally like something between that range so I can get a good compromise between power and battery life, but if not I’m wondering which would be more power-effective. In other words, if the 160w draws twice the power, will it be twice as good?
I don’t know anything about power of MV bulbs (I just use piddly LED ones), but from a technical perspective - with the battery that you have, how long do you expect a 80W or 160W to last on the battery you already have? What is the capacity of the battery that you have?
How does that compare to the duration of your current set-up?
It may be that if you’re out for limited time you can afford to blast it with 160W, and not worry about run time. But I think it would help to know where you are starting from with the parts you already have.
The battery I currently have is 20ah. On the 20ah, the 80w (if my calculations are correct!) would last about 3 hours, probably less due to inefficiencies, and the 160w would last for half that at 1.5 hours.
This new battery (which I didn’t mention clearly in my post, so apologies) is 150ah, and would run the lights for 22.5 hours and 11.25 hours respectively.