When I was going for a 1000 watts I had intended to power it off 120volts. I’ve since changed my mind about that and decided portability will make it atleast a bit useful and more fun. As far as runtime goes I think I would be happy with 20 to 30mins. If I calculated it right a 4s Lipo 10000mah battery will run a 180 watt bulb for about 40mins.
400watts seems a little high. From the research I have done aluminum reflectors are not as durable to holding up in high heat as rhodium is and that is partly why most of the high wattage searchlights are using rhodium reflectors. I feel like if I stay around 200watts, the heat will be less of an issue.
I would would expect more like 20-30mins because you need take into account the ineffciency of each part of the electronics. The ballast might have 90% and the step up converter might have 80-90% again (I’m just guessing on the latter).
I don’t know about the cooling. Again you could ask polar_li on CPF. He made a 400W light . His reflector also has the AQ coating like yours.
I would add a tripod mount to the light. That will make it much more practical. Threads for a normal photo tripod should be enough. You can get very rigid tripods on Ebay if you search for older ones (I reccomend old Velbon Aluminium tripods).
Concerning the batteries:
Li-Pos only make sense if you get really cheap ones. They have a lower cycle count (life expectancy) compared to other types of betteries, really suck in the (<=5°C) cold in the winter (I don’t know how cold it gets where you live) and are more dangerous than other cells. For a more longterm solution I would think about getting a custom battery pack with 18650 or 21700 cells and a built-in protection and balancing circuit. I would use cheap Samsung 30Q cells. They have a high-capacity and work great in cold temps. Or maybe a hobby LiFePO4 pack.
Yeah I wasn’t thinking about inefficiencies so you probably are right about it realistically being 20-30mins. I may need to use a 15ah or 20ah since I’ll have to power the cooling fan/fans too and thats gonna cut into the runtime some more. Also I typed lipo but I meant lifepo LOL. Thinking about this one. Custom LFP 26650 Battery: 12.8V 19.8Ah (253 Wh, 30A rate ) rechargeable battery
Polari has an account here as he posted a couple of times in my 1000watt thread. I pm’d him both here and on CPF to ask him to lend his expertise if he don’t mind.
The tripod mount is a good idea. I’m still trying to come up with a suitable housing for the light. I’ve been thinking outside the box and I think a 3 drawer tool box like this would make a good host. Would have to get someone to weld a mount onto the bottom of it.
Well technically your were thinking inside the box :partying_face:
Just so you know: there are two types of UHP bulbs. The well known ones for projectors and also Osram Sirius HRI bulbs for moving heads. They use the same tech.
But it’s really weak and you won’t get any throw because of the very low luminance (maybe 1/100th). Also, there are better companies for COB LEDs. The brightest ones are made by Citizen, 70000 Lumens at 500W.
True but that will require a significantly larger power supply and cooling required for it would make it even larger. Given the size of that reflector would make an unweildly light even more unweildly.
I don’t think that matters too much. It’s too large and heavy to carry around much anyhow. I think it’s all about performance. Combining a huge COB LED with an electro-formed precision reflector is a waste. You can use a salad bowl coated with aluminum foil for that and it would probably focus good enough.
Yeah I don’t see these huge COBs making a lot of sense. I think it makes most sense to pair a high precision reflector to a high precision light source.
PolarLi got back with me! He really knows his stuff. Glad I contacted him as he gave me all the information I needed to get started building this light. The ballast PolarLi linked me too is 200w. So I’ve decided on what bulb I’m gonna use. Its the Osram P-VIP 240/0.8. Its the highest wattage bulb I could find with a 0.8mm arc length. Its has an operating wattage range from 190w-240w. 200watts is on the low end for this bulb but this bulb allows me to switch to a higher wattage ballast whenever I want to without having to go through the process of seperating another bulb from the original reflector, mounting, and then aiming all over again.
So the ballast has been ordered. I also am going to get my brother to custom make me an aluminum housing for the light. I was gonna use the toolbox but the weight on all of them that I could find that were the perfect size was just ridiculous LOL.
Will do. Since I got my answer on what I should do with this reflector I will probably start another build thread. Will post all the future updates there. Thanks for all your help guys, particularly you The_Driver!
Tax season hit hard this year haha! I’ve got the ballast, a bulb (not the one I really want to use), and all the cooling fans. Still trying to collect the rest of the parts but got to pay Uncle Sam first. Also need to get someone to build me a custom housing. My original plan of using a tool box as a host is just gonna be too heavy. Needs to be made of aluminum so itll be a lot lighter.
