I'm an industrial design student, so my question refers to a theoretical product design for a mobile projector. To start I built a "guerrilla projection" cart that utilizes a deep cycle battery, a 600w pure sine inverter and a 300w classroom projector. It works fine, and I can project for about 60-80 minutes. Now I'm trying to determine what it would take to reduce those three components into a single unit. The goal is to have it be as bright and lightweight as possible and run for about 2 hours. Imagine a pico projector on steroids.

I want to use a solid state light source that I estimate will run 200w. I did a ton of research on batteries and think I want to use a 100AH LiFeMnPO4 Prismatic 12v battery.

What I don't know is how the power supply for something like this would work. Do projectors' power supplies typically convert AC to DC? With the right inverter I can get whatever wattage I want from a lead acid battery, but can I get a 12v LiFeMnPO4 up to 200W without the inverter?

 

All projector's power supplies convert AC to DC.

I have an LG LED Minibeam 1080 HD projector, and it only takes about 100W while generating good brightness to a 100" screen.
It uses an external supply that generates 19Vdc @5.8A for power (110W max), so you likely could power most LED projectors directly from DC without needing a DC-AC inverter (but you likely will need a DC-DC converter to get the needed voltage from the battery.
The converter would be more efficient than using an AC inverter, which then is converted back to DC.

What's the current rating of the Li battery?

 

Thank you, that's exactly what I needed to know. I did some looking around and found a 12v step up to 24v 8A 200w DC to DC converter, which sounds like the solution.

Battery specs say max continuous discharge of 100 amps.

 

I did some looking around and found a 12v step up to 24v 8A 200w DC to DC converter, which sounds like the solution.

Only if the projector can operate from 24Vdc.