My Haier HLT10 LCD display has a 120VAC wall wart that indicates 9V at 2 amps and the TV itself says it uses 18W. Now I've gotten mixed messages from my web searches, but what I'd like to do with this display is power it without its AC adapter directly from a 3S LiPo (which is, of course, effectively 12V DC). Here's my question: is this safe? I've heard from people that Haier sell a 12V adapter (for car cigarette lighters) that's a straight-through cord, so my assumption is that the TV will step it down. The internal batteries are apparently a 2S LiPo, but there's speculation that there's some kind of circuitry in between. Does anybody use one of these displays? And if so, how are you powering it? I'm not sure my display's internal batteries are still good as it doesn't hold much of a charge, although it works just fine with external power. Thanks!
I'm not sure I know the answer to "is it safe" (except in hindsight), Steve. However, what I'm doing is use an LiFePO4 12.8v battery through a Watts-Up with a Hotbox breakout that has five XLR4F's. This gives me the 12v that either the SmallHD or the Haier needs -- it also powers the FPV Lawmate 1.2Ghz and Camera Op Passport RXs. If I need 5 v, I've made up some XL4M -> Cigarette lighter or XLR4M -> Recom/BEC leads so that I can drop the voltage down. You can usually take apart those auto adapters pretty easily and see if they've got any DC/DC converters in them, but I suspect you're right about the TV having a DC/DC regulator in it. Andy.
Thanks for all that. Seems very complicated....lots of connections! And why a LiFePO4 and not one of the (MANY) LiPo batteries I have sitting around?
Well, the Watts-Up monitors the Amp/Hours consumed so I don't lose FPV downlink. The Hotbox is just a convenient way of distributing power to the various devices and standardizes on XLR4's. The LiFePO4 is in a gel-cell sized container so it's a little more robust and I fret a little bit less about the fire risk. Also it has built-in circuitry to avoid overcharging and, more importantly, over-discharging. Oh...and I had the setup for on-location video shooting before I got "into" copters. Andy.