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I recently put together a portable RetroPie project with an LCD from an old laptop, it runs fine off an old ps2 power supply drawing around 1A.

However, I decided to try running it off 8 LiPo cells (18650) I had lying around. I put the 8 cells in parallel, and connected them to a 6A DC to DC step up converter setting it to 12v.

The red LED on the driver board lit up telling me the board was receiving power, but when I hit the power button the LED turned green, which indicates that it is turning on, then backlight flickered and the whole thing reset, the LED also went back to red, this will repeat as many times as I push the power button.

I am assuming that the culprit is the CCFL needing more current than the DC to DC converter can provide, however the specs say that the board needs at most 2.5A so I am uncertain.

If anyone knows what I can do to get this working, any help would be greatly appreciated.

DC to DC converter: http://a.co/aEGWhaY LCD Driver: http://a.co/b3kLdwH

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  • \$\begingroup\$ "connected them to a 6A DC to DC step up converter" - No, it's only a claimed 6A boost converter. I saw a YouTube video where an engineer used an electronic load, meters and (I think) a scope, to test another similar cheap boost converter and found it didn't meet even close to its claimed specs :-( That is just to show you can't believe specs on cheap converters :-( Proper diagnosis of your design would need V & I measurements during carefully designed tests, and ideally things like electronic load, scope etc. Or you can guess and try possible solutions, but with no guarantee of success. \$\endgroup\$ – SamGibson Jan 24 '17 at 23:08
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The converter (or batteries) can't keep up with the in rush current, dipping down too much or is too noisy for the driver. Try adding a 1000 uF capacitor to the power input of the Driver.

Other option is to put the cells in series and regulate them down to 12V instead. Or use 3 in series with a regulator. The driver likely still works at less than 12V input.

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  • \$\begingroup\$ I have a 16v 2200uF cap, will that work? if so do I put it in series with the driver board or in parallel? \$\endgroup\$ – Ryan Blue Jan 24 '17 at 22:57
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    \$\begingroup\$ You rarely, if ever, put a DC cap in series with anything. \$\endgroup\$ – David Schwartz Jan 24 '17 at 23:09
  • \$\begingroup\$ @ryanblue in parallel as close to the board as possible. \$\endgroup\$ – Passerby Jan 24 '17 at 23:17
  • \$\begingroup\$ I put the cap in parallel as close to the board as possible which increased the duration of the backlight flicker. but it still wont stay on. \$\endgroup\$ – Ryan Blue Jan 24 '17 at 23:35
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    \$\begingroup\$ Then the converter or batteries are insuficiente. It may not be able to boost to 12V and X amps from 3.6V, or faulty, or counterfeit. Or the batteries arn't good, if they are ebay counterfeits or pulled from a dead pack. Try three in series and see if that works directly. Then analyze from there. \$\endgroup\$ – Passerby Jan 24 '17 at 23:39

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