I started making a "case-top" as I like to call it. Raspberry pi 3-based laptop. Took an electrician's case emptied it and started putting the components in.
https://www.sparkfun.com/products/12711 connected to 4 18650 3400mah protected batteries which are in parallel, and each one has a TP-4056 JUST to avoid explosions. An XL6009 takes the power from the charger and drops it on the pi @ 5V, and another XL6009 takes the the power from the charger and drops it on the LCD CONTROLLER @ 12V.
The afformentioned board is similar to this http://www.ebay.com/itm/NJYTouch-M-NT68676-2A-HDMI-DVI-VGA-AUDIO-LCD-Controller-Board-for-LTN170X2-L0-/282420095187.
When I use the 12V 4A it requires instead of the batteries it works perfectly. Power, sound, light. The screen works like a treat. But when I try to power it from the batteries, one small LED on the button board flashes once and I get nothing. No power, no light, no nothing.
I know the XL6009 WORKS, because I did measure the out volts and i do get 12.1V constant on the plug, not on the board. So both the board and the cable/plug I have soldered have power.
What am I missing, (apart from a brain)?
please notify me if it is not readable. Thank you😊
The batteries are these http://www.keeppower.com.cn/products_detail.php?id=375
and these are the step up modules http://www.gearbest.com/other-accessories/pp_227265.html