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mobile battery for pi and monitor help

Former Member

i been working on my own mobile pi. i got the pi side of things done but i have 2 problems left. 1st one is the poweing the monitor.

Amazon.com : 7 Inch Tft Color Lcd Car Rear View Camera Monitor Support Rotating The Screen And 2 Av Inputs : Vehicle Ove…

i been told it can runs 12V 500mA, the battery i want is Tenergy Li-Ion 18650 11.1V 7800mAh. i also like to have a solar charger for it

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  • The car uses "12V" nominal. But that means that you will see up to 14.8V on the voltage rail during fast-charging. When the car is turned off or not charging the voltage might be as low as 12V, but seldomly lower. (when starting the car, the voltage may drop as low as 8V, but most accessories are normally disconnected at that time).

     

    With a full 11.1V battery you will be at 12.6V, nicely in the 12.0 - 14.8V range that a car-accessory should expect. But when the battery drains, you might want continue to use it down to about 9V. On the other hand, if the monitor keeps on working down to 10.5 or 10.8V then you're in business. But it depends a lot on how the screen is built.

     

    A friend has a display that has a DCDC converter that converts 7V - 15V down to 5V and then only uses that. So his would work just great on a 3S LIPO. (He actually had 5V available but no 12V, so he made a "5V power input" on his screen, bypassing the regulator on the board.).

     

    I'd say: try it. As the backup-plan, buy a DCDC stepdown (buck) converter and a 4S battery.

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  • The car uses "12V" nominal. But that means that you will see up to 14.8V on the voltage rail during fast-charging. When the car is turned off or not charging the voltage might be as low as 12V, but seldomly lower. (when starting the car, the voltage may drop as low as 8V, but most accessories are normally disconnected at that time).

     

    With a full 11.1V battery you will be at 12.6V, nicely in the 12.0 - 14.8V range that a car-accessory should expect. But when the battery drains, you might want continue to use it down to about 9V. On the other hand, if the monitor keeps on working down to 10.5 or 10.8V then you're in business. But it depends a lot on how the screen is built.

     

    A friend has a display that has a DCDC converter that converts 7V - 15V down to 5V and then only uses that. So his would work just great on a 3S LIPO. (He actually had 5V available but no 12V, so he made a "5V power input" on his screen, bypassing the regulator on the board.).

     

    I'd say: try it. As the backup-plan, buy a DCDC stepdown (buck) converter and a 4S battery.

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