Nexus 7 2013 LTE Tablet in Lexus IS 200: Power Supply, Step Down Converter, Delay Relay, USB Hub

Hello,

I'm preparing to mount the Nexus 7 LTE 2013 tablet in the Lexus IS 200 car.
I have already collected most of the parts but I have a big dilemma about connecting the power supply to the car. Namely, there are 2 variants:

Variant 1:

- removing the battery from the tablet due to winter / summer weather conditions and connecting it via a step down converter e.g. to a battery
for this I would like to mount a delay relay module for e.g. 30 minutes after switching off the ignition so that the tablet does not turn off after each key removal when refueling. Can any fuse be used for this? Will the converter 12v> 5v e.g. 3A embrace it?
- For this I would like to mount a USB HUB and a rear view camera and possibly a place for some other devices. From what I read on the internet, USB HUB may not be able to power from the tablet via the Y OTG cable and therefore I have another dilemma whether to lead a separate power source to it

Variant 2:

-Leave the battery and stock up on two USB chargers with some specific parameters to do so charging the tablet and a separate power supply from the second USB HUB charger. The only question is whether the tablet's power consumption will not be so great that the charger can keep charging it,

I would prefer to use the first option. Attached I add a diagram that I have drawn more or less. I am not an advanced electrician, therefore I ask for advice or any corrections. Thank you very much in advance

kwasikowsky wrote:

- removing the battery from the tablet due to winter / summer weather conditions and connecting it via a step down converter e.g. to a battery

Not wise - you play with physics.

kwasikowsky wrote:

for this i would like to mount a delay relay module for e.g. 30 minutes

I am curious about this device - did you find such a thing?

A few people have already done so during the assembly and everyone is happy, moreover there is a special kernel for Android equipped just adapted to this no battery mod.

YT link: https://www.youtube.com/watch?v=9N2Bh4fI8Bo&t=15s

Link to this relay: http://allegro.pl/modrl01-usb-time-delay-modul-czasowy-przekaznik-i6950786665.html

Hello, I have been playing with the nexus in the car for some time, I have a few problems with charging

Added after 6 [minutes]:

Everything works great for me, but I still have a problem with power loss. It happens that, for example, 24 times 1proc battery is depleted and it happens that and 40%, something wakes the tablet and eats the batteries

Try to configure the tasker application. Do you use a USB charger? maybe she is too weak

I didn't receive an email from you. I use a regulated power supply, I have a voltage of 5.5 V. It only charges well with a voltage drop problem. I have the Nexus 2017 LTE version with SIM card and internet. Android 6.0 root, Timur kernel kernel,

conradk wrote:

I use a regulated power supply, I have a voltage of 5.5 V. It only charges well with a voltage drop problem.

Voltage, voltage. What about the electricity?

I have not expressed myself well, the tablet in sleep mode discharges too quickly, something wakes it up and eats its batteries,

Added after 11 [minutes]:

For now, after numerous attempts to install various androids taskers etc. after 10 hours in sleep mode, further 100 percent battery. I installed the Gapps MINI package, uninstalled redundant system applications like calendar, calculator, google photos. It also turned out that Wifi eats batteries very much, you need to turn off scanning in the location settings. For now, testing at home. I also read that the reason for the fast discharge can be a faulty charger or power supply when starting the ignition the tablet gets a kick and this can also be the reason. You could put a switch in front of the power supply

Hello, I finished the nexus a 7 project in audi a3. The tablet is pulled out of the tray. The music flies through otg to processed to give behringer and then to the 4 channel amplifier in the trunk. Everything good. I made a separate switch on the charger because turning off the ignition as for a moment I got out of the car irritated me. The only problem is not a small problem and here I am asking for help Regards turning on the power on the charger and hence the tablet does not activate so give only a disconnection for a fraction of a second and reactivate it again. It is like this every time it stands above 7 minutes. You have to attach it twice. Any ideas?

Hello and have you managed with this power supply ??