Power source mega w/ 4" tft

I am working on a project that will consist of the following: a 5v [fan](http://NOK 9.31 14%OFF | 2018 Mini Cooling Fan Heat Sink For Raspberry Pi 3/2/B+ 3.3V / 5V Model Computer High Quality Cooling Fan
AliExpress - Online Shopping for Popular Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles and More.), 4 [buttons](http://NOK 8.88 6%OFF | 20pcs/lot 8x8x5MM 4PIN G77 Conductive Silicone Soundless Tactile Tact Push Button Micro Switch Self-reset Free Shipping
AliExpress - Online Shopping for Popular Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles and More.), a [joystick](http://NOK 3.45 | For Arduino Dual-axis XY Joystick Module Higher Quality PS2 Joystick Control Lever Sensor KY-023 Rated 4.9 /5
AliExpress - Online Shopping for Popular Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles and More.), a [4" display](http://NOK 56.01 | New 1pcs 3.97 inch tft display st7793 driver for uno r3 2560 r3 240*400 resolution 240x400 tft screen
AliExpress - Online Shopping for Popular Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles and More.), and an [Arduino mega ](http://NOK 51.62 | 1pcs Mega 2560 R3 CH340G/ATmega2560-16AU MicroUSB. Compatible For Mega 2560 With Bootloader (Blue/Black) For Arduino
AliExpress - Online Shopping for Popular Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles and More.)

By the way, the fan is for cooling down the screen as it gets unpleasantly Warm during usage.

However, after ordering all the parts I realized a 9v volt battery will maybe only last a couple of hours of usage, and then be replaced, as the code the Arduino will be running will be up to 80-90% memory. As I have no idea how to start with rechargable batteries I thought, why not just buy a rechargable 9v battery and use that instead, but its abit pricey, and I would like something less space consuming as my project has to be compact. However, I would really appriciate using a rechargable battery as normal batteries are expensive where I live, and will make the project less "appealing". Also because when its out of power you can charge it instead of buying a new battery for $3.

In other words, how should I power my setup with a type of rechargable battery that doesnt explode in the users face after two charges, and lasts for 3 hours of usage++?

sumfuk:
I am working on a project that will consist of the following: a 5v [fan](http://NOK 9.31 14%OFF | 2018 Mini Cooling Fan Heat Sink For Raspberry Pi 3/2/B+ 3.3V / 5V Model Computer High Quality Cooling Fan
AliExpress - Online Shopping for Popular Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles and More.), 4 [buttons](http://NOK 8.88 6%OFF | 20pcs/lot 8x8x5MM 4PIN G77 Conductive Silicone Soundless Tactile Tact Push Button Micro Switch Self-reset Free Shipping
AliExpress - Online Shopping for Popular Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles and More.), a [joystick](http://NOK 3.45 | For Arduino Dual-axis XY Joystick Module Higher Quality PS2 Joystick Control Lever Sensor KY-023 Rated 4.9 /5
AliExpress - Online Shopping for Popular Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles and More.), a [4" display](http://NOK 56.01 | New 1pcs 3.97 inch tft display st7793 driver for uno r3 2560 r3 240*400 resolution 240x400 tft screen
AliExpress - Online Shopping for Popular Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles and More.), and an [Arduino mega ](http://NOK 51.62 | 1pcs Mega 2560 R3 CH340G/ATmega2560-16AU MicroUSB. Compatible For Mega 2560 With Bootloader (Blue/Black) For Arduino
AliExpress - Online Shopping for Popular Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles and More.)

By the way, the fan is for cooling down the screen as it gets unpleasantly Warm during usage.

However, after ordering all the parts I realized a 9v volt battery will maybe only last a couple of hours of usage, and then be replaced, as the code the Arduino will be running will be up to 80-90% memory. As I have no idea how to start with rechargable batteries I thought, why not just buy a rechargable 9v battery and use that instead, but its abit pricey, and I would like something less space consuming as my project has to be compact. However, I would really appriciate using a rechargable battery as normal batteries are expensive where I live, and will make the project less "appealing". Also because when its out of power you can charge it instead of buying a new battery for $3.

In other words, how should I power my setup with a type of rechargable battery that doesnt explode in the users face after two charges, and lasts for 3 hours of usage++?

You could use a lipo/lion battery with a control board attached.
There exists really nice boards that have bult-in protection (overdischarge, shortcurrent, undervoltage protection etc.), charging capability from a usb port and a buck converter to convert 3,7-4,2V from battery to a stable 5V efficently.

Here's an example of a DIY module: DIY LiPo Charge/Protect/5V Boost Circuit - YouTube

The links are broken and so I can't see the products, but I don't see normal that a screen heats up.

Speaking of experience, both of my 2.4" toucscreens "overheat" they become maybe 50°c on the surface. I can fix the links later today.

But thanks for the advice (:

display, a 5v fan using 0.20amps, an arduino mega, a joystick and four buttons. I cracked up one my my 12000mah powerbanks and planning on using that, but I'm making three so I still need advice for the two others :stuck_out_tongue: