yellow bolt icon appears with sufficient power supply

[Jalebi]

The power adapter I'm using an adapter which outputs DC 5V,2A and I'm using a usb mouse (500mA) and a USB keyboard with HDMI to VGA adapter.
Should I change my power adapter? Samsung charger would work fine for a long run?

Some I picked
https://www.crazypi.com/Raspberry-Pi-2-Power-Adapter

[jamesh]

Try changing the power cable first. That is often a source of power problems.

[LTolledo]

You using that power supply unit (PSU) on a Raspberry Pi 2B? Then it should be OK.

If you use that on a Raspberry Pi 3B or Raspberry Pi 3B+, that is expected (and no buts about it), as the minimum recommended PSU rating is 5V 2.5A with thick cables, and not some phone's charger...

[jamesh]

You using that power supply unit (PSU) on a Raspberry Pi 2B? Then it should be OK.

If you use that on a Raspberry Pi 3B or Raspberry Pi 3B+, that is expected (and no buts about it), as the minimum recommended PSU rating is 5V 2.5A with thick cables, and not some phone's charger...

There are always buts. If you don't have much plugged in to the USB ports, you can get away with a lower output PS. I can use a 3B using my Motorola G4 charger which is 1.6A, but its a very good charger with thick cables.

But it really is much easier just to get an official power supply.

[jahboater]

Here is the spec for the "official" PSU mentioned above:

https://docs-emea.rs-online.com/webdocs ... 4ba6b1.pdf

Firstly the cable is a very thick 18AWG, and secondly the cable is fixed, so the rated supply voltage is at the plug (e.g. the Pi end), not at the output from the adapter.

[LTolledo]

It's either it runs properly or not. Take your pick. There is nothing in between.

[jamesh]

It's either it runs properly or not. Take your pick. There is nothing in between.

Well, there is runs properly until you plug in a USB device that takes a lot of power.

Horses for courses.

[LTolledo]

Well, there is runs properly until you plug in a USB device that takes a lot of power.

I rest my case

[jamesh]

Well, there is runs properly until you plug in a USB device that takes a lot of power.

I rest my case

Not sure what the case is. The point is, if you don't have high requirements on your USB devices, you can get away with lower powered supplies.

[HawaiianPi]

The power adapter I'm using an adapter which outputs DC 5V,2A

And you know this how? Have you actually verified that with a load test, or are you just taking the manufacturer's word for it.

I have a "5V/2.4A" phone charger that dips well below 5V at only a 1A load. It still charges my phone fine (most phones only need a little over 4.2V to charge), but it's a lousy Raspberry Pi power supply.

and I'm using a usb mouse (500mA)

Half an amp for a mouse?

and a USB keyboard with HDMI to VGA adapter.
Should I change my power adapter? Samsung charger would work fine for a long run?

Some I picked
https://www.crazypi.com/Raspberry-Pi-2-Power-Adapter

While some phone chargers might work fine, you will never know until you load test one, so it's best to avoid chargers and get a proper power supply. Power supplies that have a separate USB cable introduce another variable (many standard micro USB cables can't deliver the current needed), and additional connector losses to the system, so a nice, fat built in power cable often works better.

The official Raspberry Pi universal power supply is highly recommended here on the forums because it works, and works well. It's rated for 5.1V at up to 2.5A and has a built in power cable with thick 18 gauge wires. Click the picture below for more info.

[Imperf3kt]

It's either it runs properly or not. Take your pick. There is nothing in between.

Well, there is runs properly until you plug in a USB device that takes a lot of power.

Horses for courses.

Very much agree with this.
In some of my testing while building my own power supply for my Pi3b, I found that I could power my Pi3b, a 5" touchscreen, a wireless mouse, a wireless keyboard and additionally run a stress test on three cores all off ~850mA
Stress testing a fourth core or plugging in any other USB devices, pushed the power supply into unstable territory - its limit was only 1Amp after all.
I do however, still recommend the official power supply, its a great little supply and costs less than alternatives that don't work as well!

[Jalebi]

Thanks to everyone!!! Raspberry community is very helpful. Although I haven't seen that bolt icon since that time , I ordered the official power supply as suggested by some senior members here. Thank you guys.