Use of External Battery Power Pack

[Android_EPL]

Would using an external battery pack all the time be hard on the main Android Battery?

 

[tommo47]

It is generally accepted that charging a battery and using the device at the same time is not good practice. Some activities result in fairly heavy battery drain and there is a risk of overheating the battery which is most certainly harmful.

I carry an external battery pack quite often, particularly when out hill-walking, but will keep a close check of battery charge state and only connect the charger when necessary, making as little use of the device as possible at that time.

 

[lvt]

It's also hard for the battery pack too as its circuit has to convert 3.7V/3.8V to 5V, resulting some heat.

 

[dontpanicbobby]

Yes and no...
Unplug when you hit 100% and let it deplete to about 30% before you plug back in.
Yes: Always charging damages both
No: You'll have years of use when unplug your charger.

 

[svim]

Would using an external battery pack all the time be hard on the main Android Battery?

Using your mobile device with an external battery connected to it all the time creates a lot of conflicting situations. There's a big difference in how your device is working when running off its internal battery vs. when you have an external battery connected to it. The former is a typical state, the latter is in charging mode. Here's some good reading on what's going on:
https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
also, since that external battery will be using your USB port (microUSB or Type-C):
https://batteryuniversity.com/learn/article/charging_from_a_usb_port
Not knowing just which model you have or any other relevant details to your question, it's hard to be more definitive but generally if the battery in your device has failed and it has a user-replaceable one you'd be better off just replacing the internal battery than using an external one. Again, depending on what model a non user-replaceable battery 'might' still be readily replaceable, but that's very, very dependent on what model as some are relatively easy to get to, some require a complete tear-down and are secured in place with lots of glues and adhesives.
But if replacing the battery isn't an option, and you do have to rely on an external battery as a stop gap measure, there are some phone cases that have integral batteries. But at that point, instead of buying one of those you might want to devote those funds to just upgrading to a new(er) phone. Just weigh your options.

 

[Ashok Kumar Narwariya]

Using your mobile device with an external battery connected to it all the time creates a lot of conflicting situations. There's a big difference in how your device is working when running off its internal battery vs. when you have an external battery connected to it. The former is a typical state, the latter is in charging mode. Here's some good reading on what's going on:
https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
also, since that external battery will be using your USB port (microUSB or Type-C):
https://batteryuniversity.com/learn/article/charging_from_a_usb_port
Not knowing just which model you have or any other relevant details to your question, it's hard to be more definitive but generally if the battery in your device has failed and it has a user-replaceable one you'd be better off just replacing the internal battery than using an external one. Again, depending on what model a non user-replaceable battery 'might' still be readily replaceable, but that's very, very dependent on what model as some are relatively easy to get to, some require a complete tear-down and are secured in place with lots of glues and adhesives.
But if replacing the battery isn't an option, and you do have to rely on an external battery as a stop gap measure, there are some phone cases that have integral batteries. But at that point, instead of buying one of those you might want to devote those funds to just upgrading to a new(er) phone. Just weigh your options.

My battery very fast discharge please help me

 

[svim]

My battery very fast discharge please help me

Is this a one-time issue or a problem that's happening all the time lately? Just restarting your phone might help if the former. But if it's a persistent problem, there could be any number of things that are causing faster battery discharging. If you look in your Settings >> Battery menu does it show any app that might be a problem?
Your profile states you have a Galaxy Grand Max, is that still current info?
https://www.gsmarena.com/samsung_galaxy_grand_max-6905.php
That model does come with a user-replaceable battery so at least if it's just a matter where the battery is starting to fail you can easily replace it.