Turn on phone without using any battery + can I put a custom ROM on it

[TukangUsapEmenq]

Well, I got myself a old Samsung Galaxy Star Plus (S-7262), which, to be honest, a really painful smartphone (and rather expensive, but Samsung still really dominates the market at the time anyway) to use even from the first time using it.

 

Now, it's laying on my drawer, doing nothing. What I wanna do is using that phone as a fixed little display for a Home Assistant UI, and I'll probably make a enclosure for that. I did watch a lot of videos, and unfortunately a lot of them are... Ridiculous, enough.

 

Any of you guys actually ever did this? Yes, (refurbished, probably fake) batteries are actually cheapo for this one particular phone, but since I'll plugging this thing like 24/7, I rather to not getting those risky things anyway (last time I bought a overpriced refurbished battery, it died, not even reaching a year).

 

And if this thing's still alive, I wonder if this phone can use a custom (really lightweight) ROM, since TouchWiz on this phone really kills me slowly (been using this phone for 2 years before replacing it).

[Bombastinator]

So if I’m understanding this right you’ve got this old phone you want to turn into what is effectively a pi or a beaglebone with a screen and use it to run some sort of software.

 

I can help perhaps a bit with step one which would be rooting the phone.

 

there is a video on jailbreaking that phone here

Once the phone is rooted other things can be done.  I don’t even know what a “home assistant UI” is though so I’d be of little help.

[TukangUsapEmenq]

4 hours ago, Bombastinator said:

So if I’m understanding this right you’ve got this old phone you want to turn into what is effectively a pi or a beaglebone with a screen and use it to run some sort of software.

 

I can help perhaps a bit with step one which would be rooting the phone.

 

there is a video on jailbreaking that phone here

Once the phone is rooted other things can be done.  I don’t even know what a “home assistant UI” is though so I’d be of little help.

Actually, I'm only using it as a display for this dashboard, connect the phone to a wireless router (without internet) and using a Raspberry Pi as a server. But, somehow....

4 hours ago, Bombastinator said:

you want to turn into what is effectively a pi or a beaglebone with a screen and use it to run some sort of software.

This is actually possible to at least using the phone as a "Raspberry Pi"? I've never heard of a phone becoming a little server for home automation, for real. If this actually possible, tho, might saving me some money for not buying a Pi lol

[Bombastinator]

1 minute ago, dhannemon13 said:

Actually, I'm only using it as a display for this dashboard, connect the phone to a wireless router (without internet) and using a Raspberry Pi as a server. But, somehow....

This is actually possible to at least using the phone as a "Raspberry Pi"? I've never heard of a phone becoming a little server for home automation, for real. If this actually possible, tho, might saving me some money for not buying a Pi lol

I don’t know that it is.  It’s got a lot of the required hardware.  It would have to be programmed though.   It would normally be a REALLY inefficient way to do things as you want to use a $250 machine to do the job of a $25 one. 

[TukangUsapEmenq]

46 minutes ago, Bombastinator said:

I don’t know that it is.  It’s got a lot of the required hardware.  It would have to be programmed though.   It would normally be a REALLY inefficient way to do things as you want to use a $250 machine to do the job of a $25 one. 

Well, for the sake of reducing complexity for mere $16 (for an used Pi 3 B+), anyway. Let's skip of that tinkering lol

 

The real question, still, is it good for just connect the battery terminals to a step-down 3.8V 3A (the phone itself rated at 1.5A, more amps for at least more breathable room for the phone, and less heat produced) power supply?

[Bombastinator]

7 minutes ago, dhannemon13 said:

Well, for the sake of reducing complexity for mere $16 (for an used Pi 3 B+), anyway. Let's skip of that tinkering lol

 

The real question, still, is it good for just connect the battery terminals to a step-down 3.8V 3A (the phone itself rated at 1.5A, more amps for at least more breathable room for the phone, and less heat produced) power supply?

Lithium batteries are a bit like balloons. They generally start around 4.25v and give up the ghost around 3.0 generally.  I don’t know the amperage but is suspect that you don’t even have to hit 3.8v on the head to make it go.  You will not want to plug the thing in at the USB  port and do that at the same time though.

[TukangUsapEmenq]

8 minutes ago, Bombastinator said:

Lithium batteries are a bit like balloons. They generally start around 4.25v and give up the ghost around 3.0 generally.  I don’t know the amperage but is suspect that you don’t even have to hit 3.8v on the head to make it go.  You will not want to plug the thing in at the USB  port and do that at the same time though.

Ah, yes. I forgot the fact that batteries would be go for that voltage curve. But since on the phone itself rated at 3.8V -- 1500 mA (saw it on the sticker on the backside), I think it would be fine to run at 4-4.2V ish (assuming some voltage loss while on load) anyway. Some videos on YouTube even using the charger of the phone itself. I'd pity on the device itself running on almost 5V and only at 1 A tbh

 

So, yeah. I think I would just get the step-down converter later on. This made my mind for finally lol

8 minutes ago, Bombastinator said:

You will not want to plug the thing in at the USB  port and do that at the same time though.

This is exactly what I saw on here. I hardly can't hold my 'why in the f this guy' for that lol

[Bombastinator]

32 minutes ago, dhannemon13 said:

Ah, yes. I forgot the fact that batteries would be go for that voltage curve. But since on the phone itself rated at 3.8V -- 1500 mA (saw it on the sticker on the backside), I think it would be fine to run at 4-4.2V ish (assuming some voltage loss while on load) anyway. Some videos on YouTube even using the charger of the phone itself. I'd pity on the device itself running on almost 5V and only at 1 A tbh

 

So, yeah. I think I would just get the step-down converter later on. This made my mind for finally lol

This is exactly what I saw on here. I hardly can't hold my 'why in the f this guy' for that lol

He apparently removed the battery but saved the battery controller board.  My WTF?!?! Moment was watching him throw a gigantic LiPo bag battery with no controller in regular trash. I really hope no one burned to death. There’s a reason those things are hazardous waste.

 

the deal with his thing is the way his tablet is rigged it showed “battery full” so the cable wasn’t trying to push power into the the PSU. That might actually be That battery board doing it’s job.  One of the things LiPo batteries should never ever have done to them is be overcharged. Undercharged is bad too but a lot less bad.  Not boom! fire! bad.  He either knew exactly what he was doing and trusted the electronics or he got flat out lucky.  Not sure.  The whole throw-the-brick-of-lithium-electrolyte-in-the-trash thing says “lucky” to me. Might still be know-what-he-is-doing.  I don’t see how that battery doesn’t turn into an incendiary grenade when the garbage truck crusher snaps that thing in half though.