Make the led glow at certain voltage

Reloadron

Joined Jan 15, 2015
7,891
My current ohone is a Samsung Galaxy 7 using Android. It has a light which is red during charging and green when 100% charged, Also plainly visible is the state of the charge, There must be a dozen apps out there to monitor battery level. Most of these phones include apps telling you anything you could want to know about the battery and power consumption.

Ron
 

DickCappels

Joined Aug 21, 2008
10,661
If you want to monitor the battery charging status from a distance enable Find My Iphone. You can then use a web browser on Apple's site to see the charge level and whether the phone is charging or not.

I suppose some resourceful person could figure out a way to control an LED based on information from the browser.
 
Old Android phone:
Usb connector:
1) blinks (crys) when it wants to be fed
2) Steady when it's charging
3) Off when it's fully charged.

Green only. I like the blinking aspect,

It won't charge and tether forever like my old Razer did. This one will deplete the battery first.
 

Thread Starter

ekremgusani

Joined Mar 20, 2011
157
Then write an app that reads the charge status and displays it on the screen big enough to see from a distance. Or that changes the color of the screen as it charges. Or that lights up the screen only after it has reached some threshold.
That would be great if i know how to do it
 

ian field

Joined Oct 27, 2012
6,536
How is TS going to get access to a battery sealed inside a cell phone?
Never seen one of those - all mine; the back unclips and you can pull the battery out.

my phone doesn't even display; "charging", so I rotate 2 batteries through a commercial universal charger. Then I know its charged when the indicator changes from red to green.
 

spinnaker

Joined Oct 29, 2009
7,830
Never seen one of those - all mine; the back unclips and you can pull the battery out.

my phone doesn't even display; "charging", so I rotate 2 batteries through a commercial universal charger. Then I know its charged when the indicator changes from red to green.

You need to join the 21st century like me. My battery comes out too but the youngsters today have these new fangled phones where the battery is sealed inside. They tell me you can get on the interweb and everything. ;)
 

David Ward

Joined Dec 11, 2016
1
I'm building a USB DCP to charge phones from a 12-16V source for a university project. I thought about monitoring charging status by using a shunt resistor to determine how much current the phone was drawing and switching an led to show the status, but it was primarily to check over current. I reckon it is possible with a shunt and comparator, but realised it was pretty pointless and just not worth the hassle.
 

ian field

Joined Oct 27, 2012
6,536
You need to join the 21st century like me. My battery comes out too but the youngsters today have these new fangled phones where the battery is sealed inside. They tell me you can get on the interweb and everything. ;)
I've got a highly technical smart phone - that also has a removable battery.
 

Thread Starter

ekremgusani

Joined Mar 20, 2011
157
How can i ad led to usb cable so the led can lite when phone is fully charged or there would be even bettter if i can use rgb led so it can lite red for low, blue for half charged and green for fully charged phone?
I would appreciate if you reply with schematic so i try it straight away!
Thanks!
 

Sensacell

Joined Jun 19, 2012
3,785
One word- "No"

Modern cellphone batteries and charging systems are complex, you cannot derive the state of charge without some complex software and circuits that communicate with the charging system.
 

crutschow

Joined Mar 14, 2008
38,529
You can't monitor the voltage, since that's not a reliable indicator of the battery charge state.
But assuming the smart charger reduces the charge current when the battery reaches the fully charged state, you could monitor th current and turn the LED on when the current drops to a specific (experimentally determined) value.

I doubt there's an easy way to determine the half-charged point.
 
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