Why does the battery take ages to charge?

[IBNobody]

So I have been using my extra Pre charger as my mobile charger and after reading this very informative post (thank you everyone!) I just have one clarification question: is it okay to charge the Epic with the Pre charger or is that going to cause bad battery wear and tear?

It will not hurt your phone to charge it with your Pre charger, provided that your Pre charger is in good condition.

 

[taylormah]

IBNobody, The link you provided in your XDA post to appbrain for some battery app is broken. Can you please post the link here or share the name of the app which graphs the battery draw??

Also, what is your view about this thread/post about a Captivate charger? The guy says his 1amp charger is helping in charging the battery "more". His 100% battery level stays longer. Any ideas?

 

[IBNobody]

IBNobody, The link you provided in your XDA post to appbrain for some battery app is broken. Can you please post the link here or share the name of the app which graphs the battery draw??

Also, what is your view about this thread/post about a Captivate charger? The guy says his 1amp charger is helping in charging the battery "more". His 100% battery level stays longer. Any ideas?

The battery graph app is called "battery graph".

As to the post, I would suspect that his software malfunctioned (stuck at 100%), he has a hardware defect (better battery?), or he was reading the battery bar graph which stays "full" up to about 85%.

If you use battery graph, you'll see that the phone repeatedly tops itself off at regular intervals. It will charge to 100%, drop to 97%, then charge back to 100%.

If you want more battery knowledge, check out this link:
Charging lithium-ion batteries

 

[Aero]

Have you actually measured the current the phone draws? My understanding was that the phone only draws 600ma when D+/D- are shorted and 380 when they are not- thanks in advance

Yes I measured it with a set of digital probe and an open micro male to female I have to check actual amperage pulled. You have six connectors which can be polled on a USB micro (1,2,x,3,5,collar). With a 2-x (aka 2-5) short it pulls one amp. with a 2-3 short it pulls a bit under 700. with no short it is pulling 400.

Here is the FAQ I wrote up on the subject on XDA:
[FAQ][10/11/10] Samsung Epic USB/Wall/Charger FAQ - xda-developers

Incorrect and if you play around with the various combination shorting the six (5+1) connectors you will see

 

[IBNobody]

Yes I measured it with a set of digital probe and an open micro male to female I have to check actual amperage pulled. You have six connectors which can be polled on a USB micro (1,2,x,3,5,collar). With a 2-x (aka 2-5) short it pulls one amp. with a 2-3 short it pulls a bit under 700. with no short it is pulling 400.

Incorrect and if you play around with the various combination shorting the six (5+1) connectors you will see

It's worth a shot to try - I'll independently corroborate your values and post back.

Edit: I even have a phone I can blow up.

 

[Aero]

It's worth a shot to try - I'll independently corroborate your values and post back.
Edit: I even have a phone I can blow up.

cool. just check your final voltage as well (make sure you are seeing >5 as opposed to 3.5 or so.
you especially want to check with a 2-x short both brought to 4 with 220 K Ohms.

Reference read on pins useint standard which is l to r
1 2 3 x 4 (data at 2,3, ie white and green) voltage at 1, ground at 4 and x as "ident pin" used to control used charging current. Check your final voltage on the x pin to make sure it is about 1.5 volts which seems to enable actual fast charging as opposed to the medium charging.

 

[jimmyz]

Yes I measured it with a set of digital probe and an open micro male to female I have to check actual amperage pulled. You have six connectors which can be polled on a USB micro (1,2,x,3,5,collar). With a 2-x (aka 2-5) short it pulls one amp. with a 2-3 short it pulls a bit under 700. with no short it is pulling 400.

Incorrect and if you play around with the various combination shorting the six (5+1) connectors you will see

This is very informative- thanks. Can you recommend a 1a charger/cable combination which will allow the epic to draw 1amp?

 

[IBNobody]

No luck, I'm afraid. I tried my bare microUSB connector that only had V+/- connected back to the source. I soldered test leads to the 5 terminals.

I tried every combination with D+, D-, Ident, and GND, but I was only able to pull 600mA.

Oddly, the combination you suggested (with a 220k resistor or a 22k) yielded a behavior yet unseen - the phone would not detect the charge setup at all.

Tomorrow, I'll rig up a more professional testing harness and go through all possible values.

Who makes the charger that you have? Is it an actual 5-wire or 5-wire-plus-shield cable, or is the Ident pin shorted inside the plug?

 

[IBNobody]

Still no luck...

Ignore my wire colors because I didn't have black or green.

I did see that pulling the ID line down triggered the 600mA charge mode.

It did behave curiously, as I was able to get it into a mode which drew 10mA.

What I can do next is hook up some trimpots to D+, D-, and ID and adjust their voltages between VCC and GND.

If you can provide me with any more data, I would appreciate it. My time I have access to my sacrificial Epic is limited, and I will not be attempting this on my good Epic.

	[b]Pin	Color	Line[/b]
	1	Red	V+				
	2	Orange	D-				
	3	White	D+				
	4	Yellow	ID				
	5	Purple	GND				
						
[B]Color	Color	Color	Current	Line	Line	Line[/B]
	Orange	White	600	D-	D+	
	Orange	Yellow	600	D-	ID	
	Yellow	White	600	ID	D+	
						
	Orange	Purple	380	D-	GND	
	White	Purple	380	D+	GND	
	Yellow	Purple	600	ID	GND	
						
	Orange	Purple	380	D-	GND+1k	
	White	Purple	380	D+	GND+1k	
	Yellow	Purple	600	ID	GND+1k	
						
	Orange	Purple	380	D-	GND+10k	
	White	Purple	380	D+	GND+10k	
	Yellow	Purple	0	ID	GND+10k	
						
	Orange	Purple	380	D-	GND+100k	
	White	Purple	380	D+	GND+100k	
	Yellow	Purple	10	ID	GND+100k	
						
	Orange	Purple	380	D-	GND+200k	
	White	Purple	380	D+	GND+200k	
	Yellow	Purple	380	ID	GND+200k	
						
						
Orange	White	Purple	380	D-	D+	GND
Orange	Yellow	Purple	600	D-	ID	GND
Yellow	White	Purple	600	ID	D+	GND
						
Orange	White	Purple	600	D-	D+	GND+1k
Orange	Yellow	Purple	600	D-	ID	GND+1k
Yellow	White	Purple	600	ID	D+	GND+1k
						
Orange	White	Purple	600	D-	D+	GND+10k
Orange	Yellow	Purple	600	D-	ID	GND+10k
Yellow	White	Purple	600	ID	D+	GND+10k
						
Orange	White	Purple	600	D-	D+	GND+100k
Orange	Yellow	Purple	600	D-	ID	GND+100k
Yellow	White	Purple	600	ID	D+	GND+100k
						
Orange	White	Purple	600	D-	D+	GND+200k
Orange	Yellow	Purple	600	D-	ID	GND+200k
Yellow	White	Purple	600	ID	D+	GND+200k

EDIT: I will be getting access to an OEM Pre charger soon. I will unravel the mystery.

 

[Marty1781]

I kind of hate how the battery on this phone takes forever to fully charge, longer than any other phone I have owned, thought this was only on my first epic, but second is doing the same...why is this? any way to fix it?

In my case, I noticed that the time it took to charge the Epic was associated with the bad battery life I was getting. Doing a hard reset improved my battery life and at the same time, dramatically decreased the time it took for the battery to fully charge. So in my experience, it seems that the long charge time was due to the fact that for whatever reason, the Epic was simultaneously draining the battery at an abnormally high rate resulting in it taking a longer time to full recharge the battery. Once I fixed the battery life issues with a hard reset, the recharging time decreased significantly (presumably because the battery was no longer being simultaneously drained at such a high rate like it was before the hard reset). I no longer have the Epic but from what I remember, with the bad battery life, it took 4+ hours to recharge the phone and then once I did the hard reset, I could fully recharge a completely dead battery in under 2 hours.

 

[IBNobody]

The Pre charger charges the phone at 1A!!!!!!!

No... Just kidding! It's just charging at 590mA.

As you can see from the picture, I have the Pre wall charger (round, squat cylendar) connected to my current-sense passthrough cable. (The cable has D+, D-, and GND connected normally, but VCC is split to allow my DMM to be hooked up in current mode.) That cable then connects to the Pre's official USBmicro cable.

It's odd that it is only pulling 590mA and not 600mA. I think I must be having cable loss with the Pre's cable.

Anyway, the Pre charger is not a magic bullet.

Any other chargers you'd like me to test?

 

[Skunkape60]

In my case, I noticed that the time it took to charge the Epic was associated with the bad battery life I was getting. Doing a hard reset improved my battery life and at the same time, dramatically decreased the time it took for the battery to fully charge. So in my experience, it seems that the long charge time was due to the fact that for whatever reason, the Epic was simultaneously draining the battery at an abnormally high rate resulting in it taking a longer time to full recharge the battery. Once I fixed the battery life issues with a hard reset, the recharging time decreased significantly (presumably because the battery was no longer being simultaneously drained at such a high rate like it was before the hard reset). I no longer have the Epic but from what I remember, with the bad battery life, it took 4+ hours to recharge the phone and then once I did the hard reset, I could fully recharge a completely dead battery in under 2 hours.

How do you "hard reset" the Epic?

 

[Njphenom]

It still takes awhile but it seems like my epic charges faster in my car than at home

 

[ragnarokx]

How do you "hard reset" the Epic?

On the home screen, tap on Menu > Settings > Privacy > Factory data reset

 

[Marshmallow713]

I'm actually using my Zune charger and it seems to charge faster than the standard charger, but that may just be in my head. Its for sure faster than plugging it into my laptop to charge.

 

[HAAS599]

I also use a Zune 1A wall charger and a power only USB cable. I can get about 50% charge in a hour with the phone not in use.

I've noticed that if you get the pop-up with three choices when plugging in the phone, it will charge slower than if you plug it and it goes straight to charging. Whether or not you get the pop-up depends on the power source and cord you use.

 

[Marshmallow713]

I don't know about that last part, but I do always seem to get the pop-up with my generic USB chord and my Zune charger, which is odd considering this same chord doesn't give me the pop-up when I plug it into my PC. haha