Battery drain connecting to HDMI via MHL

TabGuy

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I've been experimenting with connecting to HDMI via an MHL adapter. The results are pretty good except for the battery drain.

I'm using a Samsung 2.0 amp charger that is plugged into the MHL adapter but it isn't enough as the battery drops about 10% in about 20 minutes. Is there any way to keep the battery from draining during the out of HDMI?
 

kris.richards

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Depends on what you're watching/viewing I'm sure. I've never used one personally though. If the OEM charger isn't sufficient than probably not to answer your question.
 

DroidXcon

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I've been experimenting with connecting to HDMI via an MHL adapter. The results are pretty good except for the battery drain.

I'm using a Samsung 2.0 amp charger that is plugged into the MHL adapter but it isn't enough as the battery drops about 10% in about 20 minutes. Is there any way to keep the battery from draining during the out of HDMI?

There is an app called Screen Standby in the playstore, this will shut off your screen while you are connected via MHL cable.By doing this your device will not waste power activating the screen.
 

TabGuy

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There is an app called Screen Standby in the playstore, this will shut off your screen while you are connected via MHL cable.By doing this your device will not waste power activating the screen.

Yes, I used that on my Galaxy Nexus. Unfortunately, it requires root which I haven't done on my Note 2.

I'm getting a Samsung docking station which, if I understand correctly, solves this problem and actually charges the phone while watching TV via HDMI. I'll report back later as to what the results are.
 

DaRkL3AD3R

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Yes, I used that on my Galaxy Nexus. Unfortunately, it requires root which I haven't done on my Note 2.

I'm getting a Samsung docking station which, if I understand correctly, solves this problem and actually charges the phone while watching TV via HDMI. I'll report back later as to what the results are.

Almost positive the MHL should charge it as well. The dock will be essentially a glorified MHL adapter with USB OTG ports. Really not sure what's going on with that. My MHL doesn't drain my phone at all really. It charges, albeit slowly.
 

TabGuy

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Ok, I got the docking station yesterday and used that with the supplied power adapter for a 90 minute test. This performs better than the MHL adapter but the battery still drains. After 90 minutes my battery went from 78% to 69%. That's about 6% per hour which is acceptable for my football tailgating purposes. I'll live with it.
 

JabawokJayUK

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I have the same issue with a UK spec Galaxy S4.

The issue is that any MHL device is seen by the phone as USB, so the charge rate is only at 500Ma rather than A/C charging which is 1-2Amps. The only way I can see to fix this is to enable the Fast Charge Kernel Mod in a custom kernel so that you can tell the phone to draw current at 1-2Amps from a normal USB charge, but I can't see any custom Kernels for the S4 that have this feature enabled.

Anyone else seen anything?
 

cj100570

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I've been experimenting with connecting to HDMI via an MHL adapter. The results are pretty good except for the battery drain.

I'm using a Samsung 2.0 amp charger that is plugged into the MHL adapter but it isn't enough as the battery drops about 10% in about 20 minutes. Is there any way to keep the battery from draining during the out of HDMI?

If you're using MHL out your phone will most likely not charge as it will use more energy than can be supplied by the adaptor. I can't find the article now but the power output of most MHL adaptors is than the typical charger.
 

MeetMHL

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Hi - this is Krista from the MHL team. This is a general issue as it really depends on how the phone is being used while being charged. For example, just playing back streaming video with a charger directly attached to the phone might still drain the battery as the phone is using more battery than it can charge. Hope that helps - Krista.
 

YouAreWrong

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That is the wrong information from the MHL team there Krista. You can run gps pandora and video playback at the same time and the phone will increase in charge as long as it is plugged into a 2 amp charger and is drawing a current 2000ma or higher while showing in that it is charging to A/C and not USB. When the phone gets plugged into the mhl it only allows 500ma and shows as USB so of course there is a drain because the current is not strong enough. As the OP stated there needs to be an option to fast charge in the kernel that lets the mhl adapter put out a high ma flow of 1000ma or more (really needs to be at least 1700ma). So saying this a problem without the mhl is not true as long as the phone says charging in A/C and a 2amp charger. Please don't be feeding these people the wrong information before you test the proper drainage of a battery and the current flow. As to help out with the kernel I don't see one currently that lets fast charge to up the rate with a mhl adapter plugged in.
 

Sam Urai

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Maybe I am posting to an old topic. But recently only i started using MHL connection to connect my old Samsung S3, to use it as a TV Box.
I bought a generic MHL cable with 3 connection points, microusb, HDML and a USB. The power adapter to the USB is indeed not enough to charge the phone while on MHL connection. Thus, the battery on S3 is draining very fast, making it useless as a TV Box where before one 90min movie finish, your battery will finish 1st. Below is the modification and tweak that I have done to the whole setup and now the above draining issue is fully resolved.
1 installl a custom kernel that enable fast charging by USB: i install Boeffla kernel and configure the USB charge rate to 1100mah or higher

2. i have add 1 more power source to the whole cable, by cutting open the original cable near the microusb connector. Cut the red and black small wire inside the cable. Add 1 USB to microusb cable which i have plenty due to frequent upgrading of smartphone. Do the same to this extra cable by cutting near the microusb connector,thus exposing 4 small wire, black, red, green and white. The green and white is for data which is of no use here. Now connect both the red and black wire from the extra cable to the MHL cable. Seal it up nicely.

Whoolah!!!!!!!! Now you have a fully functional MHL system that do not drain battery. Instead, it will charge your phone as well.
 

Ben Dobson

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My Xperia Tab Z was draining faster than charging using only the Sony MHL adptr, so I took apart the Sony dock to use the side contacts and parts from within the dock to use another USB cable to plug adptr and there is now no drain when streaming Live BT Sport and even trickle charges about 1% every half hour or so.
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