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Nexus 7 Running without Battery

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By ho9984, Junior Member on 5th June 2013, 11:04 PM
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29th May 2018, 11:38 AM |#41  
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I've got mine booting with a 5V, 2.1A car charger. Battery says its full the way I've wired it in "first time soldering BTW lol" only problem I've encountered is trying to change USB configurations from charging to MTP, it just freezes and restarts its self
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29th May 2018, 11:44 AM |#42  
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Quote:
Originally Posted by molnardk

Hello everyone
I tried this mod (remove battery, red to red black to black wire without the small PCB)
When I plug in the charger, and I try to turn on the tablet, there is a little screen slash(about 0.2 second) and after that nothing, no boot or anything.
Can someone help me with this?

I did this and have a saying I've got a full battery and boots up
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1st August 2019, 02:28 PM |#43  
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Here's my modification. Thanks to aussie0Z for the idea to use the PCB board from a dead battery. Essentially I faked the battery's power by tapping into the 5 volts from the board. This does not require any new connectors nor the case modification. It does require a bit of precise soldering though.
The tablet thinks that it has a fully charged battery when powered over USB. Unfortunately my PC does not see the tablet when connected, even though the USB power is enough for the tablet to work. Maybe I fried my USB circuit while experimenting, I'm not sure.
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12th March 2020, 12:58 PM |#44  
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Quote:
Originally Posted by Snake Scaly

Here's my modification. Thanks to aussie0Z for the idea to use the PCB board from a dead battery. Essentially I faked the battery's power by tapping into the 5 volts from the board. This does not require any new connectors nor the case modification. It does require a bit of precise soldering though.

Thanks for sharing the pics. This looks like a clean, nice solution. I have a spare "parts only" N7 coming in the mail and I'm deciding which "no battery" mod to try first. I'll need to connect an OTG device (a Carplay adapter dongle), along with the USB power source to the micro USB charge port. Should be no issues with this setup with the proper OTG adapter cable/splitter?

Quote:
Originally Posted by Snake Scaly

The tablet thinks that it has a fully charged battery when powered over USB. Unfortunately my PC does not see the tablet when connected, even though the USB power is enough for the tablet to work. Maybe I fried my USB circuit while experimenting, I'm not sure.

Curious if anyone else has tried this mod and can confirm.
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20th March 2020, 05:23 AM |#45  
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Quote:
Originally Posted by gregersrygg

Yes, it's possible to power the Nexus 7 without battery from a USB-cable, but it involves sending power directly to the battery connection inside the Nexus 7, and it seems to have some side-effects.

The battery is a one-cell lithium polymer, which has a max charge of 4.23 V. I hoped the Nexus wouldn't fry when connecting 5 V, and it has worked fine the few minutes I've tested it. No smell of burnt electronics

Here is what I did:
Tear off the tape around the battery cable. You'll see it's soldered to a pcb-board, and the two black and two red wires are soldered together. The two wires in the middle is probably some kind of data-connection to the battery. Will investigate this further later.
Then I soldered loose the cables, so I could use the battery-connector, and soldered both red and black wires to red and black wires in a USB-cable. Drilled a hole in the back-cover right below the NFC-antenna. The back-cover is filled with all sorts of antennas, so scratch carefully with a knife before drilling. Attached some pictures of the process.

Side-effects I've noticed so far:
- It thinks the battery is at 0% and not charging.
- The clock is reset when you turn off the power. But if you have internet it will update from NTP within a minute or so.
- My computer (OS X) can't detect it anymore. So I suspect it doesn't work in USB device-mode anymore, but I'm able to connect a USB-keyboard with an OTG-cable, so it seems to work in host-mode.

Does anyone else have any experience with this, or any ideas why it doesn't work in device-mode? I'm considering adding a small connector so I can use the two extra wires from the battery to the data-wires of the USB-cable (and disconnect when not in use), and then solder a USB female cable to the original battery. That way I can (hopefully) connect the Nexus 7 to my computer when needed, and possibly analyze what the two extra wires is actually used for.

I have CM for Android 4.2, and Timur's USB-rom, but it's probably not needed for this hack, and I will probably install a stock rom if I get this working properly.

Be careful, and don't blame me if you fry your Nexus (or anything else). Be sure to turn off any fast-charge hacks when the battery is disconnected.


Threads are sorted by last post in each thread, so it's impossible to find which one you are referring to. Do you have an url?

you cant put a protection diode in series with the power lane and it will reduce the voltage 0.7V, maybe it helps you.

that will also prevents the battery circuit to give inverse current to the pcb (charging), maybe it fried ur usb controller, its a win/win putting a diode in series.
17th May 2020, 03:42 PM |#46  
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Do anyone have some solution what to do to get n7 working properly and still have working usb otg? I want to instal my n7 in car but i need to remove the battery- when it gets really hot i dont wanna fire in my car :C
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