5
1
As the title says, I want to bypass the adapter detection, because it disables the battery charging, and slows down the CPU (I have killed this with ThrottleStop). The charger is working fine under full load, just the 3rd identification wire is broken somewhere, so the laptop can't detect it, and won't charge battery. I have never seen a such useless "feature", and there are no options to disable it. Tried to edit embedded controller with RW-Everything, didn't help. The following happens when I plug in the adapter, and charges for some seconds, then disables:
Byte 0x07 changes to 20, then E0 when it disables
Byte 0x3B changes to 30, then 31
Changing byte 0x06 sometimes brings up the QuickSet application's unknown adapter warning, for example at 01, 03, 09.
So maybe DSDT editing helps, but I don't know, how to do it. Is there any way to force the laptop to charge the battery?
UDPSend
Posted 2018-05-21T13:36:03.623
Reputation: 59
1“Useless” feature? It’s important that the laptop knows what size power adapter is plugged in so it can charge and power the system optimally. Being that you can buy generic adapters for under $10 and genuine adapters for under $30, it seems there is little need to do what you are asking. – Appleoddity – 2018-05-21T13:49:02.057
4I had many laptops, none of them disabled functions, even with no-name adapters. But Dell does, it kills the battery because it's drained to 0%, still no option to charge. I have genuine PA-12 Family (928G4) adapter, so why i'm forced to buy a new when this is working? Because Dell implented this feature... So i want to use my laptop without useless limitations. – UDPSend – 2018-05-21T13:57:59.063
How certain are you that this is the charger and not a defective battery? – Mokubai – 2018-05-21T14:12:01.023
Borrowed one from neighbor for testing, it got detected, and charged the battery. – UDPSend – 2018-05-21T14:20:09.877
1It's even worse than described -- We've have a bunch of Dells and random power supplies scattered through our company over the years. The worst is when it randomly won't detect a known good supply, as described above. I've got an Alienware, requiring the 190 Watt, and I'd love to be able to put it into "Limp Mode" and charge it slowly with ANY Dell adapter! – DaaBoss – 2018-05-21T14:32:33.820
Has anyone looked at the schematic or opened up a Dell and tried to figure out which pins to short? I needed to use my laptop and didn't have a 19V adapter with the right plug so obviously I thought the middle pin was +... and I fried the detection chip... Laptop still works fine but I can no longer charge it only run it off a power supply.... although, sometimes it does charge. I'm guessing it depends on when in the bootup cycle I plug in the power supply. – Dagelf – 2018-08-27T09:34:04.613
2
@Dagelf
I have solved the problem with disassembling the adapter, removing the identification chip from it, and directly soldering it inside the laptop, between idetification wire and GND. This site helped me: https://www.laptop-junction.com/toast/content/inside-dell-ac-power-adapter-mystery-revealed
If you fried the detection circuit inside the laptop I doubt this will work.
@Appleoddity It's not a feature at all. Any device can detect if the present power supply is sufficient or not by only monitoring the voltage (which is 19V in our case). If the voltage drops more than %5 or any preset limit, the device may stop using the power supply. This is only a bad decision in order to make more profit from the spare parts. – ceremcem – 2020-01-18T00:36:41.120
I can tell you what a good design would be: Measure the open circuit voltage of the present power supply, try to consume the needed power if its voltage is inside the limits. If voltage is being dropped too much, lower the charge rate. You can charge your battery from any power supply, it will just take longer if you connect a low power adapter. You can charge your battery up to 100% with a 0.1W power supply while your laptop's original power supply is 90W (you have to turn your laptop off if power of the adapter is less than the laptop's live consumption, of course). Easy yet useful feature. – ceremcem – 2020-01-18T00:45:44.050
@ceremcem I’m not sure I fully agree with your statement. A typical laptop, switching power supply has over current protection built in. A switching power supply should provide at least the power output it is rated at without a significant voltage drop. After over current protection kicks in, it will shut off. The laptop knowing the capabilities and status of the adapter connected offers several advantages in charging. I’m personally familiar with the much more advanced Dell charging algorithms than those that are non-existent on many other brands that do not communicate with the charger. – Appleoddity – 2020-01-18T01:08:46.027
@Appleoddity Adding a current limit (besides the overload hiccup protection) is a cheap feature for a manufacturer. An SMPS which has this feature will limit the output power, thus the voltage starts dropping intentionally while power demand tries to exceed the supply limits. This would be a good (and close to natural) communication protocol feature. If the user connects a low power source that has very strict voltage regulation, the SMPS wouldn't drop the output voltage until it enters the hiccup protection mode, which won't harm either.
– ceremcem – 2020-01-18T02:31:13.323@Appleoddity Could you give any example on Dell's charging algorithm that depends on this identification feature? – ceremcem – 2020-01-18T02:59:28.407
When user connects a different power supply that is not capable of delivering the required power yet has very strict voltage regulation control, the user will eventually notice that his/her laptop starts and stop charging at 10 seconds intervals so he/she will conclude that the charger is inappropriate. So, naturally it won't last much so it won't impact the battery longevity. – ceremcem – 2020-01-18T06:50:10.077