Dell laptop power supplies have a microchip in them and the computer won't work properly with any power supply.

I want to use my own battery to power the notebook through the 19.5 volt DC port.

I'm going to open up the AC to DC power brick and tap directly where the 19.5 volts is created after I assume a transformer is.

I will then have my batteries (batteries will be connected to a DC DC converter to get solid 19.5 volts) to input the 19.5 volts directly into the power supply where the 19.5 volts is created from the 120 volts AC. This should also make the microchip work properly.

Just wondering if you see any issues here?

 

Just wondering if you see any issues here?

Yes. The Dell power supply microchip communicates with the PC. Perhaps the 19.5V generation doesn't happen until the PC is happy that it has the 'correct' brand of supply?

 

I took the chip out of the psu and put it into the laptop, its a 3 pin chip To92 case, that way you can use any psu with the same plug.

Your laptop brick is a switchmode psu.

 

I took the chip out of the psu and put it into the laptop, its a 3 pin chip To92 case, that way you can use any psu with the same plug.

U know about this stuff ??

 

Oh yes @Riffa, its a DS2501 chip, it uses 1 wire comms on the centre pin.


http://www.laptop-junction.com/toast/content/inside-dell-ac-power-adapter-mystery-revealed

I got sick to death of my laptop not charging because of the lead was broken at the plug, so i took the chip out and soldered it inside the laptop at the power jack, and now i can use any psu with 19V,

 

Oh yes @Riffa, its a DS2501 chip, it uses 1 wire comms on the centre pin.


http://www.laptop-junction.com/toast/content/inside-dell-ac-power-adapter-mystery-revealed

I got sick to death of my laptop not charging because of the lead was broken at the plug, so i took the chip out and soldered it inside the laptop at the power jack, and now i can use any psu with 19V,

Thank you..much appreciated.

 

I will then have my batteries (batteries will be connected to a DC DC converter to get solid 19.5 volts) to input the 19.5 volts directly into the power supply where the 19.5 volts is created from the 120 volts

That input voltage is not that critical being everything inside your laptop runs off of their own DC - DC converters which by design are not the least bit fussy about their input voltage variations being most use the same converters when running off battery power which is way lower than the external input voltage is.

If you are within -3 to +5 volts the internal converters will handle it just fine.

The last place I worked at we had a number of dell laptops where when out in the field we ran them off generic 12 volt vehicle power converter units with adjustable outputs from 14 - 24 volts and they worked just fine on any setting between 16 and the full 24 volts.

 

That input voltage is not that critical being everything inside your laptop runs off of their own DC - DC converters which by design are not the least bit fussy about their input voltage variations being most use the same converters when running off battery power which is way lower than the external input voltage is.

If you are within -3 to +5 volts the internal converters will handle it just fine.

The last place I worked at we had a number of dell laptops where when out in the field we ran them off generic 12 volt vehicle power converter units with adjustable outputs from 14 - 24 volts and they worked just fine on any setting between 16 and the full 24 volts.

That is good to know because I want to use 6 18650 batters which will have a voltage range of about 24.6 volts to 19.8 volts. The power supply is rated at 19.5 volts.

 

Dell laptop properly.

Just wondering if you see any issues here?

As i said earlier, post#5,, you will need to put the DS2501 chip on the centre pin, if your laptop psu is not charging its because it cant see the chip in the psu, usually its the cable at the plug thats broken,

I would remove the chip and solder it inside the laptop or, replace the lead.

 

So far so good!
From my dell power brick connector, I temporary jumped or connected the V- and center pin to my own power supply without even opening up the power supply, and it works! It reads the 2501 chip and doesn't give me that power supply error on start up.

All it needs from the dell power brick is the V- and communication, it gets its v+ from the laptop.

I then crossed my fingers and turned up my power supply to 24 volts, and it works! This means I can use my own 6s lipo pack and charge it to 24 volts. Thanks for that tip, I would have had to use an extra converter.

Now the big question, and I'll be crossing my fingers again.

I want to cut my original power supply wire, and basically tap into the V+ and V-, so that I can use it with AC power or battery power. All I need to do is just connect my own battery into it. This would make the 2501 chip work and not give me the error. I then would not have to open up the power brick as this one I have is very sealed tight.

So the question is, will connecting my own power to the V- and V+ of the dell power brick wire backfeed into the dell power brick and break it, of course I will have the AC power unplugged.

I don't see why it would break it.

 

So it works, I can connect my own power into the dell power brick.

Now I can power my laptop through AC, or just plug in my own 18650 battery pack.

When I get everything finished, I'll post a picture of the modified power brick and my own 18650 batteries.

 

Here it is, the modified dell power supply to take my own batteries and it works.

Does anyone know what would happen if I plug the power brick into AC power, also connected with my batteries?

 

It should charge your nicads up, as long as the DS2501 chip is on.