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I have a laptop with a fried charging circuit.
I plan to disassemble the battery and connect the leads to a 12V PC PSU.
The problem is, is the 12V within the battery cutoff range?
The battery is 14.4V Lithium Ion tech, 4400mAh capacity.
Would a 12V supply work?
Gala
Posted 2016-01-05T16:27:54.527
Reputation: 177
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I have an IBM Thinkpad 600 that works well with a 12V car battery connected through the battery bay, but its battery was 10.8V not 14.4V.
Cutoff voltage for a 14.4V Li-ion battery is usually 12.0-12.8V (3.0-3.2V/cell), so it might work if you can get the PC power supply to produce more than 12V. Most PC power supplies struggle to produce 12V unless the 5V and 3.3V outputs are well loaded. If they are then the 12V output might actually go above 12V.
If your PC supply can't put out enough voltage then you could try connecting the laptop to an auxiliary 12V output in your car, which should produce 13-14V with the engine running. If that works then you could use a standard 13.8V power supply designed for auto accessories.
Bruce Abbott
Posted 2016-01-05T16:27:54.527
Reputation: 131
I tried 12V, wont budge. The battery board has individual sell voltage measurements and diaglnstic LED's.
I am thinking of making a DC/DC to up 12V to 14.4V and add voltage dividers for the cell sense.
Would this be smart to do? – Gala – 2016-01-06T16:02:42.870
If the board is monitoring individual cell voltages then it may refuse to start if any cell's voltage is too low. Try the voltage divider first (hopefully the diagnostic LEDs will tell you if it is working). If that isn't enough then try a higher voltage source (eg. car battery, or the original laptop cells charged up) before making a boost converter. – Bruce Abbott – 2016-01-06T17:27:12.013
6DON'T! DO! THAT! charging is not about connecting to a voltage. Unless you are preserving the charging circuitry.. – Eugene Sh. – 2016-01-05T16:33:52.367
1Are you trying to charge the battery or are you trying to replace the battery with the power supply? – None – 2016-01-05T16:39:46.970
1By "charging circuit" do you mean the AC adapter brick? You can usually replace these with similar rated ones - read the label - usually 19V, 3 or 4 amps. – Brian Drummond – 2016-01-05T17:11:54.330
1I am trying to replace the battery with a PSU. So cable is plugged in where the battery was. No battery charging is involved. I am trying to power the laptop.
For more info, the battery is 8 Samsung 18650 cells. – None – 2016-01-05T17:17:56.010
1The battery usually has a controller that will identify the battery pack to the computer. Even if you connect power, the computer will not turn on because it does not think that a battery is connected. Why can't you just connect the power supply cable that came with the computer? Also, what type of computer is it? – 3871968 – 2016-01-05T18:42:29.427
Some PCs will not power up without a battery in place (either by design or other issue), some factory recovery media will not work without one either, and most will not do a bios update. – Moab – 2016-01-05T19:17:36.163
Sounds like the internal charging circuit in the laptop is fried, so this is the only way to power the laptop, Am I correct? – Moab – 2016-01-05T19:20:13.927
Yes Moab that is correct. – Gala – 2016-01-06T16:01:42.670