I would like to try to make an external battery for my laptop. I opted for 18650 batteries. (but feel free to tell me if there are better batteries for that).
I read this answer to a question here: How to build an external lithium battery pack for a laptop with 19V DC input?
Now, I have a question: Can I take eight 18650 batteries with cut-off at 2.5V?
Minimum: 8 x 2.5 = 20V => good to use only a buck converter! But if regulation fails, my laptop dies.
I'm surprised cause Russel said:
6 or more cells with a linear regulator:
- Not preferred but may be bearable.
- 75% to 98% efficient across falling battery range.
- Regulator failure MAY destroy laptop.
But I though it was the least efficient of the regulators!
So, which is better? Buck or boost regulator? The output current will be 2 to 3A.
Can I add a Schottky diode to every battery to decrease current drawn from each cell? Does anyone have a reference for a 2-3A diode with the smaller forward (?) voltage?