I want to make a very simple external battery pack for a laptop, connecting to its 19V DC power jack. I plan to use a series of four lithium batteries that should provide between 11V and 16.8V of power.
The internal battery pack consists of 3 Li-Polymer cells, which I assume provides the laptop with approximately 8.1V to 12.6V of power.
When I connect the 4-cell external battery pack to the 19V DC input, what are the effects? Does it make sense to assume that the laptop is fine with voltages below 19V? Will it take whatever voltage it needs to run, which should be related to what the internal battery provides, i.e ~8.1+V, and direct only excess voltage to recharge the internal batteries? Are there any terrible inefficiencies going on? Does this even make sense at all?
Answer
The answer is simple: We don't know because the laptop is only documented to run at 19 volts. It may work fine with less, or it might not work at all. Although remote, it is possible that even if it "works" fine with less voltage, running it for an extended period could damage something due to parts of it's power supply getting too hot.
We just don't know what is inside of your laptop. We also don't know the internal workings of every laptop in the world. Just because it might work with one laptop, it doesn't automatically mean that it'll work with any laptop.
If you want to be safe, take the output of your battery pack and bump it up to 19v. Otherwise, all bets are off.
No comments:
Post a Comment