Timeshift works best if you use BTRFS for your root partition because snapshots can be taken instantly. I have mine setup to automatically take a snapshot every day.
The MOSFETs are in series, but in opposite polarities. Two MOSFETs are needed to block current in both directions.
The DW01 uses the voltage drop across the MOSFETS to measure the current. The overcurrent threshold voltage is fixed at 150mV. Using a larger MOSFET that has a lower RDS(on) will increase the current limit.
The drains in the 8205 MOSFET are connected together internally. In a DW01 circuit, they are not connected to anything else.
One MOSFET stops the battery from charging and the other stops it from discharging.
For something that’s not switching at a high frequency, slow rise and fall times are fine as long as you are staying within the safe operating area of your MOSFET. A 10K gate resistor could certainly work, but it will depend on your MOSFET and load.
Power consumption is the main issue. If it’s an old, power hungry desktop and you live somewhere with expensive electricity, it can be quite costly to run. If you have an energy efficient desktop or have cheap power then it will be fine. Just make sure it has a good quality power supply if it’s going to run 24/7.
The hard drive should be connected by SATA or eSATA when making the image. Connecting over USB is just asking for more trouble when the drive is not working correctly.
I’ve gotten both of my thinkpads used, so none of that money went to Lenovo or Microsoft. The laptops that come with Linux are expensive and are rarely available used.
I still get over 12 hours of web browsing or video playback with the backlight around 30% on mine even though my internal battery is down to 60% capacity and my external is around 90%. Standby drains about 10% overnight. I am running Linux Mint on mine and I set up TLP. Undervolting can increase the runtime quite a bit, but I haven’t bothered with that yet.
MELF stands for Metal Electrode Leadless Face although anyone who has had the pleasure of working with them will tell you it stands for Most End up Lying on the Floor.
The T480 and T580 are some of the last ones they made with swapable batteries. Everything works out of the box in Linux except the fingerprint scanner which needs some additional configuration.
I have a T480 with an integrated GPU and the largest battery. It runs for a long time on a charge and there are lots of spare parts available.