Often schematics will show a ground connection to the battery negative terminal.
When designing PCBs nets and connecting components to the battery negative terminal, the software (I’ve used Eagle, FreePCB, and Pad2Pad) will often attach the terminal to the ground plane instead.
Is this ok? At the end of the day, all of my component terminals that connect to battery negative end up connecting to the ground plane rather than directly to the battery negative.
On one hand I like this behaviour because a components can be quite far from the battery and still connect to the ground plane with a via without running a long trace. On the other hand, I wonder if there is some kind of drawback to having one large plane with negative attachments all over the place with only one positive outlet connection somewhere on the plane.
The software I use lets me put isolated ground tracks inside ground copper pour areas or groundplanes when I need direct connections. It’s very useful.
This does increase capacitive load but it’s pretty small. There are cases where you will need something other than a general ground plane, though.
Some devices use a “star ground”. The datasheet will have this information. For example, the Allegro 3977 stepper controller calls this out. In this case I think it’s due to low value sense resistors connected to ground.
There are other cases where you isolate two grounds. I’ve seen it for a switching PS on a larger board. They used a small connection (50 mils or so) between the two larger copper pours. There’s an article floating around that explains this and when you want to do it.
In general, it’s not that important. Look in the datasheets for something like “PCB Layout guidelines” if you aren’t sure.
You can create a “battery 0V connection”, GNDb for example. And a virtual component which connect GND to GNDb. You will be able to place the connection point where you want.