I would be most grateful if someone with more experience of using KiCAD 6.0 than myself could advise me how best to have 2 x batteries on a schematic with 1 x battery holder ( with 4 pins ) on a PCB.
I looked at the current parts in the libraries, but none seems to show how to do this.
I also looked at ‘Alternate Pins’ though this dosen’t seem to solve my problem.
Any advice would be greatly appreciated.
Many Thanks !
In KiCad there is just a weak link between schematic symbols and PCB footprints, and for the “generic” schematic symbols.
KiCad just has two schematic symbols for a “battery”. It’s either single or multi-cell. you have to add the PCB footprint yourself anyway.
Batteries themselves come in many sizes, and for each battery size there are probably lots of variants of battery holders. Both from different manufacturers, and for holding a different amount of cells.
You can get “KiCad compatible” PCB footprints from sites such as snapeda and PCB Libraries, but those are generated from some database, and may or may not have some compatibility issues. In any EDA package it’s quite common to make custom footprints yourself, and KiCad has quite good editors for making new schematic symbols and footprints (or modifying existing ones).
I consider creating new parts an essential skill for an EDA program, and the quality of KiCad’s editors for these was one of the reasons to choose KiCad when I needed a new EDA suite.
Why does your battery holder have 4 pins? Battery holders for multiple cells usually have internal conductors. Some battery holders have extra mechanical metal pins just to solder the battery holder itself to the PCB.
Several options for Schematic and PCB:
• draw your own from simple to detailed
• download files from suppliers (mouser, digikey…etc)
screenshot shows simple Symbol for Battery and detailed TFT symbol, and simple 9v battery. I’m sure you can doodle-up similar for your needs
Hi paulvhd,
many thanks for the comments: All very valid !
Yes, the issue I have is essentially I need to assign 2 batteries to 1 battery holder: Assuming I use the ‘off the shelf’ battery symbol, it assigns pins 1 and 2 ( and if I use the symbol again for the second battery, it also assigns pins 1 and 2 ).
On the battery holder symbol ( which I drew myself using the symbol editor ), there are 4 pins: 2 x for battery 1 ( labelled 1 and 2 ) and 2 x for battery 2 ( labelled 3 and 4 ).
I am trying to find the ‘correct’ ( most elegant ) way to use KiCAD 6.0 to go from the 2 x symbols to the 1 x footprint.
As to why the battery holder manufacturer decided to pin out each battery seperatly, I have no idea, but that’s my challenge.
As far as I can see, I can either make a second battery symbol changing pinjs 1 and 2 to pins 3 and 4: This seems clumsy. Or I can ‘hide’ two batteries BT1 and BT2 for example, in the Battery Holder symbol: Again this seems clunky.
Again, thanks for the quick reply.
I think a schematic drawing can have two options. 1. Draw everything, even those parts which do no go to a PCB board. It help understanding the workings of the device.
2. Design a PCB. Only parts which go to PCB are in the schematic. If a battery is not on a board, it is not shown, only connectors or holder is on the schematic diagram.
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If something need not a footprint (like your batteries) and I want to have them at schematic I make for them footprint containing only a drawing at CrtYd. I have done such for BMIS210F+BMIS210C. Both got symbol being rectangles (one little bigger than other) and placed at schematic one on the other (you can place battery symbols inside battery holder symbol). Then one had a regular footprint and the other only CrtYd rectangle.
In KiCad 6.x there are now options for having symbols that show up in only the BOM or only Layout or neither. So a battery symbol can not have any footprint and the sync to the layout is still 100%. This example is a hold-over from V5, where i made the footrpint for the battery just some silk-screen.
For your case, I would take the default symbols and save them to your own library and modify them as needed for the parts you want to use.
Make your own battery symbol with no pins and check the “Exclude from board” option. Then make a symbol with 4 pins for your battery holder.
hope those options help.
I would just add two pins to the schematic symbol and draw a wire between them on the schematic. I don’t see any reason to make it more complicated.
Hi BlackCoffee,
many thanks for the reply and the suggestion.
Hi Piotr,
many thanks for the thought: I think this was one of the options I was considering, so it’s good to know that someone else uses this method.
Thanks again.
Hi StecklerCircuit,
many thanks for taking the time to give me a pointer to a solution. I had something like this in mind, but your point about the BOM was something I hadn’t considered, so many thanks for that useful tip.
Hi paulvdh,
thanks again - As I said, I was looking for the most elegant KiCAD solution and I think you and the others that kindly responded have all given me useful pointers.
Hi LM21,
many thanks for the suggestion: Good point about differentiating the batteries ( not on the board ) from the Battery Holder ( on the board ). I hadn’t thought of that, so this is really helpful.
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