Elecrow PCB’s
Recently Elecrow provided the offer of $10 USD towards pcbs (Which can get one 5x5cm PCB shipped for free). The catch for this was to provide a review of the PCB and their service. I ordered two PCBs from this voucher, a yellow PCB that acts as an XT30 joiner board for setting up paralell connections between 3S batteries, and, a black PCB that is the top pcb on the openBMS project I’m slowly moving along on HackADay.io.
Black BMS GUI board
The Black UI board
This board is a fairly simple layout with minimal components. However I did order it in black soldermask, which is hard to get right but can look good when its done properly. The black solder mask is very shiny, and shows fingerprints and marks very easily. The soldermask did not bond overly well to where the copper was and does scratch off if you are not careful with the soldering iron when soldering. The effect of the black is very nice however, and does make a product look that little but nicer and more professional. However because of it scratching off easily I would not use it in locations where things may rub on it (such as faceplates). It does however bond really well to the substrate so if you have no copper on the front then it would be visible.
Yellow XT30 joiner pcb
Yellow XT30 pcb
The yellow PCB turned out really nice, the silkscreen is much nicer than dirtypcbs, and all the dimensions match my design as best as I can measure. There is a slight ripple in the outer milled edge in the lower left, but its perfectly acceptable and everything else is finished nicely. This was a simple pcb so I will not be using it to judge their equality at tiny sizes, but it worked out really well for my application.
All together now
Full unit stack
The full unit assembled, with the BMS board in the middle, a battery XT30 joiner on the bottom and the UI board on the top looks nice. All the dimensions line up and the whole unit fits together really nicely.
The unit does also work! The main thing left on this project is lots of code for the user interface so you can change settings and use the unit in everyday use.