Those most experienced Electrical Engineers in the world still occasionally release the magic smoke. Honestly, if you never do it, you weren’t trying very hard.
So… Good Job! 
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I once released it in my face for that matter… I had two electrolytic capacitors of the same size on my desk but different ratings and as you might guess, I used the wrong one while assembling a prototype. As I powered the thing up, it started buzzing so I leaned over the board wondering what was going on… And that little power supply capacitor blew up on my face leaving me utterly confused. Until I powered everything off and looked at the board.
I was trying so so hard not to too haha. Even went to the local maker space to use the dc power supply before hand. Whenever I do make magic smoke I always think back to mythbusters and how often Adam and Grant blew up electronics. makes me feel a little better knowing they did it too haha. Well I’ll have more time tomorrow afternoon to work on it. @enginerd if i operate without the jumper, will I still need to replace the diode? Or if I use the gnd side of the jumper. I don’t think I need 12v high for my purposes
I’m assuming that you fried the diode that’s on the xACv2. If you did, the board will not power on until you replace it or bodge another one between the pins that I mentioned.
I’m hoping that I diagnosed things correctly but would still like to know if your xAC powers up?
@enginerd is politely showing the diagram from when I burned out my XAC on my second safe project
There’s no big shame in it… I was able to fix mine, and even if you can’t they are pretty cheap and relays are weird… add in jumpers and stuff and it’s a miracle I didn’t break my first one
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The XAC operates as intended on the NC side of things, still registers my implant, and will open the circuit when scanned. Technically, in this state, I can “unlock” the door with the XAC by opening the NC circuit by scanning my implant, then as soon as my implant is removed(in 1 sec delay) it will trigger an unlock, but that means the internal door lock buttons don’t work because it thinks the unlock button is being held down. It also for some reason doesn’t work with the doors locked, the XAC still beeps but it doesn’t unlock the doors like it does when the doors are unlocked.
Hard to explain. But the main point is the XAC still works, just as far as I can tell only on the NC side. The NO side seems to be permanently NC now. It’s in my car right now working in jank “unlock” mode. Kinda also wanted to see if it would kill my battery overnight before I take it all apart again for more testing. I should have more information for you tomorrow night
You could do some calcs
The xAC V2= 60mA Idle
Do you have some sort of battery protection like a Low Voltage Cut Out?
You should be fine overnight, but if that is something long term you are considering, or put a Momentary on inline with your 12V power, so It only draws when powered
100mA Operating if you were wondering
No but my car likes to kill batteries even without additional parasitic devices. Just too many electronics. Alternator is fine, replaced before I bought it with an upgraded one for a sound system they had, and terribly removed before selling it. I’ll get all that worked out after I get it working as intended. I drive my car for work so there shouldn’t be any issues for the foreseeable future. I always have a charged jump pack, and worst come to worst I have push started it a few times since it’s a manual.
Fair enough, just have a membership there might as well use it. It’s 24 hour and uses RFID so it’s an excuse to use my implant and get off my butt and go make something 
It’s pretty cool what they’ve got there. Cnc machines, laser, mills, lathes,full woodshop,an array of 3d printers,etc. I just need to start taking their courses and start learning
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Maker spaces are probably the only thing I miss from living near a large city.
Regarding battery life, I’ve got a v1 xAC hooked up to a repurposed drill battery pack. It lasts about 3 weeks between charges. I could probably run it 4, but why push my luck? I don’t think it’ll even make a dent in your car battery as long as you drive it once a month or so.
@mfries18 go check out my second gunsafe project
It’s a long read… and not the most straight forward at first but it was a good project and I am happy with it
I too Am paranoid about battery being run down
I use an XACv2 in it, and additionally I managed to get a timer relay circuit to work, pretty much exactly like I’d rig it IF\WHEN I go for car, so that the xac is only powered when I need it to be, and not drawing power the rest of the time
You’d just need to figure out where you can add a button or switch to trigger the timer circuit
I want to rig a button to the bottom side of my side mirror
Thanks for the great info. I’d rather not wire a button up, just takes a hand away. I wonder if I could do a reverse smoke battery setup. Where it runs off a secondary battery until the secondary battery dies then it runs off the car battery. I have a super small 12v battery(about the size of 2 dangerous things implant boxes stacked on top of each other)that I could run in deep cycle…or just run in deep cycle and just hope it keeps up with charging, with how much I drive, I imagine it will be okay with just deep cycle. There’s just no backup if the secondary battery dies since they(the batteries) should only be connected when acc power is running
What do you mean?
In my setup you tap the button,
You wouldn’t need to hold it down
and it powers the reader for however long you program it, I’d probably set it for a minute or something
So in this video, my safe is running purely on battery power, and there is zero draw till I tap the button,
Then it’s powered for 30 seconds
You could even do some kind of foot tap on the bottom of the car if you wanted to be all hands free, but in context you still need to scan your hand soooo
Fair enough. I’ll probably just do deep cycle for now, I only have to run a couple extra wires for that. All interior wiring, no drilling of holes, just simpler. If a drill battery will last weeks then this battery should last a while longer. Can always make changes later(my door panel is pretty easy to remove)
You could use a Voltage Sensitive Relay (VSR), your alternator will charge your main start battery, then kickover to charge your “house” battery when it reaches a specific voltage.
something like this
or this
Wired like this
or this
I misdiagnosed the problem… You removed the S3 jumper, right? It looks like you’ve got a burnt contact in the relay of the xACv2.
You can replace the relay if you’ve got the soldering skills or can enlist help at a makerspace but I’d just order a new board.
I’ll see if we have a relay on hand. My dc circuit knowledge may be rusty but I can still solder damn well lol.
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On a previous similar project, the community came up with some power saving concepts for me.
- A switch.
- PIR Sensor to activate power.
- Touch Capacitive sensor to activate power.
You could also use a reed switch that’s closed by a magnet. IF you also have a Titan or xG3 in the same hand, and you lined up the reader / magnetic switch to be activated at the same time when your hand is in position. (Might make for tricky hand placement).
Ultimately, my solution was a bigger battery. Can you mount a second full size car battery under the hood and wire it in with heavy cables to the first? Bonus! You’d get twice as much reserve for starting, etc.