How to charge your phone in a 24V BJ73 (1 Viewer)

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Joined
May 6, 2023
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Location
Montana
Hey all, this is my first post on here. I bought my 85 BJ73 earlier this year and have made a few minor improvements, the first being a dead stereo that was wired between batteries for 12v. I removed all the previous owners wiring for burnt out off-road lights, XM radio, a CARBINE security system (unsure how effective that could have been on a manual diesel with no electronics in the doors) and some really strange car charging circuitry. After cursing the number of unnecessary sheet metal screws that were holding this all together, I got to work on my own Hippocratic solution (first, do no self tappers). It is hard to find a stereo that doesn’t look like a prize from a claw machine arcade game with shiny chrome and blue LEDs, so I opted for a new JVC touchscreen since it had the least number of offensive lights and buttons. The stereo I chose is also pretty thin, which came in handy when I went to find a 24-12V converter, which are a little chunky. I wanted something easy to remove, so I made a frame of aluminum that matched the original stereo dimensions to hold the converter behind the stereo so that they both came out with just a couple screws, and could be somewhat self contained. I traded the 24V cigar lighter for a USB CarPlay and charging port, but left the original wiring in case I wanted to reinstall that at some point. The converter is using the original stereo power wire, which is already switched on by a relay in the ignition. No battery drains by converter, but because I don’t have a good way to power the memory wire with a constant 12V, the stereo says 4am every time I start the engine until it syncs with my phone about two minutes later. The previous owner did spend some money on a 24V JL amp and speakers, so I can’t curse him too much.
Anyone else have a cruiser with CarPlay? 😂

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Hmm... I'm not sure that they have a constant output, anyway, so probably no loss. To be clear: the goal is solving the memory-wire problem, yes?

Edit: You're pulling 24v to the converter via the original power wire to the stereo, which is keyed. Could you not just add a constant 24v non-keyed circuit to power the converter, and keep it on? It should draw basically nothing, in and of itself... 🤔
 
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Hmm... I'm not sure that they have a constant output, anyway, so probably no loss. To be clear: the goal is solving the memory-wire problem, yes?
If I could solve the memory wire issue with a simple circuit, yes. Just don’t want to add anything between batteries like the last guy. It does remember my phone, so it works pretty well as is but it would be nice to not have to click “no” on the demo display on startup. Thought I’d see if anyone else had a solution other than using a 24v marine stereo since I liked how this one fits.
 
Yeah, don't go between the batteries. I fixed the same type of garbage on mine; that's definitely not an answer.
 
It should draw basically nothing, in and of itself... 🤔
I looked at configuration this initially and didn’t like the constant draw of the converter, albeit in the mA range. It’s an option, but Montana winters are pretty taxing on batteries already and any drain I can avoid I will. It would also require a 12v relay switched by the 24v keyed power between the converter and stereo since the converter would be always on, but that’s simple enough. Might give it a try.
 
how about one of the many inline bucks available as a standalone converter for the memory wire?
I saw those, wasn’t sure of quality or current draw. The price is right!
I even considered throwing a Milwaukee 12v battery in my glovebox as an option that would probably last a couple weeks without charging, but when the 3d printed battery adapter came it immediately got used in a different project. Funny how that works.
 
I looked at configuration this initially and didn’t like the constant draw of the converter, albeit in the mA range.

Well, if it makes you feel any better, I just started my rig for the first time in three and a half weeks, and my converter has been on the entire time. Batteries were sitting at 25.2V before cranking, and after about ten minutes they were charging at 27.8 or so.

It’s an option, but Montana winters are pretty taxing on batteries already and any drain I can avoid I will.

I hear that. Cold sucks. Literally.

It would also require a 12v relay switched by the 24v keyed power between the converter and stereo since the converter would be always on, but that’s simple enough. Might give it a try.

That wouldn't be difficult at all, and it shouldn't take up a lot of space...or you could just turn the head unit off via the power button, and skip the relay entirely. From the picture it looks like you have a power function on the Home button, but the relay would give you an additional automated option.
 

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