3D printed battery upgrade for TDI-SL

Hello all. I'm new to prospecting and first forum post. I've been lurking here for a while though.

My plan is to 3D print a battery cartridge for my tdi which will allow a cordless drill 18v Li-ion battery to clip on below the control box. Inside the battery compartment will be a cheapo buck down converter set at ~16v and an led voltmeter. This is to improve performance, run time and I think the balance will be better also. Mine is slightly heavy at the coil end with the MJD 8x12 which came with it. I'd also like to run a larger coil once I start to find some yellow. The heavier battery should improve this somewhat.



My question is will the buck down converter and volt meter create electrical noise being so close to the circuits of the detector? One more thing, how much can I safely discharge my Li-ion batteries? Would 80% (20.8v down to 16.6) from full charge be safe for long term use?

If successful I will post .stl files and bom here for others to use. I'm also working on a design for a hand pump (65mm PVC with dual check valves and hose to bucket)for those who like to get their hands wet The .stl and bom for that will also appear here if it works out.

Thanks for your time and comments.

Good luck with the projects. Show us the end product if you can with a few pics.
Jaros

careful with that, the inductor style power supplies can make detector unstable. i would test first before going to the effort.

Eski said:

careful with that, the inductor style power supplies can make detector unstable. i would test first before going to the effort.

Click to expand...

Thanks for the warning. Is it likely to damage the detector if I try it out?

No, it won't damage it, well very unlikey, the emi from the inductor will be creating a small magnetic field, but more of a worry is the frequency it will be running at which would be sending emi into the circuit of the detector.
Honestly it's probably not a great idea, why not just make up another battery pack from some cells?

I had all those parts sitting around so it would have been a cheap upgrade. It looks like bigger cells go on the wish list. I may still try an inside/outside cartridge with 18650's to get the voltage, capacity and extra weight that I wanted.

Thanks for pointing that out and saving me the trouble.

You could always test it before going to the trouble of 3d printing a case etc.
If you were going to, mount the buck at the very rear behind the battery and fit a choke to the output like these https://www.jaycar.com.au/u15-ferrite-voltage-spike-protectors-noise-suppressors-pk-2/p/LF1294

But still it's turning a simple idea of a battery pack into a complicated one that may compromise the machines effectiveness.

What voltage do you need?
Perhaps something here may be of use?? https://hobbyking.com/en_us/batteries-chargers/batteries.html

Was just about to ask that.... What voltage/what detector.?

there are li-ion cells with self shutdown - i would use 4 of these in a gpx... but
for a gp/sd i would use self shutdown Li-Fe... Due to voltage.