Hey! I’m designing a DC powered coffee brewer for hiking and camping because the portable ones out there, while nice, aim for espresso and i prefer brewed coffee, especially out and about, and the bripe is annoying to clean.
To get to my point, my design would call for 60W of sustained power at 12VDC for a while. There are powerbanks that can deliver this over PD but i have some really nice 18650s unused laying around and powerbank with removable cells can serve as an emergency cell source for a light or vape.
Is there a reputable make of empty powerbank cases that are physically and electrically solid, with all protections, balancing if in series, sufficiently sized components and deliver this amount of power over PD?
I feel like brewing coffee outside should involve flame, not plugging into electricity. I use alcohol stove and a drip cone. But even cowboy coffee would be just part of a nice outdoor experience.
It does, usually, i’ve got the Bripe, an Ikea french press piston that fits into my stainless mug, a swedish style kaffepanna, Aeropress, sometimes i’ll even bring the V60; with those it’s either an MSR gas stove or a small alcohol stove but they all have downsides, specifically
ideally you don’t use any open flame during wildfire conditions
less than ideal in tent or vehicle
alcohol and gas don’t work too well in freezing (or even just cold) and very windy conditions
Yeah it sure is a point of quirkiness (and my reason to have gotten it in the first place). The project I’m thinking of here is basically it in a vape form xD
Plan is to use a dual wall titanium cup, not more than 100ml and a 3D printer PTC cartridge (often come in 60W-ish). Discounting for losses that’s 7-ish minutes to bring 100ml of water to a brewing temp suitable for dark roasted coffee which is fine by me. At this point I’m choosing to not go over the 60W mark (e.g. by using 2 cartridges) b/c 65W PD is fairly commonly available.
What temperature are you going to aim for and how are you going to know when/if you get there? How many batteries do you reckon this device is going to need to hold?
Edit.
I assume you’re going to go in through the cap or lid. That keeps it easy to clean.
I think you’re better off with a Lithium-Ion jump starter that has a 12v barrel port. It will still be dual use in that you can jump start your vehicle if the battery is dead at the end of your camping outing.
I’m aiming for 80-85°C with dark roasts, higher with lights but that’s home stuff, not out-and-about stuff , indeed going through a (probably custom SLS 3D printed) lid with the cartridge encased in a stainless thermowell. With the temperature i’ve yet to decide, a nice PID thermostat with a timing function would be amazing but a bimetallic dial-style thermometer might just do the trick with less electronics to possibly break down. A jumpstarting powerbank is a good tip, i’ll look into those but at the same time those have no overcurrent protection unlike PD making things a bit scarier… also probably way over cabin luggage lithium capacity limit unlike some 65W PD powerbanks…
How big are you willing to go? Would some of the smaller power stations work? I have been testing this one:
It has a 12.8 DC output rated for 8 amps. It will charge via DC or PD at 100 amps. My testing has shown ~140 Wh capacity. Plus it has a few USB outs and can be charged with solar panels. Specs say 2 kg, so what 4.5 pounds. It also has a decent light built in.
Of course it won’t allow you to use those 18650s you mention in the OP. But it would get you the other part that you want.
This project I’d like to be backpackable but a power station is something i’m independently considering to have on hand. We’ve recently had a major brownout, a very rare event, but it showed some weak spots that i’d like covered, such as 24h fridge/ freezer autonomy.
If i end up opting for a compact power unit, i’ve got my eyes on one that is a decently compact 20Ah 65W PD unit that could be used for a 65W soldering iron or my li’l 12" powerhouse of a laptop </s>.
I have one of these: Amazon.com
It would probably do it, but hardly back pack material at 50 lbs. I got the second battery that basically doubles the capacity. With 400-500 watts of solar panels you can keep the refrigerator going for a while. But enough OT.
Oh yes that one is on the shortlist for sure! (230VAC version, that is) The extensibility makes it next level and without add’l batteries it could easily travel on roadtrips too.
Dang, that’s weird. Bonus points for using a torch! Although not the kind we talk about here. 
, indeed going through a (probably custom SLS 3D printed) lid with the cartridge encased in a stainless thermowell. With the temperature i’ve yet to decide, a nice PID thermostat with a timing function would be amazing but a bimetallic dial-style thermometer might just do the trick with less electronics to possibly break down. A jumpstarting powerbank is a good tip, i’ll look into those but at the same time those have no overcurrent protection unlike PD making things a bit scarier… also probably way over cabin luggage lithium capacity limit unlike some 65W PD powerbanks…
but a power station is something i’m independently considering to have on hand. We’ve recently had a major brownout, a very rare event, but it showed some weak spots that i’d like covered, such as 24h fridge/ freezer autonomy.