https://cauldryn.com/

An electronically powered mug that will keep your coffee hot or boil water for actual cooking. When we bugged out last year one of these would have been very handy. Cook inside your vehicle without the complications of carbon monoxide.

Some models have USB so you can shuttle electrons around to lights and phones, etc.

No direct experience, but this looks intriguing....

They don't advertise the wattage of the heating element. At least I couldn't find that on their website. Without knowing that, you have no idea how long it would take to boil water. If it's not a powerful heating element, it could be like putting a pot of water in your oven set to 212 degrees. You would be waiting a LONG time for that to boil.

They have 12v immersion heaters:

https://www.amazon.com/Travel-Chocolate-...8SZA9R7VMG2FN4T

But I would use great care with one of these. First, your car's cigarette lighter plug may not power the thing (you possibly/probably could blow a car fuse). You might need to hook it directly to the car's battery, not via an outlet.

150 watts (as this immersion heater advertises) at 12v equals 12.5 amps. You might melt those thin-ish looking cables on the device at that amperage. And you might need an oven mitt to handle it. Is your cigarette lighter plug wired/fused for 12.5 amps? It's probably fused lower than that!

Notably, this immersion heater doesn't declare itself to be "UL Listed". I wonder why...

The original mug discussed in this thread advertises a separate 5v LiIon battery to power it. If the mug's heating element is, say, a measly 100 watts, lordy lordy, that would require 20 amps! You wouldn't even need a heating element to warm your coffee at that level. Drawing 20 amps out of one of these small LiIon batteries would heat it up so much that the battery alone would heat your water. No need for an external heating element. Just short the battery and drop it in your water directly.

Makita make a cordless coffee maker. Seems to make better sense if already have invested in batteries. Though says a 5Ah battery is just good for three 5 ounce coffees, each taking 7 mins.

Call me old fashioned, but I started using the pour-over method for making coffee when my last coffee maker died. I can boil the water any way I like and then pour it over the coffee grounds using the same carafe and #4 filter as I used with the coffee maker. I’ve use this every day; last time we had a power outage I brought out the butane burner to boil the water and had coffee quicker than on the 220VAC stovetop burner.

That’s for making coffee. As for keeping coffee hot all day... who does that? Geez, if the coffee is so old you need a powered carafe to keep it hot you are taking too long. Make a fresh cup, your taste buds will thank you. This looks like a solution in search of a problem.

Russ, we r with u. We use a Melita single cup top pour thru and #4 filter, every day. Often several times a day. Wouldn’t have it any other way.

We’ve been thinking of purchasing a butane single top cooker for blackouts & other electric interruptions. Did u research ur buy or was it spur of the moment. What model do u recommend?

Mine is similar to the Gas ONE GS-1000 Portable Butane Gas Stove except it came with a stainless steel body.

If I were to buy one today I’d look at the Iwatani 35FW Portable Butane Stove. It gets good reviews, but it’s a bit more $$$.

A couple words of warning. Watch the ventilation, it is a gas stove. Do not use a pan/pot that extends over the fuel canister, it can cause excess heat in the canister and that might be seriously bad.

OTOH, an MSR Pocket Rocket can boil water. That and a copper kettle (old Revere ware) are in my truck kit.

I could not find it either and they do not list a time to boil the water. I think that is kind of suspisious.


Actually they do not. The USB output has 5 V (which is USB spec). Nominal voltages of LiIon batteries are multiples of 3.7 V. The ratio between battery capacity and Watt hour rating for the battery that comes with the mug indicates a single cell LiIon battery (which would be a nominal 3.7V). Typically an optimum discharge current would be at about 3 A and a high current while maintaining medium battery life at about 10 A. 10 h battery life (presumeably for keeping it warm) do not indicate a great insulation.
I would not buy this mug.

- My teardrop camper has one very similar to the above with about 8,000 BTU. The problem with butane is that is only good to about the freezing point. Butane bottles in packs are relatively economical.
- My MSR Micro Rocket I believe is about 8,200 BTUs on IsoButane. IsoButane is NOT economical but definitely convenient.
- My old Coleman Xtreme running on propane/butane mix has about 14,000 (I still have a box of fuel canisters for that beauty! Its perfect for the winter months but when I run out, I am out forever.)

Russ: Thanx for the quick response. I’m thinking of purchasing this as an emergency back-up for power outages. I read the reviews on both stoves u mentioned. They both are highly rated. But the Iwatani is almost triple the price of the Gas ONE. I respect ur opinion. Please tell me why u favor the Iwatani over the Gas ONE.

Purely subjective I suppose and that’s if I was buying one today. The Gas ONE is a great stove and meets all my needs in that class. The Iwatani seems to be built more to commercial standards and if I were in the market today, a year from now I wouldn’t miss the extra $$$.

Russ... the Gas ONE GS3400P that uses the 1# propane bottle in addition to the butane canister looks like a good candidate to replace my single burner bottle stove... I used it to pour through my low tech Mr Coffee for single cup coffee and tea for the 3 day outage during Irma...looks a lot more stable than the bottle burner...

anyone have comments about the propane version... I routinely refill 1# bottles during hurricane season

The Iwatani is a great little burner!

USB generally tops out at 4.5W, with most USB ports being less than half of that. A 12V power outlet in a car is generally 60W or more.

A 60W heater can provide just over 200 BTUs of heat: much, much less than any reasonable camping stove.

I might use a USB-powered thing to maintain a warm beverage, but I don’t think it would work very well heating cold water, and I sure as heck wouldn’t want to try it for boiling even a small amount of water.

If my reading is correct, there’s another adaptor that can be used which allows the stove to be fueled with a 20# propane tank. 20# of propane would keep you heating water and cooking for an extended outage.