# Battery powered water bottle boiler? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [May 15, 2017, 2:17pm UTC](https://boards.straightdope.com/t/battery-powered-water-bottle-boiler/786646 "2017-05-15T14:17:16Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![dude\_robert](https://avatars.discourse-cdn.com/v4/letter/d/8e7dd6/32.png) [@dude\_robert](https://boards.straightdope.com/u/dude_robert)\ **Post date:** [May 15, 2017, 2:17pm UTC](https://boards.straightdope.com/t/battery-powered-water-bottle-boiler/786646/1 "2017-05-15T14:17:16Z")
What are some ideas for a mobile water boiler, like a kettle but much smaller and runs on batteries? It would be very useful to be able to take some cold water from a tap and turn it into boiling water some minutes later. Would a 100-200w element be enough to boil a litre or two of water? I could keep the battery pack in a PVC pipe and just have some crocodile wires hanging off one of the ends of the pipe. It would look basically like a PVC pipe but with both ends sealed and some wires hanging off it. Could probably even make 2-3 of these and attach them together and stick them in a backpack, or just put them on the back of the backpack, all 3 PVC pipes joined together. So do you think this would be feasible? Or just a waste of time and money? I’ve been fantasizing doing something like this for months now… ---
**Author:** ![QuickSilver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quicksilver/32/7832_2.png) [@QuickSilver](https://boards.straightdope.com/u/QuickSilver)\ **Post date:** [May 15, 2017, 2:37pm UTC](https://boards.straightdope.com/t/battery-powered-water-bottle-boiler/786646/2 "2017-05-15T14:37:35Z")
Bored? Maybe read something. Exercise your mind. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 15, 2017, 2:51pm UTC](https://boards.straightdope.com/t/battery-powered-water-bottle-boiler/786646/3 "2017-05-15T14:51:46Z")
Maybe you could rig it all up to a pressure cooker. Also, make sure you mutter “Allahu Akbar” a lot while you carry it. Should be fine. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [May 15, 2017, 3:19pm UTC](https://boards.straightdope.com/t/battery-powered-water-bottle-boiler/786646/4 "2017-05-15T15:19:33Z")
> [@dude\_robert](#): > > What are some ideas for a mobile water boiler, like a kettle but much smaller and runs on batteries? It would be very useful to be able to take some cold water from a tap and turn it into boiling water some minutes later. > > Would a 100-200w element be enough to boil a litre or two of water? I could keep the battery pack in a PVC pipe and just have some crocodile wires hanging off one of the ends of the pipe. It would look basically like a PVC pipe but with both ends sealed and some wires hanging off it. Could probably even make 2-3 of these and attach them together and stick them in a backpack, or just put them on the back of the backpack, all 3 PVC pipes joined together. > > So do you think this would be feasible? Or just a waste of time and money? I’ve been fantasizing doing something like this for months now… > [@QuickSilver](#): > > Bored? Maybe read something. Exercise your mind. Actually, I recommend doing the math to exercise your mind, OP. My off-the-cuff calculations (using Google to find tools to do the calculations) tells me your batter pack would need two pounds of lithium-ion batteries to power a 200w immersion heater for 1/2 hour to boil up 2l of water from room temperature. One time, after which your battery pack is (A) flat and (B) probably damaged from being completely discharged. But Li-ion is just about your only choice, since almost everything else has much worse energy density (so you’ll have to carry a 7-pound battery pack of Ni-Cd rechargeables.) Maybe NiMH, which looks like a 3-pound battery pack and maybe less dangerous in case of rough handling. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 15, 2017, 3:36pm UTC](https://boards.straightdope.com/t/battery-powered-water-bottle-boiler/786646/5 "2017-05-15T15:36:29Z")
You have a tap for the water but no electric outlet handy? Batteries don’t make sense. A small propane or liquid fuel based heater would work. Campers do it all the time. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 15, 2017, 3:54pm UTC](https://boards.straightdope.com/t/battery-powered-water-bottle-boiler/786646/6 "2017-05-15T15:54:11Z")
[Here’s](https://www.amazon.com/RoadPro-RPBH-012-12V-Beverage-Heater/dp/B001AQZI64) one that works with a car battery. Might not be able to crank your car afterwards, though. ---
**Author:** ![xnylder](https://avatars.discourse-cdn.com/v4/letter/x/bbce88/32.png) [@xnylder](https://boards.straightdope.com/u/xnylder)\ **Post date:** [May 15, 2017, 8:40pm UTC](https://boards.straightdope.com/t/battery-powered-water-bottle-boiler/786646/7 "2017-05-15T20:40:23Z")
Is this for a camping trip, or for a steampunk project? If it’s for camping, I second **TriPolar** ’s point: Fuel combustion is much more efficient than batteries in that context. Even a small charcoal or wood fire can boil water if you’ve got a container and time. (For example, see this [camping samovar](https://en.aventurenordique.com/universal-samovar-wood-stove.html).)Or, make tea or whatever you want in advance and store it in a thermos. Over the short term, it’s easier to keep a liquid warm than heat it up from cold. If it’s a steampunk project, go nuts. Just be careful and don’t burn yourself 🙂