What would be the best way to heat an EV

My dad and I have differing oppenions on this subject. My dad thinks that we should store 13 gallons of water in the car. And set a timer (or other mechanisum) so that after the car is done charging the power will be redirected and used to heat the water. Which can then be used to heat the car during the trip. He wants to use water because of its ability to retain thermal energy.

I think however that It would be better to just use a heating element (of some kind). And even if we needed an extra battery to run it. we would still be adding less weight that if we where to add a tank full of water.

Here is how I see it
We can heat the water more effiecanly that we can heat air by method of induction heating which is aprox. 90% effeciant. To heat air we would need a resistance heater which is about 40% effeciant (about 50% of the energy is radiaded, but that would heat the casing and then heat the air indirectly). The water would constantly lose its thermal energy where as the 40% of the energy generated by the resistance heater would not be wasted. So which one is more effeciant?

Also the water would add more weight and thus require more energy to move the car.

So any ideas (not just relating to our debate)
If you can think of a better way to heat the car I’m all ears

Thanks for your time

I would not pack around 13 gallons of water. The two main ways I’ve seen are to 1. build a small recirculation loop with the existing heater core, and a small imersion heater in a reservor. 2. Or buy a small ceramic, (or other element) heater and duct it into the heating ducts. 3. Anything that produces heat , (hair dryer, 12Volt plug in heater fan, etc…). You can pack a lot more thermal energy in a car battery than in 13 gallons of water.

Your best bang for your buck would be a gas heater like old VW bugs had. Sure they caught on fire now and then and it would defeat the purpose of your EV but it would heat your car nicely. You could also use a small propane heater then just remove it and the tank when you don’t need it.

I’ve been debating the solution to this for a while and still can’t make a decision. I am in Charlotte NC where it doesn’t get extremely cold for long and gets pretty hot in the summer for months. The basis of my thinking comes from my knowledge of energy conservation in homes and solar thermal water heaters, photo voltaics, geo thermal, absorbtion chillers, and passive energy collection and use.
My delima is most of the time I will be comfortable with adjusting the windows; why spend money and add weight to the vehicle that is permanent.
then a cold spell will hit or the s-10 will be scorching and I start thinking of a solution.
For the cold times I have been thinking of seat warmers that lay on the seat under a cover. With a hat, gloves, and a warm backside I should be very comfortable. How much range would it lose? I don’t know, but I think heating the whole compartment with a ceramic heater would impact range more, especially if the compartment isn’t tightly sealed. I would also preheat the compartment with a plugged in electric heater at home. The sun does the job durring daylight hours.
THIS DOESN’t address windsheild defrosting/defogging requirements. I had thought of just using RainX products and keeping the windows squeeky clean. I also thought of using a 6 gallon electric water heater that I would put on the highest setting, heated with house current(110) then pipe(heavily insulated) through the existing heater coil and use recirculated air feature. The trip lenght on a battery charge will be less than 2 hours and the hot water in the tank should be able to expell some heat for that long. When the season changes, I can unhook the water heater.( est. weght: 75lbs. full)
AN IMPORTANT ELEMENT to any solution would be to first reduce air leaks of the cab as much as possible. I am also adding sound and radient insulation in the roof, floor and side panels a long with window tinting. I am using very light weight aircraft material, but several materials are available from auto supply stores.
As for the summer: Window tinting and insulation will be my first step. Solar window fans and parking in shade or under cover when possible. Old fashioned straw seat coushions that lets air circulate all around the body. And as a last resort a swamp cooler set-up. I have seen one unit advertised that blows air over ice water into the cab through hoses. The hoses where not insulated and there wasn’t an air return from the cab, so I didn’t think it would work that well. I had 2 thoughts about changing this system: #1 use the heater core and circulate the ice water from the ice chest. Block ice works best, but ice cubes are good. #2 rig the cooler with air return that circuates through the ice water (bong style) to dump BTU’s and have more time to cool cab bound air. This would be harder to do; air tight seal & stronger blower = more battery drain.
The current solutions are pulley driven A/C off motor shaft or seperate DC motor to drive the original a/c system. This system can’t be removed when not needed, decreases range in a big way and imploys envirenmentally dangerous gas. It mostly takes up a lot of space that is needed for more important components.

Wow, lots to consider. I’m going to be doing short trips in the winter too (early morning dropping child off at school) and preheating an electric blanket draped over the back seat which should retain heat long enough for the short drive.

It’s also been suggested that we could install an “outlet” inside the cabin for keeping the blanket (or heating pad underneath a seat cover?). Not a big fan of the electromagnetic fields pulsing through me and my child, however, so dont’ know if I’d go that route personally.