110V ceramic heater elements
 

Hello,

I'm in progress of converting a car to electric. I need heater because of climate here (worst case around -30C, or -22F according to google, hehe). I'm using 96V system. Here in europe we have 220V devices. 1000-2000W heaters are cheap enough but those are rated at 220V. If I tear one apart and apply 96V DC into it, it won't produce much heat I guess.

I thought about 110V elements, but can't find any cheaply from eBay. I actually need only elements, not the full plastic case heater. I see lots of US webstores have them available, but none of them does international shipping.

I suppose 110V elements would do the trick if 96V DC is applied to them. Right? At least much better than to apply 96V DC to 220V element. I also believe I need two of them connected to produce some real heat to keep front windows clear.

Any opinions? Any help with finding 110V ceramic heater elements?

Hello Mora,

Do you have Wal-Mart or Home Depot or any other American discount retailer near you in Finland? You may be able to get them to ship a complete heater to a store near you. Electric heaters here in Minnesota are pretty cheap Wal-Mart has two for under $25 US. I'm not an electrical engineer but, aren't electric heaters just big resistors? Could you hook two 220 v elements together in series to make it work at half the voltage? WiKipedia has the formulas if you search electrical resistance. It's too early in the morning (7:00 am) here for me to figure out. That's all I can think of to do. Good luck with your project.

Thanks for the good wishes.

Unfortunately we don't have Wal-Marts of Home Depots here. We have some similar stores but those don't carry anything rated for 110V.

I'm no electrical engineer either, but if I hook two 220V heaters in series and apply 96V, they both run at half voltage if resistances are equal (48V per element, even lower amount of heat). Connecting them paraller gives both 96V, but it is still way under what I want.

I noticed I could open an account for some online service and get a "valid" US street address. I could order anything to that address and they would send all the stuff to me. But that costs even more than if x-mart would ship directly to me.

I don't know anything about anything, but it seems even a 220v ceramic heater should work fine in a 96v setup because of the whole "resistance increases as temperature increases" thing. Yeah, I'm a real electrical genius:p Anyway, here's a video of what Gavin did with a 220v heater (though he was running 144v, I think 96v should still work):

Installing the Heater

Heheh. Thanks for the video link. I've read the whole conversion story and watched every video through. That's where I got the idea of ceramic heater in place of original heater core. If you take a look at the text under the video, at the very bottom he says one element delivers only "warm" air during cold mornings. He recommends the same thing as I think: a 120V (or 110V, hehe) element or two elements paraller. I think he means two 220V elements in paraller, but I'm going to use two 110V elements in paraller.

I also think that element doesn't work at its full power if lower voltage is applied. If so, element works like described (resistance increases as temperature increases and this limits current). If so, resistance of 1500W 220V element can be calculated. Same resistance with 96V voltage results in ~400W power. Boo.

Could someone of you living in the US get me pair of really cheap ceramic heaters, disassemble them and then send ceramic elements to me? Way cheaper than shipping two full heaters, which are going to get taken apart anyway.

Ok, this is perhaps where my lack of electronics will become apparent, but I thought that there was no internal difference between 110v and a 220v ceramic heater; this would be because it doesn't care how much voltage is going to it since the resistance varies based on the amount of heat produced rather than voltage. This would explain why, in contrast, coil type heaters have resistors in line, whereas ceramic do not. If however, there is a difference between a 110v and 220v ceramic heater, couldn't you compensate by using two in parallel 220v elements to be the equivalent of a 110v heater? Ok, I'm going to shut up now because people will start worrying for my life that I know so little and trust my life to an electrically powered car.....:p

That's the first thing that came to my mind, but after some thought I understood that I got it wrong. Using two 110V heaters in series with 220V voltage would work, but not the other way around. But then, I'm just the next member here without too much understanding of electricity, who is telling Mora what won't work.

But here's an idea (don't know if it'll work): Someone with a 110V ceramic heater at home should check its resistance and post that along with the rated wattage. Then maybe Mora could find a ceramic 220V heater with similar resistance and try to use that.

Or someone who actually knows something about electricity could post so we don't all kill ourselves (and each other).

Hehehe, yes. I'd prefer someone wiser chiming here too.

I can put two 220V in paraller. But I don't have space to put 4 of them paraller. I want 2x 110V. Lots of heat if necessary. Big amp draw too, heheh. But I think heater doesn't need to be on all the time when driving.

Resistance is very low when element is cold. Maybe too low to be measured. If element is heated to its full, resistance should be higher and readable. Touching the AC powered element with multimeter might be scary though.

I will definitely experiment with both 110V and 220V elements if I happen to get 110V one. Also if I used higher voltage, lets say 144V, I wouldn't have to worry that much about 110V elements anymore. But rising voltage isn't an option for me right now.

.

Let's throw in one useful fact.
 

OK, here's the fact,

If you run any common electric resistance heater at half voltage (eg rated 240V, operated on 120V) you will get 1/4 of the rated wattage out, as heat. So, a heater rated at 2000 watts, operated at half voltage, will only produce 500 watts of actual heat.

Voltage matters. A lot.

So, good observation on your part, that running a 220V heater on 96V doesn't get you much. Less than 1/4 of rated wattage in fact.

Your original plan to get a 120V heater to operate on 96V is a good idea, you just have to find one.

Can't help you with that part, very sorry.

troy

Good info.

So I suppose maths go like this:

P=power, U=voltage, I=current, R=resistance

P=U*I -> I=P/U -> 1500W / 220V = 6,82A
R=U/I -> R = 220V / 6,82A = 32,26 Ohm (max. resistance I assume, for that voltage)

then, if we use 96V instead of 220V
I=U/R -> 96V / 32,26 Ohm = 2,98A
P=U*I -> 96V * 2,98A = 286W

Oh. For 220V element and 110V operating voltage power would be 375W, 1/4 of full power.

But then. 1500W 110V element with 96V:

R -> ~8 Ohm
P -> 1150W

Much better. One element produces more power than two 220V put in paraller. Two units provide twice power if put paraller.

Buy a 220v ceramic heater and take it appart, you will find a ceramic chunk in there with heating wire wrapped around it, messure how long that wire is, divide it by 220 and multiply it by 96 and that will tell you how long of chunks of wire you need to cut, the ceramic acts as a high temp heat sink to help spread the heat so you can pull more heat out of a smaller area.

Last time I opened one I saw no wire. It's a metal-like element. Do you mean I should cut the element?

So, if you solder both ends together, then connect that to one lead of your power source and the other lead in the middle of that wrapped wire, you will have two 110V volt heaters in parallel, right? Which would be exactly what Moro is looking for?

with how cheap normal 110v heaters are, it wouldn't be worth messing with that (possibly causing a weak connection).

Amazon.com: Lasko 754200 Ceramic Heater with Adjustable Thermostat: Kitchen & Dining: Reviews, Prices & more
They won't ship to you??

I had no idea 110v was not available in Finland, seems so standard. Even in Europe it's 50Hz but at least it's there. Around here you could get one of these for $5 at a garage sale.

Have you checked out the inline water heaters? With one of those you can use the car's original heater coil setup. This might give you an idea:
EV Source - 12V Electric Heaters

Prices there seem at least 3x what they should be but they look ready to fly. If you go that route then check out fish/marine supply stores.. but there will be a time lag, personally I'd go with the ceramic instant-on.

Yes, only don't solder, crimp as solder will melt and as others have stated you would want a little less then half the element as you are running 96v instead of 110/120 (half of the 220v his heater is designed for) so you have 2.2 times to much element.
Last fall at the Electric Auto Association meeting they were talking about adding electric heat to electric cars and a number of people who were running at 72v had cut their heaters appart like this and said it worked well, one who was running 96v and had a 120v charger had left his heater together so he could heat while charging and while driving with the same heater.

Funny thing, I was browins amazon.com and looking at the very same product you linked at the same time as I received a thread reply notification. I found the same product from amazon.co.uk, which is located in europe, but they carry only 220V version. Thanks for the suggestion.

I'll see if amazon.com ships to me. Would be good if they did.

Yes, I've taken a look at those. Heat isn't as instant as with electric heaters and there is a need for pump too. I bet that system is more inefficient overall when compared to electric heater.

Yes, they ship to my address. With expense of 83$. Ouch. No deal, at least for now.

I placed a wanted-ad of two elements to sales section. Link to ad here. I'll try to find someone to find cheap heaters, disassemble them and send only elements to me. Should be way cheaper even if I paid some extra for it.

Yes I would be willing to help you out. I can get you a couple of heaters take them apart and send you what you need.

If your willing to foot the bill for the heaters and shipping.

You don't even have to cut the element. Just solder a tap into the center of the wrapped wire. That gives you a power feed, then ground both outer ends of the element. Instant ~110 heaters, in parallel! Well, probably not perfect, but since you're giving them well less than 110v, a little bit off on either side will be ok - the side that's shorter will just operate closer to the rated current and the longer side will run slightly under power, and not quite as hot.

I played a bit with heating wire back when I rode a bike - I made some gloves that had bits of heating wire glued to them (using the puffy fabric "paint" you see at craft stores). They would heat my hands up pretty well, but I didn't get enough wire in the finger areas to really do what I wanted. Of course, risk with 12v is pretty low, but by keeping everything in the stock case and just adding a new power lead, you reduce risks.

My Citicar has a 48 volt pack. I bought a cheap ($10) resistive heater with a coil element. I cut the element in half and paralleled the two halves. I replaced the 120VAC fan with a 48VDC computer rack fan.

At 48 volt it will put out enough heat to run as a defroster, but not quite enough air volume to act as a heater. But it does heat some. Using the original heater at 96 volts would probably work somewhat better.

I leave the installed heater switch on at full heat, as the increased amperage (about twice the original 120v amount) will likely weld the switch on if it is changed while powered. I use a solenoid to switch the 48 volts on and off.

Here is a picture of the heater coil with the element cut in half and paralleled, with crimp connectors.

Now I see. That might not work with element-like heaters though. See attached photo for what I mean. Your heater element doesn't look the same.

Of course. I'll send you a private message.

Hopefully you'll be able to get 120v ceramic elements - They should work OK at 96v without modification. They'll be a bit cooler, but you could parallel two or three elements to raise the temperature, and turn on/off elements as needed.

International Price Calculator

As you can see, even though I can buy 1500watt ceramic heaters in the 5-$10 area shipping in the last 5 or 6 years has gotten so high you probably won't accept the cost of shipping.

If you can find someone here willing to send you one of the cheapies from biglots or a junk store/pawn shop you still will probably have to pay $40-$60 shipping

Cheers
Ryan

No worries. Only large envelope is needed for shipping of bare elements (I believe). 30 oz of large envelope costs less than 30$ to mail here.

The other thing to remember for heating is that you need a really good switch to turn the heater on and off.

We are dealing with DC power and a fair amount of amperage. Seems like most guys are using solid-state relays for heater controls.

Also, you could use a locally purchased heater (that runs at native voltage) for preheating your car while it is charging. It can be set on a timer. That warms the whole interior of your car, and makes it much more comfortable.

All the new commercially built electric cars coming out are going to have electric pre-heat and pre-cool.

You can also go to a place that sells ceramic and pottery supplies, they will sell you bulk heating element, most likely a better quality then is in little heaters as well.

Our post office has cracked down on putting stuff other than paper in envelopes, when you do they charge you parcel post instead of 1st class envelope.

Maybe envelope is not a correct word. I was thinking of bubble-wrapped envelope or something similar. I hope you can put something else inside of bubble-wrapped envelope than plain paper. Makes mailing small things safer and cheaper.

Here they use word maxi-letter. They have a piece of plastic with rectangular hole imitating a small mailbox. If envelope fits through the hole then it is all right. Weight determines the price.

Two elements shipped in one package was a bit over 14$. Not bad for an international shipment. Takes more than two days to arrive though, hehe.

Yes, that's a must here. ICE-cars have separate electric engine heaters and same cord goes inside the car too. So when car is plugged into AC outlet the engine heater operates and separate electric heater warms interior. Most residental parking lots have a separate AC outlet box with adjustable timer for each parking spot. Plug the cord between your car and box, set timer and before you drive again unplug the cord. Car starts well even if it was -25C and it is all warm inside. So very useful (a must, hehe) here.

I wonder what these temperatures do to DC motor in a long run. Not everybody has a garage and cars need to stay under bare sky. Last winter there was a 2 week long cold season with less than -25C every day. Maybe I should put a heater with fan blowing hot air to motor under the hood, heheh.

The grease in the two bearings in the motor is big thing to be affected by cold other then that the resistance of the motor will drop a little as it gets colder but you will most likely never notice a change the change you will notice will be in the batteries with the cold and that is why you put battery heaters in.