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As I sit trapped in my apartment, unable to go grocery shopping because of my frozen-solid car battery, I can't help but think "this sucks". So I came up with a solution that I will never be able to afford or implement: a methanol powered battery tender. It's pretty simple - mount a small methanol
fuel cell next to your car battery under the hood, or in the trunk (or in the wheel well if your car is a POS). Before the weather drops below zero just fill a reservoir with methanol and you are done. Overnight the DMFC will generate electricity and trickle charge your battery to keep it alive. A convenient byproduct of DMFCs is that they produce heat. The heatsink can be mounted up against the side of the battery to help keep it warm, or even function as a block heater. If the temperature gets too high a switch turns on a cooling fan.
Why would somebody need this? A lot of people living in apartments don't have access to electric outlets for block heaters or battery blankets. Even brand new batteries will freeze solid at a certain temperature. Currently, no other /practical/ technology exists that can charge a car battery or keep it warm without cords. Solar doesn't provide nearly enough power, and a gas generator would be very impractical. Methanol costs a bit, but not as much as the fuel and maintenance costs of running your car all night (not to mention the environmental impact).
I actually thought about making this my next DIY project, but the cost and engineering challenges are a bit beyond me.
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In general the car battery is probably not dead; it is just too cold for the relevant chemical reactions. So, a more efficient use of the methanol would simply be to burn it to make heat, to warm up the battery shortly before you try to start the car. There should be no need to charge the battery if it ordinarily holds a charge OK. |
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it's called a battery blanket. if it's that cold then you need one. What is it 30 below? |
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I don't know where [Matt] lives, but outside my house right
now it's -28 with windchill. So, yeah, it is 30 below outside,
and both of my trucks are plugged in warm and cozy for
the night. Fortunately, I have external outlets and parking
privacy (every kind of privacy, actually). Others, as
pointed out in the Idea, do not enjoy such luxuries: |
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// A lot of people living in apartments don't have access
to electric outlets for block heaters or battery blankets. // |
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It's a balmy 1 right now, up from a wind chill of -35 (F) a couple nights ago. I have been trying to think of ways to keep my battery warm for a while and all I can come up with is lots and lots of hand warmers, a methanol generator, or the "nuclear option", nuclear power. |
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In the grand scheme of things there's nothing particularly significant about the water-ice temperature range... so why aren't there cold temperature batteries, ie: electrochemical reactions which are comfortable in minus degree weather. |
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There are deep cycle batteries that are made specifically
for sub-zero weather. I thought about getting a pair for my
deuce, but they're very expensive and I'd still need a
regular pair for the summer. |
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// wind chill of -35 (F)// For the record, wind chill
won't make any difference to the battery. |
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True, but it is a significant factor to the person who has to
go start the truck in the morning. |
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// why aren't there cold temperature batteries, ie: electrochemical reactions which are comfortable in minus degree weather. // |
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Most battery technologies use water as the electrolyte. Cool it, and ion mobility and reaction rates drop off very fast. |
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Lithium-ion batteries with organic electrolytes are less prone, but are still temperature sensitive. The introduction of 48V vehicle electrical systems using LiFePo technology will be an advance in this area. |
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A compressed-air starter system is a bit more resilient. |
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There are a number of problems around "super cold starts" of internal combustion engines. Lubricating oil thickens; diesel waxes up, gasoline is less volatile (although less of a problem with fuel injection systems). Component tolerances change significantly. Drive belts embrittle. |
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The best schemes use a sump heater or a circulating coolant heater, along with a low-output tape heater to keep the battery warm, and pure glycol in the cooling system. Air-cooled engines are superior in this regard in very cold conditions. But all these fixes require an external source of electricity. |
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^I just found it easier to move to Oz. |
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We don't have this sort of trouble. You have my
sympathy, to the extent it's your fault that you live in a
part of the world that's colder than a deep freeze for half
of the year. |
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It's not my fault somebody said "hey, this endless expanse of frozen tundra looks like a great place for a university!" |
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Of course. Cheap land and "expendable" students. Why
not? |
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What you need is a heater powered by an exothermic
chemical reaction that would produce a fair amount
of heat for several hours, and not be expensive to
refuel. |
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Charcoal briquettes would work reasonably well; fairly
cheap, produce a good amount of heat, but I
wouldn't like the idea of such combustion under the
hood of my car. |
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How about an electrically powered heater? I mean that big
battery is just right there. |
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How about building a garage … ? |
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A heated garage (or even a heavily insulated garage)
significantly lowers the lifespan of a vehicle in a winter
climate. |
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I'd say what you need is one of those old liquid fuel
hand warmers and a blanket. But since you have DIY
in your name and if you use your vehicle reasonably
often, the blanket alone and some selective heat
transfer would work well. I assume a battery is
probably a good heat sink. So I'd say find a suitably
sized Igloo cooler, put the battery inside and then get
some copper tubing and small pump controlled by a
thermostat. If my cooler can keep ice from melting
for two days, yours should keep your battery from
freezing if first heated to say 100F first. For a long
term storage get an alcohol or cheap camp stove to
heat the coolant outside the cooler. |
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// A heated garage (or even a heavily insulated garage) significantly lowers the lifespan of a vehicle in a winter climate. // |
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Hmm, I wouldn't have thought of that. Is it because of condensation when a cold car is put away in a warm garage, and/or having more freeze/thaw cycles? Is rust the major limiting factor on car's lifespan in this situation? |
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//A heated garage (or even a heavily insulated garage)
significantly lowers the lifespan of a vehicle in a winter
climate.// |
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Can you please explain that statement? It's counter-
intuitive. |
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Ice doesn't cause rust. If you park your car in a heated garage the ice and salt will begin to melt and rust out the fenders. I'm not worried about rust though, as my car has paint that is thicker than some cars' sheet metal. |
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a) Heated garage melts water which flows into cracks in the paint. |
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b) Outside weather freezes the water which widens the cracks |
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d) during the winter there's plenty of salt on the road as well which makes the water even more corrosive than usual. |
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If your car will start at 0 degrees Celsius or just below, you could use the latent heat of freezing water to protect it. |
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Place containers of water around your car's bonnet. Then insulate as well as is possible. Expediently, cover the hood with an old blanket. |
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I think that might even work. |
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If the water is all ice in the morning, you need more water containers and/or better insulation. |
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// Can you please explain that statement? It's counter-
intuitive. // |
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Others have mostly explained it for me, but nobody has
gone into pedantic detail. |
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The worst hazard is road salt. When you drive on icy,
slushy, salted roads, your vehicle collects a great amount
of ice and salt residue, especially in the undercarriage and
wheel wells. If the vehicle lives outside, it's not much of a
problem, because it just stays frozen there until you swing
through the automatic car wash and blast it off all at once
(which a smart vehicle owner does two or three times per
winter, or whenever the tempurature threatens to rise
above freezing). However, if you park your car in a heated
garage, the coating of dirty ice and dissolved salt residue
melts very slowly, working its way under loose paint,
pooling in cavities and crevices, and gradually corroding
just about every steel component of your beloved ride.
Every time you drive, you collect a fresh layer of this
insidious solution, and every night while you sleep it eats a
little more of your car. |
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Another culprit, our old friend the thermal
cycle, is even sneakier. The different materials used in
various components of your vehicle--plastic, rubber,
copper, steel, aluminium--all expand and contract at
different rates as they change temperature. Fittings and
fasteners
gradually loosen, fluid lines become brittle and crack,
resistance welds deform and split, etc. The cylinder
packing around the shaft of shock absorbers (dampers)
comes loose and oil begins to leak out. Delicate electronic
sensors crack and fail, festooning your dashboard with a
veritable christmas tree of idiot lights. Even the various
fluids in a vehicle can suffer (slight) detrimental effects
when subjected to a daily warm/cold cycle. |
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Most denizens of the Great Frozen North know that the
best thing to do is leave cold cars cold. The thermal stress
caused by normal operation is hard enough on the poor
beasts; why make it worse? |
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That makes sense. If I ever take a vehicle on the beach I
make sure I wash all of the salt water off it before it gets
a chance to begin corroding the metal components. |
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