+1. My father drilled this into our heads. He's been known to exaggerate, but always told us a story of when he worked for the Highway Dept, below zero weather, and his truck broke down in the middle of nowhere. Claims he would have died if a cop hadn't just happened along at the right time.

True or not, when I lived in the midwest, I -always- kept a huge blanket in my vehicle.

>Also a good to refuel often. I try treat 1/2 a tank as empty and stop accordingly. On longer trips it lines up well with bathroom breaks.

This also helps limit the amount of water that can condense on the walls of the gas tank and wind up freezing in the pump or fuel line.

It’s possible modern cars have some countermeasures for this because it has been years since I’ve seen it happen, but an additional (potential) benefit.

A little extra reason to refuel your car sooner rather than later is that the fuel pump will be stressed more as the tank approaches empty.

Where is the additional stress from? Lack of weight from fuel above to push it through the fuel lines?

If a tank is relatively empty, it's possible for air to be sucked into the fuel pump, at which point it could air lock or cause cavitation damage. This is in addition to there being less fuel in the lines which require it to run at a higher rpm to feed the engine. The higher speeds and uneven flow will lead to higher bearing loads on the pump shaft.

Another commenter already pointed out the heat issue since the fluid acts as coolant.

Adding on to eyegor's response, in some instances, a thin layer of sediment can build up in a gas tank as well. This is normally not an immediate concern in and of itself but letting your fuel pump run too close to empty can start drawing in that sediment which can eventually clog the pump. It's worth noting this is more common in vehicles that tend to sit for a longer periods of time, like lawn mowers, motorcycles, and grandma's beige-on-beige 2008 Camry.

An in-tank pump is typically cooled by being immersed in the liquid gasoline. When the gas level drops too low the pump gets less cooling.

So you've knocked a couple operating hours off the life of something that tens of thousands of operating hours? Big deal. It'll be fine unless you run it dry for a long period but you won't be doing that because cars don't run the pump when the engine isn't running.

I have replaced fuel pumps. This involves a lot of work and often a specialty wrench. You will usually need to drop the fuel tank, which requires at a minimum raising the vehicle over 18" into air. The standard 14" jack/stands solution most motorists own is insufficient. They need to be replaced mostly because their integrated fuel filter gets clogged by the sediment accumulated at bottom of the tank, which causes the motor to fail. When the tank has plenty of fuel, the gunk at the bottom of the tank is less likely to be ingested by the system.

For my car, the pump assembly is $900. And then there's the labor charge to put it on a lift, drain out whatever fuel is in there (saving it for later), dropping the tank, and then to remove/replace the bad pump. I would guess an easy 3 hours labor.

With the average used car on US roads now over 12 years old, having the pump go bad could mechanically total some vehicles (the repair cost would exceed the vehicle's worth), so you're going to want to prolong it's life however you can.

This is in the same territory as the advice I see sometimes to make sure you don't turn the steering wheel while the car is stationary ("dry steering") because "it will put stress on steering components and shorten their life, and it will damage the tyres".

These pieces of advice are technically correct but catering for edge cases that won't affect 99% of drivers/vehicle owners. Modern cars are designed for the way people use them; people run their tanks to empty all the time.

I mean, I get your point, but I need to refill my car at some point and there are plenty of gas stations - so why not fill it up early to take care of it?

Regardless of how well prepared you are to comfortably hunker down in your vehicle, unless you're truly in no mans land without any reachable alternatives for shelter, it's best to lock up the vehicle with a note on the dash and make your way to a shelter out of harms way. Preferably by way of a route that is not along the road, even if it's more difficult.

It's never safe to be arbitrarily stopped on a road, even if you're on the shoulder. Even if you're under the impression no other vehicles will be going fast enough to not see your vehicle or cause an energetic crash. The last thing you want is to be sleeping in your stuck vehicle when a jack-knifed semi takes the roof off.

Unless I know I'm going to be in extremely isolated/rural areas, I prefer to be equipped for a hiking excursion more than a prolonged unplanned car-camping scenario. A stuck car on a thoroughfare is a very unsafe place to be, especially in slippery/poor-vis. conditions.

> it's best to lock up the vehicle with a note on the dash and make your way to a shelter out of harms way

Just a note for varying geographical locations: If you do this in Australia, you will most likely die from exposure.

Just a note for locations actually not varying that much and this is generally terrible advice: people die of exposure doing this in the US and everyone ever asked from search and rescue will tell you to stay in your car unless it is actively going underwater or falling off a cliff.

It's qualified with unless you're genuinely isolated and there's no reasonably accessible shelter away from traffic.

i.e. If you're stuck on the shoulder of a snowy/icy highway and there's a walking distance Motel 6 visible, go straight to the hotel and make your phone calls there. A road is a terrible place to camp, your occupancy has zero influence on the probability of the vehicle getting hit, though it may feel like the right/responsible thing to do - to not abandon your vehicle, it's rarely the safe choice when the stop was unplanned.

This is still really bad advice. There was a recent instance not a year ago where folks were stuck with 3 feet of snow at night on an interstate interchange. Yes there was a hotel not a mile from where they were but getting out of your car to cross the interstate in 3 feet of snow is a great way to get hit or get lost in the blizzard and get some good hypothermia. Compare this to staying in their car where they were picked up by highway patrol in a snow cat a few hours later and taken to a shelter. And its not some stroke of luck either, highway patrol knows to go look for people in their cars with the snow cat and do it nearly every year. They do not know to look for you in a drift of snow over the side of the highway.

For every anecdote you can provide of someone being careless on foot I can find multiple instances of a stopped vehicle being smashed into on a highway.

Now we even have the pleasure of anticipating Tesla Autopilot to plow into us while stopped on the shoulder, apparently made even more likely if there's an emergency vehicle present.

I didn't disagree that sometimes it makes sense to get out of your vehicle if the road is all iced up and one is worried about a trucker crushing into you due to fog. Rather I'm more refuting the following statement:

> unless you're truly in no mans land without any reachable alternatives for shelter, it's best to lock up the vehicle with a note on the dash and make your way to a shelter out of harms way

The presence of anecdotes that conflict each other is evidence that it is hard to make blanket statements like the above although I would still argue that the default should be stay in or near your vehicle during winter weather related emergencies. Also any anecdotes about AI related disasters are off topic ;)

If there is this much confusion in a online community like this about what to do in such situations, either

a more thorough study needs to be done by the Feds or

a better job communicating what definitive study results recommend, with easy rules of thumb like “if you can see the lights of a shelter on the road from your vehicle and you haven’t seen a vehicle on the road in the last hour, then walk to the shelter’.

Where I'm at in the Midwest, that light could be miles away. It's really not possible to make a one-size-fits-all recommendation.

For what it's worth, every time I've seen first responders talk about adverse weather conditions, they say to stay with the vehicle if possible. Obviously if you're on the interstate outside of Los Angeles, you probably want to get the heck off the roadway no matter what. But if you're lost or trapped, a vehicle is much easier to spot than a pedestrian. If you're lucky enough that there's helicopters looking for you, being near the vehicle is going to drastically reduce the time it takes to find you.

It's not confusion. One person is determinedly wrong. There is an easy rule of thumb: stay in your car.

You've drifted off topic, and started giving advice about "vehicle broken down on active highway" which isn't the scenario being discussed.

Yes, getting off the highway makes sense if you are in a disabled vehicle on an active highway, assuming there is something solid to shield you from the vehicles/debris that goes flying when your car is hit.

No, getting out of your car in a winter storm when all traffic is halted due to the conditions does not make sense at all.

Getting out of your car on an active highway is actually much more likely to kill you than staying in it - you instantly go from a big, strong noticeable metal cage (hopefully with flashing lights on) to a small, soft, very fragile person. People who don't see a car on the shoulder also don't see a person walking.

https://www.iihs.org/news/detail/stopped-vehicle-crashes-res...

This advice may be unique to the United States.

UK: It’s usually safest to get out of your car (using the doors facing away from passing traffic) and wait behind a barrier. https://www.theaa.com/breakdown-cover/advice/what-to-do-moto...

France: Any passengers should get out of the car on the side away from traffic and take shelter behind safety rails at the side of the road, if there are any. https://www.thelocal.fr/20210820/breakdowns-crashes-and-poli...

I'm interested in this part from your link:

>However, more than half the deaths and almost 1 in 5 serious injuries occur when a vehicle strikes a pedestrian who is leaving, working on, or returning to a stopped vehicle.

Is a breakdown of the different groups available?

• Leaving

• Working on

• Returning to

I agree that groups 2 and 3 are to be strongly encouraged against.

Group 1, choosing to leave your vehicle and stand off the road, behind solid infrastructure, is actively reducing their risk, albeit at the tradeoff of being briefly exposed to traffic.

I wouldn't recommend anyone exit a vehicle into fast moving traffic. For my comment above, I condsidered adding "if a suitable break in the traffic appears", but I decided it was overly wordy and to some extent self-evident.

> They found that 95 percent of these inconspicuous-vehicle crashes occur when a vehicle traveling down the roadway collides with a stationary one. However, more than half the deaths and almost 1 in 5 serious injuries occur when a vehicle strikes a pedestrian who is leaving, working on, or returning to a stopped vehicle. On average, this type of crash kills 300 pedestrians a year, a number that has risen by more than a quarter since 2014.

You are much safer sitting in a car on the highway shoulder than getting out of your car to walk to safety. https://www.iihs.org/news/detail/stopped-vehicle-crashes-res...

> The last thing you want is to be sleeping in your stuck vehicle when a jack-knifed semi takes the roof off.

That’s relevant to a car breaking down, but not so much in the middle of a long line of stuck traffic. The cars behind you are going to prevent anything from hitting your car at high speeds. Meanwhile getting out early can be quite dangerous.

> Regardless of how well prepared you are to comfortably hunker down in your vehicle, unless you're truly in no mans land without any reachable alternatives for shelter, it's best to lock up the vehicle with a note on the dash and make your way to a shelter out of harms way.

Nah, cars have climate control and can generate DC power for electronics for many hours at idle. Best to stay in the vehicle.

In 1972 when I was about 7 and my younger brother was 6, we were driving to NYC with my parents and got clobbered by a blizzard in Marathon, NY. So many scenes were etched into my mind - including stopping at a gas station where the attendant told us where to go to find shelter. We walked into a gymnasium where there were hundreds of other stranded folk.

But to you point, from that day on, my father kept an emergency kit in the trunk. Food, water, cash, space blankets, sweaters, etc.

I should do that too.

Yes. We had a family incident a number of years back. Stuck on a mountain pass in the cold for the better part of a day. We've also seen a breakdown in the desert, and that one was a couple days.

We always refuel before entering a risky part of travel. Never count on getting there. Make sure. And in a scenario like this that refuel could provide a days worth of heat, depending. No matter what, it's a lot more heat than driving at reduced capacity would have yielded.

Rough metric is you get 1 hour of engine idle per gallon. Some cars do better than that. And you can pulse it, warm vehicle up, make sure everything gets charged, fluids able to flow, etc... and then shut down for 1/2 hour or so in order to stretch the resource.

We carry:

-2 gallons of water

-Car road trouble kit, flairs, compressor, various tools, tape, things...

-First Aid

-Some food

And this is usually our road munchies, pet food, etc...

-Weather related stuff

> Rough metric is you get 1 hour of engine idle per gallon.

From personal experience that seems extremely conservative, although that may be the point. According to [1], a semi truck or city bus use a little less than a gallon per hour idling.

[1] https://www.energy.gov/eere/vehicles/fact-861-february-23-20...

It's totally the point. For a more precise data, I know my Ford Expedition and Chev Suburban both use about 1/2 gallon per hour, and my Honda is about 1/3.

But, when planning like this it pays to be ultra conservative. Shit happens.

Diesels use less fuel when idling.

How much? I have almost no experience with them.

A ton less.

Basically it has to do with a diesel throttling the fuel and never having any restriction on the air vs a gas engine throttling the air.

Thanks. Interesting. I understand why people get those little diesel heaters, generators.

>Rough metric is you get 1 hour of engine idle per gallon. Some cars do better than that.

I have a non-plug in hybrid, that gets almost 50 mpg consistently; I've got to experiment and extrapolate to see if it's much better. I would like to believe so.

I recently learned of the existence of:

https://en.wikipedia.org/wiki/Gasoline_heater

and wonder how efficient they are.

These seem to be mostly outdated, but I guess that they are particularly useful with air cooled engines, where a conventional heating system doesn't have coolant to work with.

You can buy diesel heaters for caravans, they seem to use about 0.6-0.7 litres/hour (eg. this sort of thing: https://www.amazon.com/dp/B07K1JJ92S/ ).

Can you even idle all hybrids? Doesn't the engine shutoff when stopped? Maybe it will turn on if the coolant temperature drops?

That's the point.

Mine does shut off, if the vehicle isn't moving and the interior temperature matches the climate control setting.

So I would think/hope it could use a fraction of the fuel by running intermittently.

It's gonna be. My normal non / hybrid Honda uses about 1/3 gallon per hour.

A Honda Civic with a D17A1 engine, at idle, with all accessories off, at 700-720RPM, reports 0.6-0.7L/h, or 0.17-0.19 Gal/h over OBD-II. Vent Fan to Full and Mixer to Hot without A/C reports 0.9-1.0L/h, or 0.24-0.26 Gal/h.

I know this is gross to talk about, but I'd also add "incontinence blankets" to this list. Specifically for being locked in traffic for this long. There are reusable incontinence blankets you can get. This way you have something designed to catch waste if you misfire.

I have these bags made for urine or vomit with a gel in it that will congealed the contents. I was stranded on a closed highway and had to pee so bad. Never again.

Why didn't you just take a pee by the side of the road?

Believe it or not, in some parts of the USA that can get you labeled a sex offender for life.

Realistically nobody is gonna give a crap unless you manage to be super distasteful about it.

Or you are disfavored for other reasons, such as race.

Tell it to the judge, creep.

Wow, didn't know that! In the UK and most of Europe it's standard practice.

It's also relatively standard practice in the US. Of course it's illegal "by the books" just like in France and some parts of the UK. At worst you'd probably get a fine if you get caught in a densely populated urban environment without a good reason.

It's incredibly misleading to say that peeing on the side of the road in an emergency could put you on the sex offenders' registry.

I'd be interested in an example of someone getting on the registry for public peeing without egregious extenuating circumstances (repeated offence next to a daycare, or something)

Not exactly an "example" but apparently 13 states have laws on the books specifically requiring registration if you are caught urinating in public. Some stipulate "repeat offenses", some stipulate "in view of a child" (The Horror!!), but most do neither [1].

1. https://www.hrw.org/report/2007/09/11/no-easy-answers/sex-of...

The same applies in the UK, but like the US you’re unlikely to get arrested unless you’re doing something more than peeing behind a bush.

There doesn't appear to be any general law specifically restricting public urination in the UK.

There are local bylaws.

And there are more serious laws for sexual behaviour etc.

This is a myth

As ridiculous as it is, this is not a myth; It varies by state whether it's required.

> At least 13 states require registration for public urination; of those, two limit registration to those who committed the act in view of a minor;

https://www.hrw.org/report/2007/09/11/no-easy-answers/sex-of...

Now, it's probably unlikely (considering a normal person is also not generally trying to be purposely seen), but not out of the realm of possibility.

In the foot notes it lists CA as one of these 13 states. But in CA "the law requires the prosecution be able to prove you willingly exposed yourself in public with the intent to bring attention to your genitals for the sexual motivation of yourself or another person. In other words, unless you were actively trying to get someone to look at your genitals while you relieved yourself in order to arouse yourself or someone else, you are not guilty of this offense."

https://vistacriminallaw.com/public-urination-laws-and-sex-o...

I was considering it (very lucky the traffic cleared), but it was a major highway at midnight that was closed due to flooding ahead, and emergency vehicles were speeding down the shoulder fairly frequently. I didn’t consider it safe for me to leave the vehicle.

In my experience, men will piss anywhere/on anything/in front of anybody. Women not so much.

Never heard of these before, after skimming amazon reviews on a few products, looks like most folks like "Travel John" and "OUMEE" brand the best. Seems useful!

Yes, Travel John is what’s in my glove box.

Btw. I replaced some years ago the blanket with a sleeping bag (warmer + can be folded/compressed better therefore needs less space when stored/hidden in the trunk), and the normal flashlight with another one which is magnetic on one side (for example so that it won't move while mount snow chains).

A sleeping bag that is stored compressed loses it's insulation properties: https://www.rei.com/learn/expert-advice/how-to-store-a-sleep...

I keep a Harbor Freight moving blanket in my trunk. It's thick for insulation, and also cheap in case you need to protect your seats after a muddy activity. I also wouldn't feel torn up about laying it down on ice if I need some traction.

And if you ever need a new one, it’s like $2

My suggestion for the flashlight is to get one that works as a headlamp. The modern LED versions are quite good, going from incredibly bright all the way down to dim but usable for days.

Magnetic flashlight is nice. If you don't have one I also suggest a headlamp.

https://www.rei.com/c/headlamps

If you get one of those vacuum pack bags you can store a blanket or sleeping bag in very little space.

I keep a few moving blankets in my trunk. Good for protecting my car/items in trips to the store, cheap enough I don't care if they're ruined, and they'll also come in handy if something like this scenario ever happens to me.

> Water is harder to store in the winter since it will freeze and burst containers if full, but snow can be melted given a container to put it in.

Emergency drinking water that comes in foil pouches seems to survive freezing; I’m not sure if it’s a requirement of the ISO standard they have to conform to for use on survival craft (I don’t want to pay $250 for the ISO standard just to find out).

I keep an emergency supply of these in my car through Colorado winter and summer, without any issues:

https://www.datrex.com/product/datrex-emergency-water-ration...

Plastic water bottles won't burst when frozen. You can get a case of water bottles for under $10.

Some will burst or leak, and they leach an unpleasant plastic taste into the water — especially in hot weather.

I change them out at the end of each year and use them to water plants. I'm very sure I'll not mind the plastic taste in an emergency situation :)

The datrex drinking water is rated for 5 years, and it tastes the same — like distilled water — 1 or 5 years in. It's nice to actually be want to drink it in a non-emergency situation if you just need some water.

Dunno why is this downvoted -- put an emergency plastic water bottle in your car during summer season and let me know if you would be able to drink the resulting mush, even in an emergency.

Greetings from Wisconsin. We have one car that we use for trips, the other is just used locally. But even for just going somewhere in town, we have a rule: Make sure you're prepared to walk a mile if necessary.

Knowing where the nearest Kwik Trip can be a life-saving necessity, if you have to walk from a dead car. Planning winter trips on high-travelled roads (avoid backroads not only because they may not be plowed, but there may be nobody along if you have trouble).

Indeed, as a cyclist, I love the paved county roads that are still in tolerable condition but with virtually zero traffic. But that's certainly not a benefit if you get stuck somewhere out there. Also, the actual location of roads can become uncertain in poor visibility or if the snow is drifting.

Emergency (foil) blanket saved my life one night when I was freezing. I carry one more often than not now. Minor space/weight penalty to avoid hypothermia.

Camelbak 3L comes with me on all road trips but I’m considering a permanent water tank in my car.

How do foil blankets work actually? Doesn’t metal foil transmit heat very well which would make them a bad blanket to trap heat?

It's actually mylar that they're made of.

https://en.wikipedia.org/wiki/BoPET

I spent a night in the woods with a Mylar foil blanket. It blocks wind and reflects the heat back to you. When it came loose I would immediately wake up cold and reposition the blanket. The thermal effect was instant on and off.

I believe besides acting as a wind barrier, the foil reflects heat internally. They would not be effective in direct contact with skin and another surface.

>Water is harder to store in the winter since it will freeze and burst containers if full

Very true. I live in a hot climate and often freeze water bottles to take with me in the summer. A full sealed bottle, even a solid one like a Nalgene, will easily break when frozen. But I've found that leaving 10-15% of space empty and cracking the top ever so slightly prevents any sort of breaks.

Leaving the bottle cracked open might not work so well for car storage though, unless it's secured upright.

Fill the bottle 75% and crush the plastic bottle a bit before fully sealing it.

Three more things:

1. Go check the pressure in your spare this week. You’ll thank me later.

2. Put a fire extinguisher in your car.

3. Get some road flares. They’re cheap and keep for a long time. They make you vastly more visible than someone holding up a phone light towards oncoming traffic.

No one kitts their car out like this in DC bc this amt of snow is basically unheard of...?

The DC area gets a "good" snow storm (≥6") about every 2 or 3 years. Typical behavior is to get a snow day the day of the storm and often the day after as well. Anyone trying to go anywhere during the storm is likely to have a rough time--the local streets won't see anything like a plow come through for a good long while, so it's not really sane to attempt to go anywhere. Even for smaller storms, only 1-2" total, shutting down completely for the day is pretty typical.

It's not so much unheard of in DC, more that we don't get enough snow to warrant heavier investment in snow removal - easier to shut down for a day or two. Anybody who sees snow in the forecast and gets on I-95 or any other major highway in the area is insane.

This site lists most major winter weather events in the DC region over the past decades... https://www.weather.gov/lwx/winter_DC-Winters

I haven't spent much time in/around DC in the scheme of things, but I would guesstimate from my experience there is some snow once or twice a year, and when it happens, everything shuts down. Businesses and government take a snow day just like the schools, as opposed to further north where a storm has to be extreme for that to happen.

That also was my experience in Richmond, VA, somewhat further south.

we have a new climate

Right, we've never had snow and cold in Virginia before.

One storm is not a trend.

I'm almost willing to bet that storms will get progressively worse in the next few years.

I think we all are willing to bet on your side.

People will kitt out their cars after this, but having lived in PA, NY and DC I can firmly say that in PA and NY I owned a brush, had water in the car and the like.In DC I legit brushed it off with my gloves.

6" was enough to just not go to work.

Interesting. The West Coast got a TON of snow in the last couple of weeks and this did not happen. The point is, over-confident and under-prepared humans are not a proxy for the evils of climate change. Let's not get too carried away. Climate change is new and it's real. Human stupidity? Much more established and reliable.

If I really kept kitted out for an incident like this I use up all my grocery room or most of the back seats. I was in my last car, but because I usually didn't take passengers.

If you optimize for space it's not too bad. Even a thin blanket of the right material is a huge improvement over nothing. That and nest things inside of each other where possible and/or use vacuum seal bags. I've typically been able to jam everything in the least convenient corner of the trunk.

You could easily fit it all in a milk crate and shove it in the back of your trunk with your spare tools.

I kept it in a crate, but took the leg room of a back passenger.

How does this logic work with electric cars; just cut the range in half?

Electric cars are apparently much better in these situations than gas-powered cars, because you can keep the heat on for hours and hours without using up much charge (or creating any CO). Don't personally know if that's true but it's what I've read.

It won't use that much charge compared to just driving around - we use so much power moving a multi-ton vehicle at highway speeds it's insane.

If you are lucky enough to have a vehicle that has a heat pump and not just a resistive heater and you use it just enough to stave off the cold, you are probably going to be in a very good shape. If you happen to have a vehicle with seat warmers, even better - heating oneself is better than heating the cabin air. ICE also have those, but you'll have to be sure to run the alternator from time to time, generally EVs will figure out when to charge the 12v system from the traction battery.

Will an EV like that outlast an ICE car? Based on the figures I'm seeing from a brief search(around 30 hours with a full tank of fuel), I think it's likely, on average. But there are too many variables.

You are completely right about the CO emissions. Can leave the heater running without worrying about poisoning.

Depends on how the heat is produced and how comfortable you want to make it, but in round numbers I would expect heating the car in a snowstorm to eat up about half the battery capacity every 24 hours. I still keep emergency blankets and I would run the heater as little as possible.

I am getting very much the opposite impression from various recent newsarticles in Sweden, where EVs are common and traffic jams due to snow, accidents etc. are commonplace as well.

Google translated a recent P4 article:

The snow weather over southern and western Sweden has had a major impact on traffic and people have been sitting in traffic jams for several hours*, reports P4 Gothenburg.

A major problem has also been electric cars abandoned on the E6 by their drivers. The battery runs out when there is so much heat in the car.

- We will be able to salvage(tow) a lot of electric cars that were on the E6 during the night, says the Swedish Transport Administration's road traffic manager Mikael Salo and believes that this is one of the shortcomings with the new cars.

Good advice. I also keep a "Portable Car Jump Starter" in the trunk. These days they are basically big batteries (mine is ~3100mAh at 12V apparently) and they come with USB plugs and a built-in flashlight... Handy if you need to recharge your phone in a pinch.

I hope you're off by an order of magnitude on that current rating, or it might not deliver the goods when you need it...

He didn’t give a current rating. “mAh” measures energy storage, and 3100mAh is enough to jump a car a couple times.

Jumping a car doesn’t take a lot of energy. But it does take a lot of power (and therefore current). Small Li-ion car jumpers can be surprisingly capable.

I jumped a stranger’s car with my 66.6 Wh battery the other day. DC output 12V/10A. Peak current 2000A. Battery is still ¾+ full. Haven’t tried charging a phone from it though.

I have actually used this thing several times to jump a car. It works great.

Those are great to have. I will say that 3100mAh is pretty low and wouldn't even fully charge most smartphones. 20kmAh batteries can be purchased for less than $100, and 10k-15k mAh for less than $50.

A good idea to have just in case. :)

Someone already mentioned this but I want to clarify that mAh alone is not a full measure of capacity.

OP mentioned his mAh rating in 12 V but you’re comparing it to Ah ratings in 5 V. OP’s battery should be able to charge a full smartphone fine.

Also, most of those 10-20k battery packs won’t be able to jump start your car because they have greater capacity but cannot provide power quickly. There are high capacity battery packs that do jump start but they’re over $100 from the last time I looked.

I purchased a 20,000mAh “jump pack” for $120CAD two years ago to use with my boat. I’ve jump started it with no problems, and this was a Mercruiser 350. I’ve also boosted a car and a truck in -25C weather. They work great, are super portable and only weigh 2-3lbs.

Caveat - unlike a standard battery booster pack (lead acid), lithium battery does not take kindly to freezing temps, so it is useless to keep it in the car over winter. I wouldn’t expect to be able to start anything in the middle of winter up here unless it was kept indoors at room temp.

Spoiler, it works.

I use a lithium booster battery pack for an old car I use, and have used the battery pack to jump-start my car multiple times on a freezing-cold day (sub 10f) while trying to locate a store with a new car-battery in stock.

Amp-hour ratings only should be adjusted for voltage if a DC-DC converter is used. If the jump starter uses a cheaper linear regulator, the amp-hour ratings remain the same. (The excess energy is discarded as heat.)

I had a cheap one 5 years ago that was able to jump start a car. The instructions said to leave it connected to the battery for 30 seconds before trying to start it, so I guess it's more a portable battery charger than a jump starter. For sure if you disconnected the 12V battery and only connected this it would not work.

Since you are probably not talking about kilometeramperehours, might want to fix the unit to just Ah.

Battery packs are usually marketed with their capacity in milliamp-hours. I thought the 15-20k mAh made it pretty clear that we were taking about a 15000-20000 mAh battery pack.

They are, but SI prefixes are always combined, not used together. 15k mAh is just wrong. The correct way to write it is 15Ah.

I believe the k in “15k” is a suffix and thus not beholden to the rules of SI prefixes. In this case it is used as shorthand for “thousand”, and this usage is prevalent even in countries where SI units are not commonly used.

Insisting on changing 15k mAh to 15 Ah is the same as insisting on changing 15000 mAh to 15 Ah - which seems to be a matter of personal preference more than anything.

Mind you that's 3100mAh at 12V. That's roughly 7400mAh at 5V (USB voltage).

That is assuming a DC-DC converter. 3100 mAh is 3100 mAh regardless of voltage if the charging functionality uses a cheaper/simpler linear regulator.

Indeed! That's a good point. If it uses a linear regulator, I guess the thing would produce quite a bit of heat when drawing power from the USB ports - the extra energy would just be converted into heat.

Is possible battery damage or malfunction due to the heat in a car a concern?

> Water is harder to store in the winter since it will freeze and burst containers if full

In my experience, filling a PET bottle to the brim with tap water and freezing it is fine. The bottle won’t burst, but, I guess, be stretched a bit. Some water will be forced out when you open it, but that’s all.

I use this on hot summer days. Freeze water overnight, take it with you, and you’ll still have cool water in the afternoon.

Warning: I haven’t tried this in outside temperatures. Those can get a lot lower than you garden variety freezer unit inside a fridge.

Keeping some matches handy and lighting a tea candle in the car is surprisingly enough to keep you warm overnight, too.

Also: flashlight and a tarp.

Specific recs:

Sleeping bag: https://www.walmart.com/ip/Coleman-0-F-Rectangular-Sleeping-...

Warm gloves: https://www.amazon.com/1927KW-L-1-Premium-pigskin-polyester-...

Warm hat: https://www.amazon.com/Minus33-Merino-Wool-Ridge-Beanie/dp/B...

Headlamp: https://www.amazon.com/Vont-Flashlight-Batteries-Headlight-H...