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> it's normal for the battery to die if you don't drive it for 3 days I've heard this nonsense a couple times now. I was incredulous at first but everyone seem

by kccqzy 4y ago

> it's normal for the battery to die if you don't drive it for 3 days I've heard this nonsense a couple times now. I was incredulous at first but everyone seems to say this. What are anyone's suggestions for a weekend-only car? (I bike to work so I don't need a car on weekdays.) Trickle charge the car battery on weekdays?

stocknoob 4y ago
Or disconnect the battery (you’ll have to reset the clock, etc., which is annoying).
- ChuckNorris89 4y ago
  Not great advice. Most new-ish cars also store the dinamic engine calibration data in ECU RAM so if you disconnect the battery you can find your engine running harsher next time. So are the values of the headlights auto leveling system and other stuff. You're also risking to reset the radio/media unit security code (on cars that aren't too new but also not super old), which if you got the car second hand and the former owner didn't save the piece of paper it came with and give it to you, tough luck unlocking it.
  - stocknoob 4y ago
    Not ideal to cut power to the entire car, but that happens anyway on every battery swap, no? If you want to get fancy you can isolate the exact fuse and switch just that: https://www.ebay.com/itm/175668177479 https://www.ebay.com/itm/175668177479 Thinking more, given how common parasitic drains are, carmakers should have all non-essential fuses in a separate subpanel section that can be easily switched off/diagnosed.
    - BenjiWiebe 4y ago
      No. Good automotive mechanics plug a little 12v power supply into the OBD port before replacing the battery, to keep the ECU/radio RAM powered.
  - pvaldes 4y ago
    There are systems that can be attached to save the parameters from the car before you disconnect the battery or even to provide electricity to the car while the battery is being checked in another room. Not common to find and most people don't need them, but they exist.
peteradio 4y ago
It's nonsense! If a car is dying after not being driven for several months, ok fair enough. If after several days a particular year make model dies it deserves a recall!
maccard 4y ago
No car I've owned in the last decade has actually drained in a few days. Any car that does has a problem.
- _ea1k 4y ago
  I have this problem, but it really only becomes an issue when a few days becomes a few weeks. Do that a few times and the battery will lose capacity too.
  - maccard 4y ago
    Weeks, sure. 2 weeks is probably on the lower end of acceptable though. My car is often left for 2 weeks and is completely fine, but most of the time it's weekly.
_ea1k 4y ago
Yes, they make battery tenders that are specifically for this. They'll trickle charge when needed, but also not charge at all when the battery is at the right voltage.
tadfisher 4y ago
You can drive a car from the 90s before they started shipping alarms and keyfobs in every vehicle. My 1995 Miata draws just enough power to maintain the clock in the radio, and it starts just fine after sitting for 6 months (it's not a winter car).
- olyjohn 4y ago
  My 2000 Ford Explorer has all kinds of electronics and modules from the factory. And even my crap I added in... I leave my Qi charger, ham radio, Bluetooth FM transmitter all running and plugged in, and I can come out a week later and the battery is still not dead. And when I'm camping I run a 12v van all night long. Truck starts right up every time. I don't get what would be draining more power than that in a more modern car. You'd think they'd be more efficient at not wasting juice.
  - BenjiWiebe 4y ago
    A modern car is supposed to have single digit or less milliamp drain, according to a random car mechanic I know. I'm a mechanic but not automotive. That's after being off for 30 minutes though. Some things stay on for a while.
kybernetyk 4y ago
There's battery kill switches you can install onto the battery pole to effectively disconnect everything from the battery. This should work for older cars. For newer ones you may experience hiccups like reverse camera not working for a few hours until it has re-paired itself with the head unit.
- SoftTalker 4y ago
  Also the engine and transmission computers may go into "learn" mode if they are cold-starting having had no power for a while, and so you may have stuff like a wandering idle speed for a little while.
- illumin8 4y ago
  This really wouldn't work for any car made in the last 20 years. Most of them have anti-theft systems that require you to put in a PIN to use your stereo if it ever gets disconnected from the battery. I suppose you could type that in every single time, but there are other computers like your automatic transmission management that learn how you drive, etc, and might not like to get reset every day.
  - windowsrookie 4y ago
    This is false. I have owned many different cars from the last 20 years and none of them did this when you disconnected the battery. A quick google search shows that it's Hondas that do this, not "any car made in the last 20 years".
tecleandor 4y ago
Really nonsense. It's true it might be more common due to all the additional modules and computers cars have now. If one goes crazy, it might drain your battery. But this is only in case of a failure. Edit: cold weather can accelerate that. If it's 'weekend only', battery should be no problem. If sometimes you leave it a couple months unused, that might be a problem. Depending on how ready you would like to be when you're going to use it, or the access you have to your car (is it far away or in your garage?) you could add a connector for a battery charger/maintainer (some of them have accessories for plugs you can leave permanently, see the NOCO GC002 for an example), and/or add a battery switch to easily disconnect the battery. Warning: your radio might ask for a security code if it loses battery connectivity. Be sure you have it.
- red-iron-pine 4y ago
  > Edit: cold weather can accelerate that. My Honda HRV dies anytime it gets below -7C. Outside, inside, driven a bunch a day or two before -- once it's cold that battery taps out. Probably a vampire drain but I suspect it's just a small battery. My old 2013 Mazda 3 starts in -25C without fail.
  - Scoundreller 4y ago
    Could be a weak starter (and or the combination of that, a weak battery and maybe even bad ground straps).
- ghaff 4y ago
  I don't have extensive experience with my current car bought last summer but 2 weeks in warmer weather definitely wasn't an issue. I agree colder weather is always a bigger issue and at 1-2 months I'd definitely be thinking of a trickle charger if at all possible. An older car I didn't drive in the winter would definitely end up with a dead battery if I didn't keep it on a charger.
  - EricE 4y ago
    AGM batteries are a lot more durable than regular lead-acid. They can cost a bit more but for me the longer life, more resistances to issues if you do run them all the way down and their sealed, maintenance free nature makes them the first thing I swap out. Optima used to be the only commonly available batteries but Costco, for example, has AGM equivalents for just about every battery out there - you may have to order it and wait a few weeks. They were also the original batteries used in Miata's since they give off a lot less hydrogen when charging. Since the Miata battery is in the trunk, and all lead acid batteries give off hydrogen when charging, and hydrogen in an enclosed space can also be rightfully called a bomb, having less of that is a good thing!
FartyMcFarter 4y ago
I didn't drive my 2019 Mercedes for months during the pandemic and the battery was fine. It did give me a warning when I restarted driving it (I guess the battery was starting to get low-ish), but it immediately fixed itself.
KMnO4 4y ago
You should see if there are carshare options around you. Even if you’re spending $50/weekend (which is a fair amount of driving — Communauto is as low as $3/hr), that’s still quite a bit cheaper than owning a depreciating asset with lifetime maintenance costs (not to even mention insurance and fuel).
- ryukafalz 4y ago
  Oh do I wish there were carshare options near me. Just moved from Philadelphia where ZipCar seems to be the only remaining contender, and you're lucky if there's one within a half hour's walk in the part of the city I was in. It's even worse in the town I moved to. There used to be a few at the nearby train station, but those seem to have disappeared. (This reminds me, I should go cancel my membership.) I'm jealous of the carshare options that seem to be available elsewhere. If it were as easy here as in this NJB video, it'd be a no-brainer: https://youtu.be/OObwqreAJ48 https://youtu.be/OObwqreAJ48
- ambicapter 4y ago
  "You will own nothing and you will be happy"
  - tsgagnon 4y ago
    This must be the new astroturfing attack against concepts like public transportation. I've seen this phrase pop up too frequently at this point for it to be organic.
    - EricE 4y ago
      The simple may see it as astroturfing, others see it as an observation by those paying attention. I'm now living in a house I own without a mortgage because 20 years ago I bought a house and didn't rent. Utilities and property taxes are my only expenses. Yes, there is maintenance but if you don't think that's also factored into rent you are beyond delusional. Landlords aren't going to lose money out of the goodness of their hearts. I haven't had a car payment in over a decade because I take care of my stuff. The car goes in the garage; I don't fill my garage with a bunch of useless stuff I will likely never touch again (or pay someone else to store it!). Common sense stuff like the above, sadly, isn't common sense any more - so hence pithy phrases like own nothing and like it. A modern day emperor has no clothes, if you will.
heleninboodler 4y ago
Yeah, if a mechanic told me having the battery die in 3 days was normal, I'd stop going to that mechanic.
- arscan 4y ago
  I did that for the exact same problem on the same model car earlier this year, but gave up after trying a few places that all said the same thing (including the dealer). Glad to see this post though… now I know I’m not the crazy one.
  - bityard 4y ago
    I would expect a _good_ car (no maintenance issues, new gas, newer battery) to go at least a couple months without being driven and not have any issues upon starting it up. The average car in average condition should go around a month without being driven. Anything less than that either means a battery nearing the end of its life, not getting charged, or a parasitic draw somewhere.
    - illumin8 4y ago
      We have a 10 year old Honda Odyssey that we keep just for long road trips and it has gone 3-4 months without being driven with no issues. I usually do try to fire it up every 1-2 months just to make sure the battery gets a charge and to avoid long term storage issues around oil and belts and other parts that degrade.
      - elzbardico 4y ago
        I would also make sure to use a fuel stabilizer like Pri-G, gasoline in a gas tank, depending on your climate can degrade pretty fast.
        illumin8 4y ago
        Thanks, that's good advice. Luckily we've burned a tank or so every road trip (every few months) but I was wondering about that and whether it was good for gas to sit so long.
chrisdhal 4y ago
My wife drives about once a week, probably less on average. She has a 2013 Honda CR-V, only 15,000 miles on it. We live in Minnesota, so have cold temps, but the car in a garage. The car always starts. We've replaced the battery once just due to longevity. Every 3 days? No way.
- yurishimo 4y ago
  15k miles on a 2013 CR-V? Enjoy the last car you'll ever own! I assume you know this, but some of the maintenance items for that car are 8 years I think; worth checking the manual to find out!
  - rconti 4y ago
    Tires should be first on the list!
  - chrisdhal 4y ago
    Haha, yep. She refers to it as the literal "just driven to the grocery store by a little old lady" car (because it's basically that and Home Depot). She even got the lowest trim level (on purpose) so it doesn't have anything fancy (no BT radio, no keyless start, no big display, etc.). Good point on the maintenance. I do get the oil changed, again more by time than distance, and I'll look up the other stuff now that you've mentioned it, thanks.
rconti 4y ago
I try to keep my cars on trickle chargers (Noco Genius 5 in my case) when not driven regularly, because regularly killing $300 AGM batteries gets expensive. That said, I'd expect most cars should be able to manage, say, 2-3 months. It's when I exceed 4 months with some regularity that battery life starts getting sketchy. If you're driving the car every weekend, I'd expect that should be plenty. Note that fancier cars with more electronic features don't do well when only driven short distances. If you only drive 2-3 miles at a time, you might be discharging the battery faster than you're charging it.
aksss 4y ago
Table for reference: https://homebatterybank.com/how-fast-will-a-car-battery-drain/ https://homebatterybank.com/how-fast-will-a-car-battery-drai... That said, at between like 0F and -10F, I'd be intentional about starting that car every couple days. Below -10F to -20F, I'd start it each day. Below -20, I'd consider bringing the battery inside for the night - even if you have a battery blanket. Once a lead-acid car battery has frozen, it will die very quickly from then on - I'd believe within a few days or less even in normal weather. AGM batteries are awesome alternatives for the cold weather lifestyle, in terms of their resistance to freezing damage.
Fradow 4y ago
That's because it is nonsense. I have a week-end only car (2002 Mini) and I've had no issue letting sit for a week or two. Including opening/closing it without starting the engine to retrieve stuff in that timeframe. And a week or two is on the low-end of how much you can let it sit. My SO car (1st gen citroen C3) often don't run for one or two month at a time and there is absolutely no issue with the battery. On the other hand, if you have parasitic drain and access to an electric socket, there are battery chargers that can keep the car topped up. Or without an electric socket, just unplug the battery when the car isn't used (though that may disable some things, for example in my car the hatch is inoperable without power).

by kccqzy 4y ago

stocknoob 4y ago

Or disconnect the battery (you’ll have to reset the clock, etc., which is annoying).

ChuckNorris89 4y ago
Not great advice. Most new-ish cars also store the dinamic engine calibration data in ECU RAM so if you disconnect the battery you can find your engine running harsher next time. So are the values of the headlights auto leveling system and other stuff. You're also risking to reset the radio/media unit security code (on cars that aren't too new but also not super old), which if you got the car second hand and the former owner didn't save the piece of paper it came with and give it to you, tough luck unlocking it.
- stocknoob 4y ago
  Not ideal to cut power to the entire car, but that happens anyway on every battery swap, no? If you want to get fancy you can isolate the exact fuse and switch just that: https://www.ebay.com/itm/175668177479 https://www.ebay.com/itm/175668177479 Thinking more, given how common parasitic drains are, carmakers should have all non-essential fuses in a separate subpanel section that can be easily switched off/diagnosed.
  - BenjiWiebe 4y ago
    No. Good automotive mechanics plug a little 12v power supply into the OBD port before replacing the battery, to keep the ECU/radio RAM powered.
- pvaldes 4y ago
  There are systems that can be attached to save the parameters from the car before you disconnect the battery or even to provide electricity to the car while the battery is being checked in another room. Not common to find and most people don't need them, but they exist.

peteradio 4y ago

It's nonsense! If a car is dying after not being driven for several months, ok fair enough. If after several days a particular year make model dies it deserves a recall!

maccard 4y ago

No car I've owned in the last decade has actually drained in a few days. Any car that does has a problem.

_ea1k 4y ago
I have this problem, but it really only becomes an issue when a few days becomes a few weeks. Do that a few times and the battery will lose capacity too.
- maccard 4y ago
  Weeks, sure. 2 weeks is probably on the lower end of acceptable though. My car is often left for 2 weeks and is completely fine, but most of the time it's weekly.

_ea1k 4y ago

Yes, they make battery tenders that are specifically for this. They'll trickle charge when needed, but also not charge at all when the battery is at the right voltage.

tadfisher 4y ago

You can drive a car from the 90s before they started shipping alarms and keyfobs in every vehicle. My 1995 Miata draws just enough power to maintain the clock in the radio, and it starts just fine after sitting for 6 months (it's not a winter car).

olyjohn 4y ago
My 2000 Ford Explorer has all kinds of electronics and modules from the factory. And even my crap I added in... I leave my Qi charger, ham radio, Bluetooth FM transmitter all running and plugged in, and I can come out a week later and the battery is still not dead. And when I'm camping I run a 12v van all night long. Truck starts right up every time. I don't get what would be draining more power than that in a more modern car. You'd think they'd be more efficient at not wasting juice.
- BenjiWiebe 4y ago
  A modern car is supposed to have single digit or less milliamp drain, according to a random car mechanic I know. I'm a mechanic but not automotive. That's after being off for 30 minutes though. Some things stay on for a while.

kybernetyk 4y ago

There's battery kill switches you can install onto the battery pole to effectively disconnect everything from the battery. This should work for older cars. For newer ones you may experience hiccups like reverse camera not working for a few hours until it has re-paired itself with the head unit.

SoftTalker 4y ago
Also the engine and transmission computers may go into "learn" mode if they are cold-starting having had no power for a while, and so you may have stuff like a wandering idle speed for a little while.
illumin8 4y ago
This really wouldn't work for any car made in the last 20 years. Most of them have anti-theft systems that require you to put in a PIN to use your stereo if it ever gets disconnected from the battery. I suppose you could type that in every single time, but there are other computers like your automatic transmission management that learn how you drive, etc, and might not like to get reset every day.
- windowsrookie 4y ago
  This is false. I have owned many different cars from the last 20 years and none of them did this when you disconnected the battery. A quick google search shows that it's Hondas that do this, not "any car made in the last 20 years".

tecleandor 4y ago

Really nonsense. It's true it might be more common due to all the additional modules and computers cars have now. If one goes crazy, it might drain your battery. But this is only in case of a failure. Edit: cold weather can accelerate that. If it's 'weekend only', battery should be no problem. If sometimes you leave it a couple months unused, that might be a problem. Depending on how ready you would like to be when you're going to use it, or the access you have to your car (is it far away or in your garage?) you could add a connector for a battery charger/maintainer (some of them have accessories for plugs you can leave permanently, see the NOCO GC002 for an example), and/or add a battery switch to easily disconnect the battery. Warning: your radio might ask for a security code if it loses battery connectivity. Be sure you have it.

red-iron-pine 4y ago
> Edit: cold weather can accelerate that. My Honda HRV dies anytime it gets below -7C. Outside, inside, driven a bunch a day or two before -- once it's cold that battery taps out. Probably a vampire drain but I suspect it's just a small battery. My old 2013 Mazda 3 starts in -25C without fail.
- Scoundreller 4y ago
  Could be a weak starter (and or the combination of that, a weak battery and maybe even bad ground straps).
ghaff 4y ago
I don't have extensive experience with my current car bought last summer but 2 weeks in warmer weather definitely wasn't an issue. I agree colder weather is always a bigger issue and at 1-2 months I'd definitely be thinking of a trickle charger if at all possible. An older car I didn't drive in the winter would definitely end up with a dead battery if I didn't keep it on a charger.
- EricE 4y ago
  AGM batteries are a lot more durable than regular lead-acid. They can cost a bit more but for me the longer life, more resistances to issues if you do run them all the way down and their sealed, maintenance free nature makes them the first thing I swap out. Optima used to be the only commonly available batteries but Costco, for example, has AGM equivalents for just about every battery out there - you may have to order it and wait a few weeks. They were also the original batteries used in Miata's since they give off a lot less hydrogen when charging. Since the Miata battery is in the trunk, and all lead acid batteries give off hydrogen when charging, and hydrogen in an enclosed space can also be rightfully called a bomb, having less of that is a good thing!

FartyMcFarter 4y ago

I didn't drive my 2019 Mercedes for months during the pandemic and the battery was fine. It did give me a warning when I restarted driving it (I guess the battery was starting to get low-ish), but it immediately fixed itself.

KMnO4 4y ago

You should see if there are carshare options around you. Even if you’re spending $50/weekend (which is a fair amount of driving — Communauto is as low as $3/hr), that’s still quite a bit cheaper than owning a depreciating asset with lifetime maintenance costs (not to even mention insurance and fuel).

ryukafalz 4y ago
Oh do I wish there were carshare options near me. Just moved from Philadelphia where ZipCar seems to be the only remaining contender, and you're lucky if there's one within a half hour's walk in the part of the city I was in. It's even worse in the town I moved to. There used to be a few at the nearby train station, but those seem to have disappeared. (This reminds me, I should go cancel my membership.) I'm jealous of the carshare options that seem to be available elsewhere. If it were as easy here as in this NJB video, it'd be a no-brainer: https://youtu.be/OObwqreAJ48 https://youtu.be/OObwqreAJ48
ambicapter 4y ago
"You will own nothing and you will be happy"
- tsgagnon 4y ago
  This must be the new astroturfing attack against concepts like public transportation. I've seen this phrase pop up too frequently at this point for it to be organic.
  - EricE 4y ago
    The simple may see it as astroturfing, others see it as an observation by those paying attention. I'm now living in a house I own without a mortgage because 20 years ago I bought a house and didn't rent. Utilities and property taxes are my only expenses. Yes, there is maintenance but if you don't think that's also factored into rent you are beyond delusional. Landlords aren't going to lose money out of the goodness of their hearts. I haven't had a car payment in over a decade because I take care of my stuff. The car goes in the garage; I don't fill my garage with a bunch of useless stuff I will likely never touch again (or pay someone else to store it!). Common sense stuff like the above, sadly, isn't common sense any more - so hence pithy phrases like own nothing and like it. A modern day emperor has no clothes, if you will.

heleninboodler 4y ago

Yeah, if a mechanic told me having the battery die in 3 days was normal, I'd stop going to that mechanic.

arscan 4y ago
I did that for the exact same problem on the same model car earlier this year, but gave up after trying a few places that all said the same thing (including the dealer). Glad to see this post though… now I know I’m not the crazy one.
- bityard 4y ago
  I would expect a _good_ car (no maintenance issues, new gas, newer battery) to go at least a couple months without being driven and not have any issues upon starting it up. The average car in average condition should go around a month without being driven. Anything less than that either means a battery nearing the end of its life, not getting charged, or a parasitic draw somewhere.
  - illumin8 4y ago
    We have a 10 year old Honda Odyssey that we keep just for long road trips and it has gone 3-4 months without being driven with no issues. I usually do try to fire it up every 1-2 months just to make sure the battery gets a charge and to avoid long term storage issues around oil and belts and other parts that degrade.
    - elzbardico 4y ago
      I would also make sure to use a fuel stabilizer like Pri-G, gasoline in a gas tank, depending on your climate can degrade pretty fast.
      - illumin8 4y ago
        Thanks, that's good advice. Luckily we've burned a tank or so every road trip (every few months) but I was wondering about that and whether it was good for gas to sit so long.

chrisdhal 4y ago

My wife drives about once a week, probably less on average. She has a 2013 Honda CR-V, only 15,000 miles on it. We live in Minnesota, so have cold temps, but the car in a garage. The car always starts. We've replaced the battery once just due to longevity. Every 3 days? No way.

yurishimo 4y ago
15k miles on a 2013 CR-V? Enjoy the last car you'll ever own! I assume you know this, but some of the maintenance items for that car are 8 years I think; worth checking the manual to find out!
- rconti 4y ago
  Tires should be first on the list!
- chrisdhal 4y ago
  Haha, yep. She refers to it as the literal "just driven to the grocery store by a little old lady" car (because it's basically that and Home Depot). She even got the lowest trim level (on purpose) so it doesn't have anything fancy (no BT radio, no keyless start, no big display, etc.). Good point on the maintenance. I do get the oil changed, again more by time than distance, and I'll look up the other stuff now that you've mentioned it, thanks.

rconti 4y ago

I try to keep my cars on trickle chargers (Noco Genius 5 in my case) when not driven regularly, because regularly killing $300 AGM batteries gets expensive. That said, I'd expect most cars should be able to manage, say, 2-3 months. It's when I exceed 4 months with some regularity that battery life starts getting sketchy. If you're driving the car every weekend, I'd expect that should be plenty. Note that fancier cars with more electronic features don't do well when only driven short distances. If you only drive 2-3 miles at a time, you might be discharging the battery faster than you're charging it.

aksss 4y ago

Table for reference: https://homebatterybank.com/how-fast-will-a-car-battery-drain/ https://homebatterybank.com/how-fast-will-a-car-battery-drai... That said, at between like 0F and -10F, I'd be intentional about starting that car every couple days. Below -10F to -20F, I'd start it each day. Below -20, I'd consider bringing the battery inside for the night - even if you have a battery blanket. Once a lead-acid car battery has frozen, it will die very quickly from then on - I'd believe within a few days or less even in normal weather. AGM batteries are awesome alternatives for the cold weather lifestyle, in terms of their resistance to freezing damage.

Fradow 4y ago

That's because it is nonsense. I have a week-end only car (2002 Mini) and I've had no issue letting sit for a week or two. Including opening/closing it without starting the engine to retrieve stuff in that timeframe. And a week or two is on the low-end of how much you can let it sit. My SO car (1st gen citroen C3) often don't run for one or two month at a time and there is absolutely no issue with the battery. On the other hand, if you have parasitic drain and access to an electric socket, there are battery chargers that can keep the car topped up. Or without an electric socket, just unplug the battery when the car isn't used (though that may disable some things, for example in my car the hatch is inoperable without power).