6 ms·

If the battery is flat on the car then you are still pretty much out of luck even if you can get in. The only advantage to being able to open it is to use it as

If the battery is flat on the car then you are still pretty much out of luck even if you can get in. The only advantage to being able to open it is to use it as shelter in a emergency situation

ebg13 7y ago
> If the battery is flat on the car then you are still pretty much out of luck even if you can get in. With an EV yes, but not with an ICE. Just keep a jump box in your trunk.
- williamstein 7y ago
  These "jump boxes" are amazing! I used to keep big jumper cables and have AAA in case of a dead battery. Last time AAA came (after I waited hours...), they just pulled out a little "jump box" and instantly started my car. I found and bought a random one on Amazon (there are dozens -- https://www.amazon.com/s?k=car+jumpstart https://www.amazon.com/s?k=car+jumpstart). It's very small, can also be used to charge a cell phone, as a flashlight, etc., and really works. Every ICE should have one of these in the trunk.
  - pdkl95 7y ago
    Note that the battery in a "jump box" is probably capable of discharging a dangerous amounts of energy at very high current. BigClive measured[1] over >500A when he tried to discharge one of these batteries, which didn't actually work. The internal Li plates probably separated, breaking the circuit before fully discharging. After starting to disassemble the battery and realizing the that the plates had separated he attached a voltmeter and measured a full 3.6V across the supposedly-discharged, partially disassembled battery (squeezing the battery with his hands, "This still is fully charged, but it's just puffed up... that's a bit scary." Later, after the Li plates start changing color (!) - probably metallic Li starting to rapidly oxidize - they spontaneously ignited (pyrophoric). The benefits of having a spare "jump box" in the trunk are obvious, but it's important to remember that this means carrying a dangerous amount of energy in form that is a very serious fire risk if anything damaged the battery. [1] https://www.youtube.com/watch?v=0tGK1nqXr28 https://www.youtube.com/watch?v=0tGK1nqXr28
infectoid 7y ago
And having shelter from the rain while you wait for someone to arrive can be a great advantage. I'm sure there are many other fantastic reasons to want access to your vehicle when the battery is flat.
- Bartweiss 7y ago
  Yep, that's potentially a huge difference. If you can't open the car, you probably can't pop the hood latch to get a jump-start, which makes the difference between a tow and a simple drive to a store. And "stuck alone at the trailhead with a dead battery" is nothing new to hikers, but being able to spend the night in the car if you have to makes it a lot more pleasant.
mirimir 7y ago
That depends on the vehicle. If it's an ICE with a manual transmission, and you can get it moving fast enough, you can pop the clutch to start it. Back in the day, with a ~dead battery, I'd park on a hill. Even without a hill, 2-3 people can generally just push.
- mwilliaams 7y ago
  And what percentage are manual transmission vehicles these days? Probably less than 1
  - nraynaud 7y ago
    90% of southern Europe?
    - rocqua 7y ago
      Why just southern Europe? Here in West Europe there is still a vast majority of manual transmission.
  - mirimir 7y ago
    True. But some of us still like them. I'm not hard core enough to have a pre-computer vehicle, though.
  - macintux 7y ago
    Some models it’s much higher, but overall definitely single digits in the U.S. Europe has a much higher take rate on manuals.
  - dividedbyzero 7y ago
    >>90% in Germany
- wolrah 7y ago
  > That depends on the vehicle. If it's an ICE with a manual transmission, and you can get it moving fast enough, you can pop the clutch to start it. This depends on just how dead it is on newer cars. If it's able to run the electronics but just unable to crank enough to start, this can work. If it's dead enough that you can't unlock the doors it's probably also dead enough that the fuel pump, ECU, etc. aren't going to be able to do their thing. Carbureted vehicles can be bump started from flat dead for the most part, but EFI and especially direct injected vehicles need some electricity to operate.
silon42 7y ago
Last year, we push-started my dads car where battery was so bad it could not be charged or jump started from another car. Push start worked the first time (car from 2009).

If the battery is flat on the car then you are still pretty much out of luck even if you can get in. The only advantage to being able to open it is to use it as shelter in a emergency situation

ebg13 7y ago

> If the battery is flat on the car then you are still pretty much out of luck even if you can get in. With an EV yes, but not with an ICE. Just keep a jump box in your trunk.

williamstein 7y ago
These "jump boxes" are amazing! I used to keep big jumper cables and have AAA in case of a dead battery. Last time AAA came (after I waited hours...), they just pulled out a little "jump box" and instantly started my car. I found and bought a random one on Amazon (there are dozens -- https://www.amazon.com/s?k=car+jumpstart https://www.amazon.com/s?k=car+jumpstart). It's very small, can also be used to charge a cell phone, as a flashlight, etc., and really works. Every ICE should have one of these in the trunk.
- pdkl95 7y ago
  Note that the battery in a "jump box" is probably capable of discharging a dangerous amounts of energy at very high current. BigClive measured[1] over >500A when he tried to discharge one of these batteries, which didn't actually work. The internal Li plates probably separated, breaking the circuit before fully discharging. After starting to disassemble the battery and realizing the that the plates had separated he attached a voltmeter and measured a full 3.6V across the supposedly-discharged, partially disassembled battery (squeezing the battery with his hands, "This still is fully charged, but it's just puffed up... that's a bit scary." Later, after the Li plates start changing color (!) - probably metallic Li starting to rapidly oxidize - they spontaneously ignited (pyrophoric). The benefits of having a spare "jump box" in the trunk are obvious, but it's important to remember that this means carrying a dangerous amount of energy in form that is a very serious fire risk if anything damaged the battery. [1] https://www.youtube.com/watch?v=0tGK1nqXr28 https://www.youtube.com/watch?v=0tGK1nqXr28

infectoid 7y ago

And having shelter from the rain while you wait for someone to arrive can be a great advantage. I'm sure there are many other fantastic reasons to want access to your vehicle when the battery is flat.

Bartweiss 7y ago
Yep, that's potentially a huge difference. If you can't open the car, you probably can't pop the hood latch to get a jump-start, which makes the difference between a tow and a simple drive to a store. And "stuck alone at the trailhead with a dead battery" is nothing new to hikers, but being able to spend the night in the car if you have to makes it a lot more pleasant.

mirimir 7y ago

That depends on the vehicle. If it's an ICE with a manual transmission, and you can get it moving fast enough, you can pop the clutch to start it. Back in the day, with a ~dead battery, I'd park on a hill. Even without a hill, 2-3 people can generally just push.

mwilliaams 7y ago
And what percentage are manual transmission vehicles these days? Probably less than 1
- nraynaud 7y ago
  90% of southern Europe?
  - rocqua 7y ago
    Why just southern Europe? Here in West Europe there is still a vast majority of manual transmission.
- mirimir 7y ago
  True. But some of us still like them. I'm not hard core enough to have a pre-computer vehicle, though.
- macintux 7y ago
  Some models it’s much higher, but overall definitely single digits in the U.S. Europe has a much higher take rate on manuals.
- dividedbyzero 7y ago
  >>90% in Germany
wolrah 7y ago
> That depends on the vehicle. If it's an ICE with a manual transmission, and you can get it moving fast enough, you can pop the clutch to start it. This depends on just how dead it is on newer cars. If it's able to run the electronics but just unable to crank enough to start, this can work. If it's dead enough that you can't unlock the doors it's probably also dead enough that the fuel pump, ECU, etc. aren't going to be able to do their thing. Carbureted vehicles can be bump started from flat dead for the most part, but EFI and especially direct injected vehicles need some electricity to operate.

silon42 7y ago

Last year, we push-started my dads car where battery was so bad it could not be charged or jump started from another car. Push start worked the first time (car from 2009).