Iphone charges on a car battery

NormanPorkinson · 25 Mar 2011 at 22:20

Bit of a random question, but how many charges do you think a standard car battery can provide an iPhone with without it draining the car battery so that the car won't start?

I intend to use the cigarette lighter in-car charger to charge my iphone and I won't be turning the engine on as the car will be static. I go carp fishing and spend time (upto a week) on the bankside with no electricity, but with my car just behind me. I know that you could get a lot if the engine was running but obviously it won't be as I won't be going anywhere.

I have no knowledge about such things and was hoping that an engineer, car mechanic or other suitably qualified person could help.

thanks

Luke · 25 Mar 2011 at 22:22

I'd imagine weeks and weeks and weeks, but I'm sure someone will give you an answer based on real factors.

Werewolf · 25 Mar 2011 at 22:28

I think the answer would be a heck of a lot

However if you're going to be doing it a lot, the best way might be to get a cheap car or leisure battery and a simple car lighter style socket to hook up to it (I think electronics parts stores will sell something suitable*), that way you don't need to leave the key in the ignition (most cars seem to turn the lighter sockets off when the key is out), and zero worries about running the car's own battery down.
If you know anyone with a mobility scooter, they tend to need new batteries every couple of years, and the old ones would be fine for this sort of job

(not enough capacity to run the scooter, but loads for something like this).
You can then take the spare battery out of the car and charge it in your garage/house using a car charger when not in use

*I've got one in the garage somewhere that is intended to let me plug hook a small compressor up to a car battery if the car doesn't have a lighter socket (it's basically a lighter socket with a pair of crocodile clips and a fuse).

Impy77 · 25 Mar 2011 at 22:32

A week fishing? really?

NormanPorkinson · 25 Mar 2011 at 22:34

Impy77 said:
A week fishing? really?

Not normally, usually 24-48hrs, but I intend to do at least one 7 day session this year.

bobbydigital · 25 Mar 2011 at 22:45

Or you could get one of the portable jump start kits. Handy to have in the car and normally come with:

jump leads
air compressor
12v

NormanPorkinson · 25 Mar 2011 at 22:50

bobbydigital said:
Or you could get one of the portable jump start kits. Handy to have in the car and normally come with:

jump leads
air compressor
12v

Haha - This is what im trying to avoid but will bare it in mind

bobbydigital · 25 Mar 2011 at 22:54

Can pick them up cheap nowadays but who knows what the battery life is like on those models.

Bennie-Mac · 25 Mar 2011 at 23:01

A fully charged 200 amp-hour battery will, in theory, deliver 20 amps for 10 hours or 2 amps for 100 hours. The charger draws 0.3 amps, so the battery will run the charger for a maximum of 666 hours ((20/0.3) amps * 10 hours). Due to inefficiencies in batteries, the actual time will be about 2/3 of this: 444 hours.

This is all my own information and is in no way copied from ehow.com

Raymond Lin · 25 Mar 2011 at 23:03

Plus, you only need to charge it at most once a day anyway so 7 charges is nothing.

LOAM · 25 Mar 2011 at 23:49

Google solar ipod charger. Just leave it plugged in all day and leave your car battery alone

Edit, not sure you should bother, they look a bit carp.

NormanPorkinson · 26 Mar 2011 at 05:51

Bennie-Mac said:
A fully charged 200 amp-hour battery will, in theory, deliver 20 amps for 10 hours or 2 amps for 100 hours. The charger draws 0.3 amps, so the battery will run the charger for a maximum of 666 hours ((20/0.3) amps * 10 hours). Due to inefficiencies in batteries, the actual time will be about 2/3 of this: 444 hours.

This is all my own information and is in no way copied from ehow.com

This is what I was looking for. Thank you!

Thanks to everyone else too, most helpful