How long for battery to drain?

[WD Pro]

I’ve had batteries covered under BMW’s extended warranty so it’s defo worth an ask

WD

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[hinch]

I’ve had batteries covered under BMW’s extended warranty so it’s defo worth an ask

WD

this is ford i'd be surprised if their extended warranty actually covered a car and not just "function of manual key"

 

[wenklaw]

I constantly had to trickle charge my M2 due to error messages, BMW didn’t want to know! Never had it fail to start but when I used the trickle charger the message went away.
I would expect to be able to leave a car for 4 months let alone 4 weeks without battery issues unless the battery is banjaxed.
I’m using my GT about once every 10 days for a 10-12 mile round trip, last time I started it I did receive some sort of battery saving message, so the trickle will be going on. Still started fine though as expected

 

[CaptainSensible]

Worth investing in a trickle charger to preserve the life of your battery. Costs less than a tank of fuel. I've got one on mine and even though I've only driven it twice since start of March it still starts on the button.

 

[Dannyh1991]

Also getting this message now when I get into car, have drove it around for a good 40mins or so but its still there, not struggling to start or anything but will stick a battery tester on it today or tomorrow.

 

[hinch]

leave it for a couple of days and it'll struggle to start too this is what mine was doing its on the verge of death. i'm hoping a proper charger will fix mine if not i guess the batter is fubar

 

[Dannyh1991]

leave it for a couple of days and it'll struggle to start too this is what mine was doing its on the verge of death. i'm hoping a proper charger will fix mine if not i guess the batter is fubar

Yeah, hooked up a battery tester today and before I started the car it was at 50% and at the rate it was accepting charge it would have took 2 hours to be fully charged. I'll need a new battery soon, not too expensive for these cars by the looks of it. Even if it lasts, I Will definately need one before winter.

 

[FAB Cruiser]

Quick follow up...

If I press the start button without starting the engine (e.g. for an auto, without depressing the brake) the red battery light comes on. Will this always happen, even with a new battery or is it meant to indicate a low charge?

I ask because on other cars with keys, several warning lights come on when you turn the key to the ignition position and extinguish when the engine fires to prove the individual bulbs are working.

Of course, once the engine is running, the alternator kicks in and the light goes out.

cheers
David

 

[SurfOrFight]

Almost all modern cars drain down a battery when not in use. I charge the mustang every 2 weeks, when not in use, using a trickle charger. This is a minimum in requirement in cold weather, in my mind. My wife's Kuga failed to start last week after laying up for 3 weeks. Just charge back up for a few hours every couple of weeks, it's not rocket surgery!

 

[WD Pro]

A lead acid battery will drain even when it’s not in use and disconnected from any equipment. OK, it will take a lot longer than if it’s got a small load on it (e.g. security system) but it’s still a consideration, especially if you plan on storing one.

Self discharge rate will vary depending on technology / plate purity / storage conditions and it’s rare you will get anything more than a generic recommendation / guidelines from the manufacturer.

Bottom line - check and maintain any lead acid battery regardless of its make, technology or application

WD

 

[inky5.0]

Quick follow up...

If I press the start button without starting the engine (e.g. for an auto, without depressing the brake) the red battery light comes on. Will this always happen, even with a new battery or is it meant to indicate a low charge?

I ask because on other cars with keys, several warning lights come on when you turn the key to the ignition position and extinguish when the engine fires to prove the individual bulbs are working.

Of course, once the engine is running, the alternator kicks in and the light goes out.

cheers
David

Not too sure - I’m sure the handbook will say - but my theory with warning lights is that they are only an issue after the car is started and running...

 

[Rapid Red]

Lets say its a 200 amp battery , @ 1 amp draw 200 hours

 

[Rapid Red]

Also getting this message now when I get into car, have drove it around for a good 40mins or so but its still there, not struggling to start or anything but will stick a battery tester on it today or tomorrow.

First question, how old is the battery? Second question has it been replace ? Third question what is the battery manufacture and grade ?

 

[WD Pro]

Lets say its a 200 amp battery , @ 1 amp draw 200 hours

To 100% DOD, it will be well before then when it reaches the point where it fails to start ...

WD

 

[Rapid Red]

To 100% DOD, it will be well before then when it reaches the point where it fails to start ...

WD

A big no kidding, answering the question
How long for battery to drain

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