Flat battery -.-

[Total Drivin]

Saturday my daughter switched the interior light on in the car just after 12pm IIRC. With it being day time I didn't realise until about 11 at night when I went out to put the disklok on.

Didn't start the car until this morning and it only just had enough spunk to start it. I went about my business and returned home 15 minutes later.

My question is do I need to dig my charger out of the garage?

Battery is a Bosch and is less than 1 year old.

Car is a MK2 Focus ST.

Edited by Total Drivin on Monday 5th October 07:17

[eliot]

short answer is yes - takes hours to correctly charge a lead acid battery

[Miserablegit]

I’d put it on charge

If the battery was struggling to start I’m not sure a

15 min run will have put enough back in to charge up the battery. Batteries don’t like sitting at a low level of charge.

The fact a drain of about 15A ( 10 hours of interior lighting at about 1.5A as a wild guess) makes starting an issue suggests the battery was low anyway. Charge it and keep an eye on it

[Total Drivin]

Not the best charger as this is off my motorbike but should do the job.



How long should I leave it for?

[The Mad Monk]

Total Drivin said:

Not the best charger as this is off my motorbike but should do the job.



How long should I leave it for?

Why are you wearing those boots?

[Strudul]

Total Drivin said:

Not the best charger as this is off my motorbike but should do the job.



How long should I leave it for?

Until it's fully charged, as indicated by the battery icon on the right.

Bold choice of footwear, btw.

[Total Drivin]

It isn't my foot.

[Scrump]

That will switch into a maintenace mode when the battery is fully charged, so no need to worry about leaving it on too long. As said above the indicators will let you know when the battery charge is full.

[bluezedd]

Total Drivin said:

Not the best charger as this is off my motorbike but should do the job.

How long should I leave it for?

A quick google of "focus ST battery" gives results that are roughly 45Ah.

Think that charger is 3.8A.

So about 12 hours assuming those figures are right and the charger consistently provides 3.8A.

[E-bmw]

bluezedd said:

Total Drivin said:

Not the best charger as this is off my motorbike but should do the job.

How long should I leave it for?

assuming those figures are right and the charger consistently provides 3.8A.

As the battery charges it will slow the current rate at which it charges, so just do as others have said & leave it unti l the charger says it is fully charged.

[bluezedd]

E-bmw said:

As the battery charges it will slow the current rate at which it charges, so just do as others have said & leave it unti l the charger says it is fully charged.

Thats why I simplified it with the disclaimer of assuming a constant 3.8A. I was just giving OP an idea of how long it would take in case they were expecting it to be done in an hour or two.

[E-bmw]

bluezedd said:

E-bmw said:

As the battery charges it will slow the current rate at which it charges, so just do as others have said & leave it unti l the charger says it is fully charged.

Thats why I simplified it with the disclaimer of assuming a constant 3.8A. I was just giving OP an idea of how long it would take in case they were expecting it to be done in an hour or two.

I got that & I was just elaborating further.