Flat battery

[RDH]

After leaving the headlights on last night my battery unsurprisingly was completely flat!

How long does a battery take to recharge?
I.e. how far will i need to drive for it to retain enough charge, to leave it parked up overnight and expect it to restart?

[meatball]

30min of slow driving with everything off?

[mac]

I've got a multi-meter at home, swing past on your way home and we can see what kind of voltage is in there just now.


I've also got a charge set up - so if it is looking low we can stick the battery on charge and I'll run you home and either cadge a lift over later on or first thing tomorrow morning on you way to work

[RDH]

I've got a multi-meter at home, swing past on your way home and we can see what kind of voltage is in there just now.


I've also got a charge set up - so if it is looking low we can stick the battery on charge and I'll run you home and either cadge a lift over later on or first thing tomorrow morning on you way to work

Cheers Mac!
I'll try running it to the hospital for visiting in Kilmarnock straight after work - 40 mins/30 miles should do it - failing that I may give you a call tomorrow.

[mac]

That should be fine - I was working on you just doing the commute


Won't be around tomorrow night - being sophisticated

[thinfourth]

how long is a piece of string question

Could be 5 minutes with a small healthy battery and a good alternator

Could be an hour with huge battery and iffy alternator

[RDH]

how long is a piece of string question

Could be 5 minutes with a small healthy battery and a good alternator

Could be an hour with huge battery and iffy alternator

Point taken - I'll try an hour, alternator is fine ( touch wood) 10 minutes to work this morning wasn't enough!

[meatball]

I'm lotus-less and have all day free......if you are stuck????

[robin]

Where possible use the alternator to charge the battery not a battery charger (the alt produces way more current than typical chargers and there is no danger of frying anything using the alternator).

Say 75A charge rate, <200Ah battery, might take a couple of hours to completely charge the battery from flat, but 20-30 minutes should easily be enough to get back to the point of being able to start the car.

Bigger problem is that the battery is probably half gubbed - they don't like being deep discharged.

Cheers,
Robin

[RDH]

Where possible use the alternator to charge the battery not a battery charger (the alt produces way more current than typical chargers and there is no danger of frying anything using the alternator).

Say 75A charge rate, <200Ah battery, might take a couple of hours to completely charge the battery from flat, but 20-30 minutes should easily be enough to get back to the point of being able to start the car.

Bigger problem is that the battery is probably half gubbed - they don't like being deep discharged.

Cheers,
Robin

Came to the conclusion that after 2 x hour long runs following jump starts and it failing to restart that the battery is gubbed!

New battery - all working!

[espritstu]

take the battery out,whilst under charge it will be reading over 14 volts with a meter,once charged it will read approx 12.8 volts,let the batttery sit a while and if the reading stays the same its ok,if the reading has dropped e.g 10.9 volts etc batt is finished