Left the Lights On!
Discussion
Yep...numb nuts here left the lights on, on the Griff all night. Not the best start to the week.
The battery is so flat that it wouldn't even open the doors, so the question is what is the best way to re-charge the battery in a limited amount of time?
Ideally I need the car up and running again for tomorrows commute, so I'm planning on a jump start when I get home tonight followed by a bit of hoon about, but I'd be interested to hear peoples thoughts.
Am I likely to damage the battery with this method? Would I be better off buying a charger and charging over night?
Can I exepect any further problems as result of a fully drained battery?
All advice greatfully received..
thanks, Matt.
The battery is so flat that it wouldn't even open the doors, so the question is what is the best way to re-charge the battery in a limited amount of time?
Ideally I need the car up and running again for tomorrows commute, so I'm planning on a jump start when I get home tonight followed by a bit of hoon about, but I'd be interested to hear peoples thoughts.
Am I likely to damage the battery with this method? Would I be better off buying a charger and charging over night?
Can I exepect any further problems as result of a fully drained battery?
All advice greatfully received..
thanks, Matt.
catretriever said:
I'd be interested to hear peoples thoughts.
Mine was dead to at the weekend, jump stared it no problems, did a 40 mile blat to Fernies to take it for its month holiday. Getting a few things done and now getting a ciggy charger installed as well. OH
Not sure why mine went flat after a week, it's not the first time its been left alone! she's probably just sulking!
If your battery is very flat driving around for a bit may not charge your battery enough to start it.
Depending just how flat it was you could have problems charging it with a normal battery charger, when mine was very flat the charger would just show an error message
most places would then quite happily sell you a new battery but by connecting the battery via some jump leads to another battery (I used a battery booster) for a few hours, to drip a bit of charge into it, then connecting the battery charger over night, and my battery has been fine for the last 10 months 
I do now use an Accumate though
Depending just how flat it was you could have problems charging it with a normal battery charger, when mine was very flat the charger would just show an error message
most places would then quite happily sell you a new battery but by connecting the battery via some jump leads to another battery (I used a battery booster) for a few hours, to drip a bit of charge into it, then connecting the battery charger over night, and my battery has been fine for the last 10 months I do now use an Accumate though
Must be the time for batteries to think about hibernation! Two of our cars batteries went flat overnight on Saturday for no apparent reason.
First the TVR, well OK it hasn't had much exercise recently but over the past 2 years I've left it for weeks at a time without problems and I used it on Saturday. But Sunday morning there was just enough juice to open the doors.
So I went to my daughter's Rover 25 to jump start the TVR and this was flat as a pancake! At this stage I was running out of cars. So I jump started the Rover off the wife's Focus and did a 35 mile round trip in the Rover to Halfords to buy a charger.
Put the TVR on charge for 3 hours and it turned the engine over like a goodun the next morning.
But the Rover was flat again the next morning.
The morale of the story? It seems a 35 mile drive with two starts isn't enough to charge a battery but a full cycle on a charger is.
BTW I bought the ABSAAR 12V 20 amp with 180amp starter boost, rather than Halford own. At £53 it was £20 more than the Halfords own-brand but the starterboost with allow you to start the car on the boost within a minute or two providing the battery wasn't fully discharged. I think this is a useful facility since flat batteries usually occur when you need to use the car and to get going within a minute or so is a real help.
First the TVR, well OK it hasn't had much exercise recently but over the past 2 years I've left it for weeks at a time without problems and I used it on Saturday. But Sunday morning there was just enough juice to open the doors.
So I went to my daughter's Rover 25 to jump start the TVR and this was flat as a pancake! At this stage I was running out of cars. So I jump started the Rover off the wife's Focus and did a 35 mile round trip in the Rover to Halfords to buy a charger.
Put the TVR on charge for 3 hours and it turned the engine over like a goodun the next morning.
But the Rover was flat again the next morning.
The morale of the story? It seems a 35 mile drive with two starts isn't enough to charge a battery but a full cycle on a charger is.
BTW I bought the ABSAAR 12V 20 amp with 180amp starter boost, rather than Halford own. At £53 it was £20 more than the Halfords own-brand but the starterboost with allow you to start the car on the boost within a minute or two providing the battery wasn't fully discharged. I think this is a useful facility since flat batteries usually occur when you need to use the car and to get going within a minute or so is a real help.
!! Very important !! don’t start the car using a booster and don’t charge a flat battery whilst still attached to the car with anything other than a very good quality power supply.
Battery chargers and in particular high power ones ( boosters) produce a very rough output. Rather than clean constant DC you get pulses of DC with enormous high voltage spikes often in excess of several hundred volts. The spikes are no problem to the battery and in fact are quite god at braking down the sulphate. What they will do however is have a good try at destroying your ECU, Alarm and Immobiliser.
If you let a modern battery go flat and leave it flat for more than a few days a layer of sulphate will accumulate on the plates. This then effectively insulates the plates from the acid and can dramatically reduce the capacity. If for example half of the surface area is sulphated then you will have half the capacity of before. Several charge discharge cycles may regain some of the capacity but you are unlikely to get it all back.
To specifically answer the question, the best way of quickly charging the battery is from the alternator, if the car still won’t start after 30 miles chances are the battery is scrap.
Battery chargers and in particular high power ones ( boosters) produce a very rough output. Rather than clean constant DC you get pulses of DC with enormous high voltage spikes often in excess of several hundred volts. The spikes are no problem to the battery and in fact are quite god at braking down the sulphate. What they will do however is have a good try at destroying your ECU, Alarm and Immobiliser.
If you let a modern battery go flat and leave it flat for more than a few days a layer of sulphate will accumulate on the plates. This then effectively insulates the plates from the acid and can dramatically reduce the capacity. If for example half of the surface area is sulphated then you will have half the capacity of before. Several charge discharge cycles may regain some of the capacity but you are unlikely to get it all back.
To specifically answer the question, the best way of quickly charging the battery is from the alternator, if the car still won’t start after 30 miles chances are the battery is scrap.
raceboy said:
If your battery is very flat driving around for a bit may not charge your battery enough to start it.
Depending just how flat it was you could have problems charging it with a normal battery charger, when mine was very flat the charger would just show an error message
I do now use an Accumate though
Yup, that's what I do. Put a little bit in from a parallel battery and then charge it overnight. Seems to be the kindest way once you have completely flattened the battery. I also have hop-points in the footwell and a cut off switch down there to make it all a lot easier.
steve-v8s said:
!! Very important !! don’t start the car using a booster and don’t charge a flat battery whilst still attached to the car with anything other than a very good quality power supply.
Would you class a jump from another vehicle as a good quality supply?
I'm assuming that my battery is completely drained since the remote locking won't even work.
Is the only viable route a slow charge overnight
Jump from another car is fine, try to ensure that the leads make a good connection as it is not helpful if they arc. You will need a good set of leads, most high street ones are so cheap and nasty when you try to draw a couple of hundred amps it all turns into heat. If you only have cheap jump leads then as was suggested, leave the cars connected for an hour or so and let some charge accumulate in the flat battery.
[quote=steve-v8sIf you let a modern battery go flat and leave it flat for more than a few days a layer of sulphate will accumulate on the plates. This then effectively insulates the plates from the acid and can dramatically reduce the capacity. If for example half of the surface area is sulphated then you will have half the capacity of before. Several charge discharge cycles may regain some of the capacity but you are unlikely to get it all back.[/quote]
Seconded. The one time I let my relatively new battery go flat, it recovered only to let me down a few weeks later. Deep discharging a battery on a TVR can require a new battery.
Ian A.
Seconded. The one time I let my relatively new battery go flat, it recovered only to let me down a few weeks later. Deep discharging a battery on a TVR can require a new battery.
Ian A.
Well, I shelled out on one of those rechargable battery pack jump start thingies & it worked like a dream. Followed by a 25mile dusk hoon around the Hertfordshire countryside. The car started just fine this morning and seems to be happy and healthy again.
I'll let you know if I have any more problems, and I'll be carrying my groovy jumpstart gizmo around with me from now on!
thanks again!
I'll let you know if I have any more problems, and I'll be carrying my groovy jumpstart gizmo around with me from now on!
thanks again!
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