Ran My Car's Battery Flat With The Dome Light On

[Brettster]

I left the front dome light on by accident for an hour, doh!! and now my car will not start. I can hear the starter clicking. can I bump start an auto? or is this a very bad thing?

I also think my Battery has had its day, so im going to get a better one tomorrow.

[ricky_is200]

Bad thing to do with a catalitic converter, unburnt fuel can get into it or something. Can you get a jump start from someone? Or call out the RAC?

[BESTY]

i agree i would get a start off someones car with leads :)

[Matthew_McNally]

Bad thing to do with a catalitic converter, unburnt fuel can get into it or something. Can you get a jump start from someone? Or call out the RAC?

thought a jump start was a bad idea ricky?

could fry some electronic compenents (ecu??)

thought the right answer was a slowish recharge?

[Rob]

cant bump start an auto, but you can just jump start it - if your Battery was dead after an hour with only the dome light on then the Battery is shafted, get a new one. Also have a look to see if you can get one with a bigger capacity as the standard Battery is only 45A.

If you do it yourself dont worry about radio codes etc - the IS doesnt have any, you will only loose your radio settings and have to reset the clock - you might also hear a slight beeping noise when you disconnect the battery- dont worry this is the alarm unit beeping ( not the siren) and it will stop after about 5 secs.

[BESTY]

what is the best Battery for the IS 200

[Scorpion]

I've left mine on all night before and not had a problem starting,so i guess

your Battery is knackered.

[Rob]

what is the best battery for the IS 200

as long as u get a Battery that has roughly the same "footprint" size then it doesnt really matter - some people have gel batteries but i think because they also have quite a lot of ICE equipment also so quite a high drain. ( do u have lots of extras on ur car?)

im changing mine next month and have found one that has the same footprint and is a little taller but its 60A - suits me fine, cant give u the name as its from the supermarket and only €50.

[Brettster]

thanks guys. how long are batteries supposed to last for? the cars 4 years old now and i assume its still the original one in the car

[Monster-Mat]

normally 3 years

[Brettster]

i have a few extras in the car

the stereo is standard I have illuminated scuffs and a pc in the glovebox but the pc only powers up after the car has started. I looked into a Gel Battery but I didnt fancy paying over £200 plus.

I have noticed that my car has been taking a good 5 - 7 turns to start when cold. it had its 60k service last month and the plugs changed so im hoping a new Battery will sort that out too

[Chris.S]

I completely drained my Battery the othe week by leaving the boot open,

didn't realise until 4 days later.

Came to it and it had no power what so ever, not even dash warning lights. borrowed a Battery booster pack and got it going that way.

[Monster-Mat]

but your Battery is brand new chris almost :D

[Chris.S]

but your battery is brand new chris almost :D

Yeah but I left the boot open, with the boot light on for 4 days and didn't know until I came to get the car out of the garage to take it to work to have the wheels replaced

[Rob]

you will notice it a lot at the mo if ur Battery is on its way out -as soon as it gets cold it will take a lot longer to start the car. I wouldnt bother with a gel Battery, just try and get a higher capacity Battery.

as u say it takes 5-7 turns to start then its defo knackered - easiest way to check if ur Battery is going south is to connect a voltmeter up to it, put it so you can see it from inside the car - ie on the windshield, start the car then turn it off, it will drop to about 10/9 volts then go back up, do this about 3 times, the Battery should recover fairly quickly back to 12 volts and should stay about the same level when starting the car ie about 9/10 ish volts, if it keeps dropping then you need a new Battery. mine drops to abot 9 volts then takes ages to get back to 12 volts, mine is also 4 years old.

[GreyBeard]

thanks guys. how long are batteries supposed to last for? the cars 4 years old now and i assume its still the original one in the car

i've got one in a renault van that's been there 6.5 years and has once been filled up with 1.5L of tap water, and it's still going fine! surprised that the 'reliable' lexus ones don't last longer.

[Brettster]

while i was installing the PC I noticed the voltage's and while cranking the car it drops to around 6 volts. while running its around 12.5 - 13.5 volts and with the engine off its around 11.8 volts. my voltage regulator for the PC requires 13.5 input to give out a regulated 12V so do you think a better Battery would also sort out this little problem.

while i had the engine running and the pc running everything worked fine until I switched something on like the heated seats or even just using the breaks would drop the voltage and reset the pc. maybe im asking too much from a 45amp Battery?

[Monster-Mat]

this is the offset of a maint free Battery......

as its maint free, its a disposable item, with the one in your Renault, its able to top it up, therefore it will last longer, plus modern cars use much more electrical components, all this adds to a less longer lasting Battery.

there are talks in the automotive world of eventually moving over to 48v batteries

[Brettster]

this is the offset of a maint free battery......

as its maint free, its a disposable item, with the one in your Renault, its able to top it up, therefore it will last longer, plus modern cars use much more electrical components, all this adds to a less longer lasting battery.

there are talks in the automotive world of eventually moving over to 48v batteries

will a higher voltage Battery solve anything? I would have thought a higher ampage would be more usefull??

[ColinBarber]

If you have a higher voltage then the current required is reduced, more efficent.

The Toyota hybrid system uses batteries that provide 200volts to the motors.

[Guest mark_tsang]

you will notice it a lot at the mo if ur battery is on its way out -as soon as it gets cold it will take a lot longer to start the car. I wouldnt bother with a gel battery, just try and get a higher capacity battery.

as u say it takes 5-7 turns to start then its defo knackered - easiest way to check if ur battery is going south is to connect a voltmeter up to it, put it so you can see it from inside the car - ie on the windshield, start the car then turn it off, it will drop to about 10/9 volts then go back up, do this about 3 times, the battery should recover fairly quickly back to 12 volts and should stay about the same level when starting the car ie about 9/10 ish volts, if it keeps dropping then you need a new battery.  mine drops to abot 9 volts then takes ages to get back to 12 volts, mine is also 4 years old.

i notice it takes longer to start up & almost couldnt start it up, took about 4/5 times but got worse yesterday, mine is still original Battery, 1999 altezza, i got it recharged today so is improved for now till i buy new one which i hope is the Battery rather than anything other fault

i thought it was somethine else wrong like spark plugs - my mates car couldnt start up last wk, thought it was the Battery (still original one) but turned out to be dirty spark plugs.

[ricky_is200]

thought a jump start was a bad idea ricky?

could fry some electronic compenents (ecu??)

That's what Lexus assistance did when I ran my Battery down, they just jump started it and it was fine.