Came Back From My Holiday Today

[Messiah]

It may take several days of everyday driving for the battery to fully recover. My 32 often fails to have enough grunt to start because I might not drive it for more than a week, but then after a couple of days of everyday use, the battery is fine again. And the battery is a couple of years old now.

CARSICK - it doesn't really matter how many volts are available BEFORE startup - and 14V is too many, should only be about 12V - what is important is how many volts and amps are available DURING startup.

A little wrong on that last bit, Voltage does matter, keep in mind theres is a relationship between Volts, Amps and Watts. A deficiency in one will mean the others need adjustment to maintain the same result. So yes, amperage is watt (hah i made a funny) matters, but the others come into play in making that amperage possible.

From experience i can tell you that 14v is not too much. I kept my car in storage for quite some time, and would regularly have issues starting it up if i left it too long.

Being left it wouldnt always catch first go, and if repeat goes dropped the voltage below 12.5 minimum, it wouldnt start up no matter what i did. Leave it 15 mins and try again. No problems.

[DC33VN]

im pretty much forced to buy a new battery because my mums bf is a moron because he thinks ill stuff up the aurions ecu or something. I had jump started the car at my uncles where i left the car and drove it back here which was a big mistake because my mums bf is a real idiot

[mad082]

It may take several days of everyday driving for the battery to fully recover. My 32 often fails to have enough grunt to start because I might not drive it for more than a week, but then after a couple of days of everyday use, the battery is fine again. And the battery is a couple of years old now.

CARSICK - it doesn't really matter how many volts are available BEFORE startup - and 14V is too many, should only be about 12V - what is important is how many volts and amps are available DURING startup.

if your battery is dying from not being driven for a week then your battery is stuffed. when my mother had an operation on her hand her car went 4 weeks without being driven and started fine. the longest i've had a car sit without being started (and with the battery still connected) was 2 months, and it still started fine.

my family is really stupid when it comes to cars i asked my mum 2 let me jump start my car and my step dad goes no it cant stuff the cars ecu by doing it because it happened to his old patrol and i just didnt even bother arguing with him...

yeah they sound like the typical uneducated (mechanically uneducated) people that have heard from someone who had a mate, who had a mate who heard from a mate that a mate of theirs had their ecu blow when they jumpstarted the car. what they don't realise is that for the ECU to blow you'd have to have a faulty fuse somewhere along the line. i've jumpstarted fuel injected cars dozens of times and never had an issue. i use the following method:

hook up the earth on the running car's battery

hook up the earth on the flat battery

hook up the + on the running car

hook up the + on the flat battery

and then when i'm done i take it off in the reverse order.

[**RB2530**]

I 'think' it may be a case of early ECUs being quite sensitive to spikes and transients that may occur during a jump start...Now they are a very refined bit of kit and their sensitivity has been designed out..

So thats how this story may have started...

[DC33VN]

loll thats exactly right mad082 it happened to my mums bf's 4wd when he jump started it something along those lines. its funny because he was talking to me awhile back about a racing car his dad had and that he worked on yet he doesnt know anything about jump starting a car.... thats typical wog parents for you lol

[mad082]

i think a lot of people also do it wrong, or disconnect both clamps from the 1 battery at a time and after they take the first one off they hold them together in the 1 hand and they touch and arc out and possibly melt some wiring.

[blind_elk]

A little wrong on that last bit, Voltage does matter, keep in mind theres is a relationship between Volts, Amps and Watts. A deficiency in one will mean the others need adjustment to maintain the same result. So yes, amperage is watt (hah i made a funny) matters, but the others come into play in making that amperage possible.

Did you READ what I wrote? I said that static voltage before starting is irrelevant, and that available voltage during the start procedure is what counts. Many batteries will show a "full" charge, but cannot start the engine.

From experience i can tell you that 14v is not too much.

A static battery should not have more than 12 and a bit volts. A running engine will show around 14V at the battery because that is what the alternator's regulator is controlling it to. And the reason the voltage is around 14V is so that the chemical reaction that produces the static voltage in the first place actually "runs" in reverse.

mad082, the battery is supporting an alarm, a radio with battery backup, and a clock with battery backup. All these act to drain the available voltage from the battery. (And the battery is a few years old now, admittedly)

Apparently the secret to not blowing things up is to switch the parking lights on before disconnecting jump leads. That way, some of the excess current being generated by the alternator has somewhere to go, other than to the jumping battery, which suddenly "disappears" from the circuit.

[mad082]

Did you READ what I wrote? I said that static voltage before starting is irrelevant, and that available voltage during the start procedure is what counts. Many batteries will show a "full" charge, but cannot start the engine.

A static battery should not have more than 12 and a bit volts. A running engine will show around 14V at the battery because that is what the alternator's regulator is controlling it to. And the reason the voltage is around 14V is so that the chemical reaction that produces the static voltage in the first place actually "runs" in reverse.

mad082, the battery is supporting an alarm, a radio with battery backup, and a clock with battery backup. All these act to drain the available voltage from the battery. (And the battery is a few years old now, admittedly)

Apparently the secret to not blowing things up is to switch the parking lights on before disconnecting jump leads. That way, some of the excess current being generated by the alternator has somewhere to go, other than to the jumping battery, which suddenly "disappears" from the circuit.

still, if the battery is draining by that much in a week then it is time for a new battery. my 33 used to only get driven occasionally and it had all the same setup and it would still easily start after a week or 2. and i had an n14 pulsar with an alarm, stereo, clock, etc and it sat for a few weeks between being driven, and then when it was driven it was only probably only for about 10 mins to the shop and back.

[Messiah]

Did you READ what I wrote? I said that static voltage before starting is irrelevant, and that available voltage during the start procedure is what counts. Many batteries will show a "full" charge, but cannot start the engine.

yeah i READ what you wrote, and you wrote an incredibly cut down version of the details, as did i? simple fact of the matter is we're agreeing the principle and knattering over the details, i will admit tho i missed your mention of voltage and only noticed wattage. but chill, i wasnt calling you a dumb ass just correcting a point of yours i though warrented a little more info.

but you are correct, 14v is what is displayed when running, but i'm pretty certain my car wouldnt kick over if it read less than 12.5. Also if i cranked it a few times and it dipped below, it wouldnt start until i left it a little while and the voltage crept up again.

But at the end of the day it seems we agree. Not enough voltage/wattage before cranking will certainly mean not enough during. And with a flattish battery that is what you'll get, shows enough juice to turn on a light or an alarm, but will lack the staying power the crank it over.

With a note on the alarms and backup batteries, its also worth noting that if your alarm is old the backup battery can get knackered and not hold charge, when this happens it puts additional drain on the battery. This can be why one car will start up after 2 weeks of not running and another wont, all things but backup batterys taken as equal.

[DC33VN]

bought a hi powered century battery today was 169 dollars. had a problem with my positive battery terminal theres that much rust not even wd40 can undo the washer to remove it so i used a screw driver to slide it off the old battery then hit it with the back of the screw driver to sit back on the new battery