Car Battery Dead

[sky-017]

my car battery is completely dead , i have d/c the positive lead from it because my alarm wont stop sirening . this is probably the back up battery for the alarm . and everytime i connect it , it keeps making the siren .... hence the car is dead .

what am i to do next ? im stumped . im considering calling the NRMA , but if i cant do anything what could they really do?

any answers would be great ?

[Duke_R32]

buy a new battery or charge the one you have now.

there a three reasons a battery goes flat, alternator not charging properly, a current draw or a dud battery.

if ur a NRMA member then give them a call as they can help u

[sky-017]

will they be able to charge my car battery - or would i need to take it somewhere..?

the altenator isnt charging , is that flat - that you dont even hear it click when you start , so faint of a noise compared to the loud click

[lingeringsoul]

my old man said if you get it started, drive it around for an hour and then can't start again then the alternator is f**ked.....otherwise something must be draining it

[JonesyGTR]

my old man said if you get it started, drive it around for an hour and then can't start again then the alternator is f**ked.....otherwise something must be draining it

It could also be that the battery is cactus. Thats what happened to me, it would ONLY JUST start after an hour driving around. Then got a new battery about 2 weeks ago. No issues since then.

[sky-017]

this all happened because i had the stereo left on for a few hrs .... jumped it twice since then , but havent fulley charged it cause i cant drive for another 4 weeks .. so its gone flat again , because one nigth i went out and was working on my car and had headlights on ... drained again ... although , the other day i walked by my car and checked the door if it was locked , and the alarm sounded cause it was armed and opened ..... the remote wouldnt shut it off , cause no power - so i dcd the battery ..

i doubt the battery is gone , i think its just completely dead ..... and to the point where it wont charge through a jump .

how much is a new battery? if i called NRMA they could bring one , so iv heard...

[Duke_R32]

between $30 for a super cheapy to $120 for a decent one.

(the more you pay the more plates per cell you get in your battery)

i suggest if you have a problem of draining your battery you should invest in a battery charger.

to check the charge rate, start the vehicle grab a multimeter and set it onto voltage.

turn off all your lights and air con and place the multi meter on the battery if its reading a constant high 13V or low 14V thats good, now put some load on the battery by turning on your stereo or lights and do the same as above it should now read a constant low to medium 13V.

thats the most accurate way of checking if your alternator is working.

to check for a current draw have everything turned off inc your ignition. disconnect the negative battery terminal. now set your multimeter to amps and place one multimeter cable on the battery post and one on the terminal. your multimeter should be reading 0.10 -0.01amps if its around 0.2 or higher then there is a current draw.

to find out where the current draw is coming from keep the multimeter as above and start removing and re-fitting your fuses one by one until the draw goes away.

this just narrows down all the possibilities of what could be drawing current.

[sky-017]

i just took the battery out and called the nrma , on the battery the light is red , which sais it shouldnt be recharged . so its blown .

also it needs to be replaced by the looks , the date is up .