Battery goes flat

alt died
then in 30min driving the battery dies and engine stops
the engine run off the ALT full time until the ALT dies
causing rapid battery discharge. and engine stalls.

do not replace the alternator with battery NEG lug connected of blow up ALT FUSES, never fun that.
or on newer smarter alts , it shuts down if 1 battery cell of 6 goes open or shorts, this prevents battery explosion.
so we load test the battery first. then if good the alt is bad. or we test the alt next.
this failure is super common , for 100 years.
we test the both carefully

the alt good will put 13v to 15vdc on the 2 battery lugs.
even at idle, and any dmm meter made can see that.

well the battery is now dead (or only discharged !)
cause #1 ALT/Gen replaces WRONG, see here 10,000 times. more www.

driving a car the ALTERNATOR produces all Electrical power.
100amps x 13v is 1300watts, and runs ALL>
when it dies the battery is sucked dry/dead/ discharged.

1; remove neg lug from battery or BOOM (100amp fuse BLOWN)
2; remove ALT
3: new one back connected same.
4: battery NEG lug back
bingo no BOOM.!
every SM manual of every car tells that;.

you said didn't want to start
but I guess you meant starter is dead, or clicks only or will not spin fast as it must.

the 15mins is dead accurate, for 50 years driving seen this happen
as ALT goes dead at night,
in the day engine runs 30min to 1hour dead ALT , HEADS off

the blow fuse is just bay fuse
or worse, a fuseable link, oddity not fun to fix. ever.
thus step 1,

no engine told but let me look on uSA car thjis.
2010 not AVEO5

there it is but what it looks like, hummmmmm

First off ck to be sure it needs a alternator start car test battery voltage at battery w/ car running in park should be close to 13 volts at battery if not ck alt fuse if ok replace alt.by removing radiator and cooling fan assembly to gain access to alt

You have something drawing on your battery. disconnect the nevagative cable. hook a test light between the negative cable and negative battery post and pull fuses till the test light goes out. when the test light goes out you've found the circuit that's drawing down your battery. trace the circuit and look for a short to ground or if something on that circuit is staying on.

The Charge lamp comes on with the Alternator fails to keep battery charge going. (lots of way to fail, and ALT Is 100% good) it's a system. each part of it must be good, end to end.
so...
i put my voltmeter across battery, i start car, i see 13.3 to 15vdc, alt is good.
no? , i see now, 12.2v. ALt is dead, (i didnt say bad) and battery is sightly discharged, 12.6v is charged. (key off, rested voltage)
This 12v tells me the ALT is shut down. only why is the question.

how can any charge system fail,
bad battery tops the list here, they LOVE to fail.
1: belt slips.
2: belt missing
3: bad alt.
4: bad wires to ALT . (corrosion on any wire or lug)
5: fuses blown , any listed below.:
your alt is not an ECU controlled, alt ,its 100% self contained

did you ever remove the ALT and blow the 100 amp fuseable link
the first step of any alt pul, is the pull the NEG, battery lug or BOOM.

im logged in to alldata.com so can you.

and what do i see.
a 5 wire ALT. one is the frame ground, so it must not be rusty or..... it fails. frame to engine block. no rust here.

wire L , yellow.goes to dash LEDs (alt failure idiot lamps) (this works)
wire. S white goes to ALT 5a fuse, is it blown?
wire :B B/G color, goes to the 100 amp link fuse. (blown>?)
wire IG Red-white, goes to a fuse marked 10A gauge.

i think the IG wire is the voltage sense wire.
no sense, no charge. I think the whole I/P dash cluster goes dead when this fuse blows.

The S wire is the boot strap voltage sense, it wakes up the regulator .
if open , the reg stays asleep, as does ALT.
Alternators can not self start, the regulator has boot strap device
that cures that. called self excitation. so this wire is critical.
All wires except the L wire is critical. in this case.

the B wire is the big wire, it charges the battery . 50amps or more..

any of the 5 paths open , kills the ALT dead.
The REG inside the ALT can also shut it down.
eg: battery bad, with huge cell resistances. total.
eg: overvoltge for any reasons. including attempts top run car with no battery, (dont ask)
eg: over current (battery cells 1 to 6 shorted) or 25 KC lamps added.
eg: over temperature shut down.

that is about it.

The battery needs 12.6 volts or more to be in service
When the engine is running you need 14 volts or more
out of the alternator to charge the battery
You can test the alt by testing across the battery term
or the alt output wire & ground to case or motor
Could be the diodes got fried & you need a new alt
Have it tested at parts store, if you can't figure it out
Check all fuses & fusible links first

OK....Since you've tested ALT & BATTERY?..Then you should inspect that missing fuse for horn and see if maybe it's been put in as a replacement in a port for anything to do with charging system,ie: alt,battery or other?....Then check ANY fuse links on the wiring/battery cables and other like to altenator etc....If you dont know what a fuse link is,most times it's on the hot wire that goes to starters,close to it,and to explain what it is--it's a short length of wire that is smaller,like a filament,like a bus fuse,cept these are coated and you cant se theyre blown,you have to do a continuity test to see if filament type wire isnt broken.....Another thing you may want to try is ADD an additional body ground wire from battery negative post to body of vehicle.I had a 71 Monte Cralo way back and I went through a similar thing and NO electronics thank god! But I added a fresh,thick wire from battery to body heavy bolt type screw and problem was solved....Hope I ahave helped,please post if it did...Thanks JD

The charging system in your vehicle is computer controlled ,checking for DTC'S - diagnostic trouble code's should alway's be the first step in the diagnostic process ,testing for B+ voltage at the wiring connections at the alternator would be the next step if no DTC'S are stored . The single heavy gage wire on the back should have Battery voltage , the wire's at the connector ,three out of the four should have B+ voltage an the # 3 wire is the control circuit from the ECM - engine control module . Four fuse's supply B+ voltage to these connections . 10 amp gauge #1 , 7.5 amp gauge #2 , 7.5 amp ALT-S an 120 amp ALT fuse. If any one of these is blown the alternator won't charge . If you know nothing of automotive electrical system testing ,your best bet would be to take your vehicle to a qualified repair shop.

You need to pull fuses to see,but it can still be the alternator,with a bad diode allowing the drain,remove the negative battery cable from the battery,then buy a test light,they are cheap,clip one end to the negative battery cable,and touch the tip of the test light to the battery post,and the test light will light up,cause there is a draw on the system,make sure the doors are shut,and the lights are off.Then unplug the connector on the alternator,if the test light light goes off,the alternator is the problem,if not,remove the dome light fuse,and start pulling fuses one,at a time,and putting them back in,as you go,if you pull a fuse,and the test light light goes out,that is the circuit that is drawing the voltage from the battery,leave it out,and hook cable back up,and see what does not work with the fuse still out,and that will be the problem,please rate if this was at all helpful,thank you.

When it is running,put a volt meter across battery terminals. You should see 13 + volts if alternator is working. Also put an ampere meter in series with a battery cable,key off, engine off, and you should see less than 40 to 50 Mili-Amps. If more,start pulling one fuse at a time,untill you find the circuit that is draining the battery