Alternator and battery replaced.... battery died 2-3 days later.

3 days on a new battery, yes it is significant. Four things can do this in a short time. alternator, starter, radio, and interior lights/ light switch. Alternator can be checked on the car, A sign for the starter is that it may drag or drag sometimes. Radio is lights staying on after the door is opened,Even the clock. Light switch is interior lights don't work or the dimmer switch doesn't work. These are just suggestions that I have run across. They still need to be checked. It can get costly.

have you had the battery checked to make sure it is holding charge if this is ok check the alternator charge rate

Just a couple problems I've had. dome light left on due to faulty door open switch, spot light charger or equipment left plugged or wired to battery, lately I thought I had a bad battery but I just need to clean the terminal connections. One more thing if your car is running you can pull the negative cable off the battery. If the car dies your alternator could be the problem. If you have a light in the trunk or under the hood you could pull the bulb out to make sure you don't have a faulty switch turning them on. These are kind of simple and that is the way I start out.

Hi

Yes it sounds like the alternator voltage regulator is wearing down and needs to be changed or replaced.

If you can get your hands on a 12 volt multimeter, turn the setting to 20 dc and place the negative wire on the negative battery post and the positive wire on the positive battery post.


The battery with motor off should be 12.6 volts and higher, start the the car the read out should be 14.,2 or higher.


You can turn the lights and heater on to see if the alternator can cope with the load.


if read out is less then you need to change or replace it.

Cheers

A battery from 07 is still decently new to be that bad, but I would check the alternator first, just get the car running and unhook the positive cable from the battery, if the car dies the alternator is bad.

Your alternator went out and when the battery dropped too low the vehicle died. Without the alternator and no battery you have no power to run the electronics. Have the Alternator tested to find out if it is the alternator or the Voltage regulator and replace the bad one. Then recharge the battery and start the vehicle. It is possible you lost a Main Bus Fuse in the power distribution box or an in-line fuse on the positive wire but based on what you said it is the Alternator.

Check alternator belt. Light is to show alternator working, not battery state.
If you have a volt meter check output is around 12.5 -14.5 volts when car running.

Something is draining the battery, Is the battery drained after sitting over night or within driven miles. If it drains over night power is being puled from a source, or the voltage regulator inside the alternator is pulling the power and draining you battery.

check power window relay and the interior light relay.

check the accessories fuse