My battery keeps going flat even after a short drive .. has done this for years even tho the battery is in good condition..

Most common that I've experienced would be corroded battery terminals and shorted plates. Corroded terminals will prevent power from getting from the battery to the vehicle. Shorted plates reduce how much power the battery provides under load (like starting).

There is only 2 reason for this to happen:
1. The battery must be in bad condition, in which case you should have it check up and if needed buy another one.
2. You car could have a short, meaning that probably there is a positive cable live touching the ground of the car. Therefor leaving your battery flat.
To troubleshoot and find out if it's a short, whenever you are to leave you car without a use for a week, just disconnect the positive cable of the battery, after a week, put it back on the terminal and start your car, if it start, then it's probably a short.

the alarm is going off because the battery is flat and in this condition the alarm system thinks that the battery is being stolen. Have a load test done on the battery and check that the terminals are clean and tight. Charging /replacing the battery should fix the problem.

When the battery is as flat as you describe then there will not be enough current for the ignition system. So you have two options before you go any further . Have a load test done on the battery to check for dead cell and if ok have an output test done on the alternator to see that it is charging the battery. Check the condition and tension of the alternator drive belt as it may be loose or slipping . If the head work included increasing the compression pressure then you will need a spot on battery to wind it over fast enough to start.

Change the battery in the fob first thing..is something draining the battery? or not charging the battery? Two separate questions.....

Check all fuses and relays, check all electrical connections, especially at the alternator..check for broken or corroded connections...check the tensioner on the drive belts...what is the condition of the battery? Is it holding a charge?

First are you sure the alternator is charging the battery ?
If it is, someone will need to pull fuses and disconnect major circuits until you find the drain. It could be a simple relay, or a short to ground in the harness somewhere.

no battery is
have a load test done on it

Instead of guessing as to what the problems is have it diagnosed at a qualified repair shop . Electrical testing needs to be done , charging system out put testing . voltage drop test electrical circuits . A bad ground wouldn't cause the battery to go bad , not charge properly is about all . Was the battery tested before it was replaced ? load and capacity tested ? What's the voltage Measurement at the battery with the engine running ? If the battery failed as many times you said it did , without testing i would suspect a over charge condition .That would be a guess without testing. The charging system on your vehicle is computer controlled .
Battery Common Causes of Malfunction
A battery is not designed to last forever. With proper care, however, the battery will provide years of good service. If the battery tests good but still fails to perform well, the following are some of the more common causes:
• A vehicle accessory was left on overnight.
• The driving speeds have been slow with frequent stops (stop-and-go driving).
• The electrical load has exceeded the generator output (particularly with the addition of aftermarket equipment).
• Existing conditions in the charging system, including the following possibilities:
- An electrical short
- A slipping belt
- A bad generator
- A bad generator voltage regulator.
• The battery has not been properly maintained, including the following situations:
- A failure to keep the terminals tight
- A failure to keep the terminals clean
- A loose battery hold down.
• There are mechanical conditions in the electrical system, such as a short or a pinched wire, attributing to power failure.

You need to take it to a good local mechanic who will put it on a fault code reader to wipe off the error codes which would of appeared from the battery going flat, any Good & Decent Mechanic will charge £20-30 for this less than 5 minute job, mines so decent he didn't even charge me for the loan of the code reader to sort my dads car on a Sunday, it's sluggish because it will have throw up a fault code of "multiple misfire" from the battery going flat, I had similar problem with my dad's Kia Sedona, I borrowed my friendly mechanics fault code reader & wiped the fault code off, done the restart again all was fine, hope this helps ????

Hi

Sounds like the battery to me.

Have they done a heavy discharge test on your battery at the garage, and can assure you it is 1OO% ?

The alternator is supposed to keep the battery topped up on charge nicely, even if it is only a few mile run every day, with your head lamps and heater going full blast, and then your fan runs on after switch off.
By the way it should only run for short time, how long have you heard yours run ?
Possibly the thermal switch is staying on too long ?

Did they test your charging rate on your alternator too, at your garage ?

How old is the battery ?

Is it of recommended type ? and not a cheepie from Halfords ?

Hope I have been of some help.

Good Luck

John.