Has anyone come across this problem before ?

I have a 51 plate Alfa 147 (1.6 petrol) - the battery went flat so i have replaced it with a 075 battery (listed by some suppliers as the correct one) however the car will not work (blip locks wont work, computer states system failure and car will not start.) Tried a different 075 battery incase the battery was faulty - same thing. Also tried a 063 (from memory) and this doesnt work either.
HOWEVER - when i put the old battery back on everything including the computer works !! (Granted it wont start as there isnt enough power in the battery).
The numbers on the battery are slightly different to the one thats fitted (ah / amps) however these are the batteries listed for the car and i have been told should not make a difference !
I have worked on my own cars for years and have never come across this - any ideas ??????
The terminals are the right way around !
Any advice appreciated !

nb - as a quick introduction i also own a 79 vw camper, 94 ford probe and a 04 mazda premacy (the family car !) Have owned all kinds from a 1964 Rover p4 to Modified Toyota Supra Turbos etc. Quite like cars you dont see very often !

Is it something to do with the length of time you had the batteries disconnected. As you say, the actual battery can't make a difference.

Any numbers on the battery that was originally on the vehicle?

i have had a look in a book we have here and its listing an 079 / 012

079 / 012 40AH 330CCA 207 X 175 X 190

but saying that an 063 or 075 should of been fine since the that i see listed in the exide book is lower power.

seems strange it works on the old battery and not the new one really !!!

just make sure the ampere hour ratings are the same otherwise you may experience problems , i also know that its a bit of an oddball battery size on those alfa,s too so its possible you may have been given a smaller battery (wrong one )

but it still should work the keyfob though ??

if it helps below is the key programming procedure for alfa might be worth a try !!

1.
Arm and disarm the alarm sixteen times or until the alarm stops responding, alarm now in program mode.....
2. Once in program mode press the button of the new remotes(s), press the button of the original remote(s). This must be done within 8 seconds of each action. If 8 seconds pass without any actions the alarm will automatically exit programming mode and you will have to start from step 1.
3. Wait 8 seconds to exit learning mode.
4. Test remotes.

it cant be the battery, as long as the terminals are the correct way around any car battery will do for the electrics but may just not have enough uuumph to start the car if its too small, and won't fit correctly if too bit.
A battery is a battery, 6 cells of approx 2.2volts per cell. It must be something to do with the car electronics no liking the fact that you keep disconnecting it's power source and confusing it, no idea why its working with original battery, makes no sense as you say...

Thanks for the replies.
The old battery is an "exide" (with alfa romeo written across the middle)12v 60ah 320A.
Its on charge at the moment so i can use the car.
Really cant work this one out - like "diggingdeeper" said - wondering if because the new batterys are slightly different output and the old one has been off for a few days if the ecu / computer is confused ?
My next try is to find an exact battery that matches the above - if that doesnt work then i am all out of ideas !!!!!!

I meant the amount of time the car was without a battery, some ecu's reset after a period of time (some as short as 30 mins others 24 hour and some don't reset this way).

Ive seen this before on a citroën c5, I believe the battery has to be exactly the same, I believe the ecu sets itself up for the old battery ie amps etc, try swapping batteries whilst cars running, however making sure windows down so you don't lock key in! And obviously making sure you don't touch the body with the + lead! Run it for a while and it should work!

Some day a well meaning mechanic or naive jump start expert will attempt to disconnect your battery with the engine running. If you value your car and your money, don't let him!


The man from the road service thinks he's being helpful. After he can't jump start your car, he puts in his own known good battery and starts your car. So far so good -- your battery was definitely either run down or bad, and he's proven it.

Now he decides to "test" your alternator by disconnecting the battery. After all, the car's ignition should be able to run on just the alternator's power alone.



Wrong!

The moment he disconnects either lead from your battery, it's entirely possible he caused thousands of pounds in damage. Here's why...

Your battery does more than just yield electricity. It also shorts AC, spikes and transients to ground. Removing the battery from the circuit allows those spikes and transients to travel around, endangering every semiconductor circuit in your car. The ECU, the speed sensitive steering, the memory seat adjustments, the cruise control, and even the car's stereo.

Even if your computers and stereo remain intact, in a great many cases removing the battery burns out the diodes in the alternator, necessitating a new alternator. If disconnecting the battery interferes with the voltage regulator's control voltage input, it's even possible for the alternator to put out hundreds of volts, frying everything.

Even the initial premise was wrong. If you disconnect the battery and the car conks out, you don't know if it conked out due to insufficient alternator current, or whether the resulting transients caused your ECU (the car's computer, which controls fuel mixture, timing, and much more) to spit out bad data, shutting down the car.

Nobody should EVER run your engine without a battery.

And yet when you tell them not to, they'll roll their eyes. "I'm a professional. I do this every day. It's fine!" They'll sound so authoritative. So commanding. So intimidating. But they're wrong.

The problem, of course, is that disconnecting the battery doesn't always damage something. It does it only sometimes. Less experienced jump start professionals and automotive technicians figure if they got away with it a few times, it must be OK.

Don't let them do it on your car. When you call for roadside service, or take the car in for possible electrical problems, or have your battery and charging system checked at a "battery shop", give them this letter.

Thanks for the replies.
Put the old battery back on it tonight - started first time and i have just been out in it for a quick run !
The charge wont last though.
Will be booking it in at an alfa specialist tomorrow !!!!!!