Leaky Clock Batteries.

Most Amigas use a rechargeable 3.6 volt NiCd battery to keep the clock operating when the Amiga is switched off. These batteries deteriorate with age and start to leak corrosive fluids after several years. These fluids will eat away the copper tracks of circuit boards and destroy ICs and other components, ruining your Amiga. PCs don't have that problem as they only last at most a couple of years before they are thrown out and upgraded, long before their batteries have a chance to leak.

As even the newest Commodore-made Amigas are now over 10 years old, it is vital that the batteries are checked, and if necessary replaced. From my experiences, over 90% of all Amigas now have leaking batteries, so log out IMMEDIATELY and check your battery! If you don't, your Amiga will stop working one day and it may not be possible to repair it as part of the PCB may be dissolved away! . You have been warned!

One of the best ways to make your battery leak is to leave the Amiga unpowered for a long time. One one occasion I had an A4000 that had been used daily for 10 years. The battery never gave the slightest hint of leaking. It was then stored for two months, and when I checked the battery afterwards, I found it leaking badly. So, if you intend to store your Amiga for any period of time, you MUST remove the battery (unless it has already been replaced by a new NiMH type). Don't do what one person did - he stored two A3000s on their sides for 5 years. The batteries leaked and dribbled across the motherboard, leaving a frightful mess.

Note that these batteries contain cadmium, which is toxic. It is strongly advised to thoroughly wash your hands if you come in contact with any leaking matter from these batteries. For this reason it is also advised to not simply throw it out in the garbage but to dispose of it in a recycling facility that can handle old batteries and other similar materials.

How to spot a leaking battery.

The picture on the left above shows a typical leaking battery on an A4000D motherboard. You can see the white crud leaking out of the end. This is by no means the worst one I have seen (the owner wiped most of it off before I had a chance to take a picture of it). On the right is a battery in an A2000. If this picture won't convince you to check your own battery, then nothing will! As you can see the leakage is very extensive. It even penetrated into the CPU socket and was starting to corrode the CPU pins. As you can imagine, it is very difficult to clean it out properly from under all those parts. All Amiga models use similar batteries. They are all the same size and shape. They all leak eventually, especially if the Amiga is not used regularly. So, if you intend to store your Amiga for a long time (more than a few months), I strongly advise you to either replace or remove the battery first. Some 3rd party devices may have a "coin" type battery. These are lithium and are unlikely to leak.

If you have a leaking battery, it is vital it be removed immediately. Ideally it needs to be replaced by a new one. This will require soldering. Remove the motherboard from the case (after disconnecting the mains power!). Unsolder the old battery and clean all signs of spilt liquid from the area with some electronic cleaning fluid or methylated spirits. An old toothbrush is useful here. Using the toothbrush, scrub the area with some dilute vinegar (to neutralise the alkaline spillage). Finally scrub again with cleaning solvent or methylated spirits and then clean water. Don't forget to check underneath the PCB as well. If your motherboard looked like the one on the right, take a deep breath and submerge the whole PCB in hot water and scrub the area with a toothbrush and a dash of detergent after doing the earlier steps. Repeat and finish with a long rinse in the hottest water you can stand. Shake the board vigorously and leave it to dry in a warm place for a day or two. Solder in the new battery, observing the same polarity as the old one. It is a good idea to use one of the new Nickel-Metal Hydride (NiMH) batteries as they are far less likely to leak. If you are still using a NiCd battery, you may want to consider mounting it remotely and running wires to the motherboard so that if it leaks again, it will cause less damage. It is also possible to replace the battery with a lithium one. These last at least 10 years and do not leak. They are not rechargeable, so the charging circuit needs to be disabled, usually by placing a diode in series with the battery. There is a file on Aminet: hard/hack/lithbatt.lha with the details.

If you don't have the required soldering iron and replacement battery, or you don't have an electronics knowledge, take the board immediately to someone who does. To minimise the risk of any damage getting worse in the meantime, I strongly advise removing the battery by breaking it off. Bend it back and forth lengthwise gently until the battery breaks away from the PCB. Clean off all traces of gunk as outlined above. The Amiga will continue to function with the exception that the clock will need to be set each time on power-up. Some A3000 versions have some system settings stored in battery-backed RAM, they may need to be input each time on power up. A500 owners with the A501 expansion will need to remove the tin shield around their A501 before checking the battery.

Back to main Amiga page....but only after you have checked your battery!