If the motherboard battery is not lithium, that is, if you do not find the round flat battery the size of a coin we spoke about last week, that means your motherboard battery uses either nickel-cadmium (NiCd) battery or an NVRAM one.
The nickel-cadmium battery, unlike the lithium or the NVRAM ones, is a rechargeable battery, which means that in theory it should never need to be replaced. However, if your motherboard has a battery of that type and the computer shows the defects described last week (such as the loss of the hour and date), that means you will have to replace this battery. The problem is that replacing that type of battery requires some knowledge of electronics and some expertise, because you have to de-solder the old battery from the motherboard and solder the new one. That is why we recommend you seek the help of an electronics technician to do it, in case you don’t know how to use a soldering iron.
Figure 4: Nickel-cadmium battery.
The great problem of the nickel-cadmium battery is that it is very likely to leak, and that may even corrode the motherboard. In case the battery of your motherboard has leaked, you will have to clean the affected area using an old toothbrush and isopropyl alcohol. You will have to see if the battery acid did not corrode any of the motherboard tracks. If that has happened, the affected tracks will have to be remade using a wire. If you don’t know how to do that, look for an electronics technician.