Make Your Own CMOS/RTC Battery

The HP Mini is back in the sick bay – the date/time keeps restarting back to year 2002 whenever the mini restarts. This must be due to the CMOS/RTC battery – after a while it becomes weak and is unable to save the date/time.

I went looking for a replacement unit but couldn’t find it at the usual IT shops I frequent. I gave up and thought I’d look for it online.

On my way back that day, I stopped by a stationary shop to buy some stationary. At the counter, I casually showed the old battery to the guy and surprisingly, the shop had it!

It was the same model (CR2016 – 3 volts) but without the connectors. I thought to myself – shouldn’t be that difficult to make my own using the connectors from the old battery.

Got the battery together with a PVC tape for electrical insulation.

IMG_00000198PVC tape, old and new Battery

IMG_00000146CR2016 – 3 volts

1. First I disconnected the power and removed the battery. Then I removed the 3 screws (marked in blue in the picture below) holding the keyboard.

The picture below shows the mini on its back. Turn in to the front and with the monitor opened (as if you were typing on it); gently push the keyboard screw extensions (marked in red) upwards to pop-up the keyboard.

IMG_00000184 v1 HP Mini on its back

 2. Once I removed the battery connector from its socket, I carefully cut opened the yellow tape from the old battery. Be gentle – don’t cut the wires and your hands!

Remove the soldered connector the same way.

IMG_00000192 v1Remove battery connector from the socket

IMG_00000210Carefully cut open the tape from the existing battery

IMG_00000211Slowly remove the connector soldered to the battery

2. Next I cut a small piece of the PVC tap into half and wrapped it around the new battery. I stretched the tape while going around the battery to make it stick better.

I believe the tape around the edges is to avoid the connectors from touching the wrong battery terminals.

IMG_00000213 IMG_00000214IMG_00000215PVC tape wrapped around the new battery

3. After that, fix the connectors to the new battery. Instead of soldering as per the old battery, I used the tape to fix the connectors.

Before I wrapped it, I bent the connectors slightly to make sure it touches the battery when taped.

IMG_00000217Bend the connectors slightly

IMG_00000220Put the bent connectors to the battery – red wire to ‘+’ terminal and black to ‘-‘ terminal and wrap the tape around the battery

  4. Finally fixed it back to the computer and screw the keyboard back.


It worked perfectly – no more date/time restarts. It was easy to do and it only cost me less than USD3 for both the battery and the tape.