Hii frankbell, nice to see you again.

Yes, the cell battery... i know that . The laptop, as i have stripped it naked from back side :-p , there is no cell battery onboard. i believe this cheap chicky china cheap version of hp laptop is powered with capacitor only.. no cell battery.. thats my conclusion,.. hence i would expect it to reset itself when power drained for too long..
This was the case, the user just close the lid for 3 days without charging it. lol

Most systems have a settings panel available from the desktop gui that can set the system date/time and timezone so the user does not have to access the command line to do so. That method uses the timezone database with (in gnome) a click on the map to select the proper time zone. I don't know where that is on all systems but from gnome it is accessed from the icons in the upper right corner.

Regarding replacing any battery on the motherboard, sometimes this is a risky proposition. For instance to save obvious costs on a battery carrier, they would design a termination circuit which was integral to the PCB and solder the battery top and bottom, both to the board and to a fitting (stiff wire) on the top. I'm not sure soldering on the bottom is always done, they may use a conductive, heat tolerant adhesive, not sure. But I know the issue has come up from time to time and I sort of figured the lab technicians I've worked with are nearly magical talent people and it'd be no problem, only to find that I had touched a very risky subject and they informed me that it could damage the board. So they can contend with 201 size parts, but unexposed solder points such as slugs or under-soldering of things like the battery are difficult and they consider it a risk if it's not a board they have great experience with. And then there are some people who figure it's not a big deal and they've done it before.

Although what you're saying is that this capability may be replaced with a capacitor. Well I'd think that they'd design that to not result in discharge over a matter of days, however age or other factors could be causing it to discharge more rapidly. Still, unsure how you'd diagnose that without detailed design diagrams and schematic for the board.

I think if the problem of discharge is common, then either there's a method to mitigate it, by keeping it attached to a power source, or a way to reset it to the desired time each point where this happens.

I have never seen a replaceable battery to maintain bios settings on a laptop although they are common on desktops and servers. Since the laptop battery is always supposed to have power it usually would be a moot point, but the ones I have seen have an additional built in rechargeable battery for times when the main battery is removed or dead.

The OP said this happened when the user closed the lid with no charger attached for 3 days so the main battery was drained.

In any case, regardless of how the time got out of step, every bios I have seen in the last 30+ years has a way to set the date/time at that level. My experience goes all the way back to when an 80286 was a "late model" processor

Hi, The laptop is ok already. date is solved.

I'm not intending to be argumentative here, but I do want to point out that it's not necessarily correct to ask people to use NTP. In some cases it could be argued against using it, and for it to be avoided.

If your settings are correct you don't need NTP anyways.

I tear the whole laptop down to the pcb board.. looked for the cell battery, but can't find it. .hence conclude that it is in capacitor form.

Some of the Palm PDAs used button capacitors that looked exactly like button batteries. I don't know if those are still in use by any devices.