Laptop abruptly switches off when exporting vid on battery

Hi!
My old laptop died and I bought a refurbished Dell XPS 9560
Yesterday I started using it for DaVinci, and the laptop switches off abruptly (as if someone would have pulled the plug from a desktop) randomly when on battery power. Battery indicator at that moment can show anything from 60 to 98%. It refuses to start again while on battery, but if I plug the electricity cable in then i can start it. It has not switched off with AC adapter plugged in.
The fans werent sounding much before switching off, and I generally doubt it is overheating.
I ran the Diagnostics from BIOS, no issues. Battery health 96%, battery manufacturing date 6/4/2021. I also ran battery check from cmd, design capacity and full charge capacity corresponds to battery health 96%. Have updated BIOS, with Dell support app have ran all the diagnostics, checked and installed all drivers. I can find no issues.
At least two of 3 switch-off events happened when i was exporting a vid. Googled, people write such stuff could be CPU or MB overheating, - but then for me it does NOT happen if i am on AC power, so I doubt its overheating..
I checked the reliability report. Now, I dont know what most of it means, anyways when DaVinci stopped working, every time the problem event name was BEX64, and fault module ntdll.dll

Can it be overload? I have 16gb RAM, intel i7 (4cores) 2.80GHz, Nvidia GeForce GTX 1050 4gb.
Drivers???? Anything with ntdll.dll? Any ideas would help. I need this laptop to work; if I return it to the vendor I might not find another one here in Sweden that fits my specs

BEX64 is an indicator that a third party application has crashed. The ntdll,dll points to an incompatabilty somewhere. Possibly your GPU driver. You can check for updates on nvidia.com.
As to battery vs mains power, rendering uses a lot of processing and hence more power. It is possible that your battery can no longer hold a decent charge when under load, hence the shutdown.

Probably the battery has not enough power for the energy requested by the system. But a switch off should not occur.

You might get some help in this forum in the Dell topic.
https://notebooktalk.net

Thank you!! I will be checking out the ntdll.dl error, but it really makes sense that it could be the battery even if it shows good health. It would make sense if it would crack under pressure, because on AC power the laptop runs fine

In my experience, the only laptops that work well with DR under battery are recent MacBooks.
Older MacBooks and all Windows laptops should be on mains when rendering.

Windows laptops should be on mains when rendering.

+1 - even with a new battery!

In my experience, the only laptops that work well with DR under battery are recent MacBooks. Older MacBooks and all Windows laptops should be on mains when rendering.

Yeah, rendering is a very high-stress situation, and we actually had to replace a 2000-watt UPS with our big Mac Pro on some difficult jobs. Now, we have a 3000-watt model and the problems disappeared.

In my experience, the only laptops that work well with DR under battery are recent MacBooks.
Older MacBooks and all Windows laptops should be on mains when rendering.

This is a very very interesting and potentially crucial info for me!

It might mean that I might not have to return the laptop to the vendor and I might keep it, because the battery is not faulty, only weak.
I dont find any problems whatsoever with the system, the only thing is that I can render with speed 10fps but if I try with max speed, the laptop shuts down as if I'd have pulled the plug, and doesnt start again unless I connect AC adapter. I guess the crucial question is - can a new but weak battery react to too high demands so that it abruptly switches down the laptop and refuses to start unless I connect it to AC adapter? If yes, and you guys recognize this, then I have my answer.

P.S. I used to have a beast, which was a ROG with amazing power, so I could render on battery with that one, but it died (and Im still mourning it, obviously), and Dell XPS 15 9560 that i have now is just soso

But the system as a whole should not crash, at most it should only crash the application and even ideally only the job.

That's true, it should give a warning and shut off. Might be some basic weakness in electrical design.

I might have found the problem and the solution!
THE POWER PLAN. In the power plan the cooling fans were inactive in battery mode (advanced power settings - processor power management - system cooling policy(battery) - it was set to Passive and I changed it to Active now). The laptop switched off in a typical overheating fashion with no warning when CPU was on high load and heating up, but the CPU cooling was inactive and on passive mode when running on battery!! It was CPU overheating!
I did a short export (but using corrections in Fusion therefore demanding) already with the cooling on (in active mode), on battery power, and the laptop didn't switch off! I will still test but I think this was the problem!

Thanks for the solution. might be helpful to others.