Laptop external battery new. It loads but without network operation does the laptop turn off?

I replaced the external battery on my thinkpad p51s because it was no longer charged shortly after the internal battery. Although the new battery charges in mains operation and everything is displayed normally, the laptop goes out as soon as I disconnect the cable. It won't turn on without the power cord.

I don't know why and there's nothing in the user manual that I have tried.

Thanks to all readers. I look forward to your answers.

The ne battery whitelist deposited in the bios. You can't use everyone there.

That's annoying. I can't find a list of compatible batteries anywhere on the web. Does that only work with the original?

Only the original batteries are really supported. But there are also a few third-party models that apparently should work.

Of course there's also a workaround for it, but that's not for laypeople.

Difficult!

Let's break it down a little:

The fact is => the internal battery could no longer be charged!

It's also a fact => There are no external batteries, only power packs or charging cables!

So if buying a new charging cable (you call it "external battery") does not help as soon as you pull the plug, there's actually only one explanation left: The "real / correct" battery INSIDE the laptop is defective!

To be precise, it no longer manages the so-called "charge retention". This means that it can still carry electricity directly (as long as the plug is plugged in), but no longer save it.

Conclusion: You have to replace the battery that is in the laptop and everything will be fine again!