18650s from a Dell battery

I just opened an old Dell battery I had, can someone identify what brand/capacity these are?

Although the laptop regarded the battery as dead, 3 of these batteries have less than 300mV, but the rest 6 have 3.96V! I don't have any other means to measure them apart from my DMM. Should I keep/use them or should I throw them also?

Those are LG ICR18650-B1’s.
They have nominal capacity of 2600mAh, and generally are very good batteries.
Keep ones that measured >3V, toss the remaining 3 ones.

So the 6 which read 3.96V, are they safe to keep?

Yep, just don’t use them in multi-cell flashlights (that usage scenario requires protection PCB). And make sure your charger is somewhat decent.

3.96 - should be OK, charge ’em and use them.

I salvaged 15 of these a few weeks ago.
3 were very low so I tossed them.
I’m using the rest, but have no idea of runtime yet.

Charged a couple of them, they go to 4.05V... so I don't suppose they'll last long... :(

What charger? Some chargers (like my xtar) charge all batteries to around their.

I used a TF TR006, usually it charges any battery just above (or around) 4.2V I think...

what laptop did this battery pack come out of?

Latitude D820