What are these small white plastic things, that are in my laptop battery, between my laptop and the battery cells? Are they required if i change the cells?

 

Can be fuses, thermal fuses, thermal circuit breakers, resettable or not, necessary if you want to implement protection from mishappenings or circuit faults.

 

More importantly, it is to prevent a catastrophic fire disaster.

 

What are these small white plastic things

If you're NOT talking about the fairly obvious component, those white plastic things are insulators. They're there to prevent short circuits. If you're talking about the component with markings under the red marker - looks like a fuse to me as well.

 

That's likely a fuse.


That's an insulator.

 

Looks like tape to me. Is it sticky on one side?

 

Can someone explain, if the fuse/breaker/whatever is/are 'F' below, in what events or situations or happenings, how does it protect from the cells catching fire ? Is it for short circuits (+) to (-) ?

(+)------F-----(+)cell1(-)------F-----(+)cell2(-)------F-----(+)cell3(-)------(-)

 

It’s a Litttelfuse thermal cutout.
I think the one shown is re- settable in that it will open when it’s temperature exceeds 77 degrees C and will close when the temperature drops.
This particular part is obsolete, check out MPH-TA 15-9-77.
Without these components the pack is a potential fire bomb.

 

Can someone explain, if the fuse/breaker/whatever is/are 'F' below, in what events or situations or happenings, how does it protect from the cells catching fire ? Is it for short circuits (+) to (-) ?

(+)------F-----(+)cell1(-)------F-----(+)cell2(-)------F-----(+)cell3(-)------(-)

If the battery pack is overloaded or not charged properly the self-resetting fuse will open and hopefully prevent a thermal runaway condition (where the battery becomes a flame thrower if you've never seen a video of a lithium cell light off). I don't think it disconnects one battery from the rest, the battery pack should be a series of batteries. ANY thermal excursion will open the circuit and disconnect the battery from either the load or the charger.

 

What are these small white plastic things, that are in my laptop battery, between my laptop and the battery cells? Are they required if i change the cells?

Ask yourself this: If you are a manufacturer of laptop batteries, would you spend the money to put things in there that serve no purpose?