If FET-based, yes. But if a plain simple cheap resistive 'PTC' then it can be significant. Not slating any specific suggestions on this thread - just saying watch out, and check the spec
I disagree.
I say Pptc resistance is the equivalent to FET based solutions and with the advantage of being two terminal and easier to retrofit.
If you parallel connect Pptcs to the quivalent trip current of the smart FETs the resistance comes out the same.
I crunched those numbers and started using them before ROHS was introduced in 2006. The clear advantages of Pptcs is why I never sold FET based breakers but, instead, gave Pptcs out like sweeties.
To put it in a way for those who can be misled by emotive statements, I pointed to a RGEF300 equivalent as a suitable device for Trucker in the original thread. The normal working resistance is around 0.035Ω. That makes 0.1 volt drop and not noticeable compared to NiMH battery resistance. If you look inside Ansmann 5-cell sub-c NiMH packs what do you see? - answer (Pptc protection)
The anecdotal mention of unsuited 100volt devices without important data is not worth chucking in any more than for 100volt Fet. Unless you made assumptions and didn't allow enough time to check.