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Electronics repairs Toolbox => Electronic Component Testers => Topic started by: Kiriakos GR on June 27, 2026, 11:36:08 AM

Title: Can we actualy measure Battery Strap PolySwitch® PPTC Resettable Fuses ?
Post by: Kiriakos GR on June 27, 2026, 11:36:08 AM
This time the journey / research, this started by checking product specifications of a Samsung battery for mobile phones. EB-BG903BBE

At product description there is a reference, that within the battery there is a miniature Strap PolySwitch.
The next question this coming in mind, can we precisely measure Ohms resistance of such parts?

In theory this thing will look as a sort when this is not tripped.
From the other hand, this thing has 99% similarity to a current shunt.   

2026 Littelfuse, Inc. |  This makes it clear.
Most sensitive to low currents Resettable Fuse this is at 0.03 ~ 0.07 Ohms  1.9 to 4A protection range.

Long story in short:
We have a very low electrical resistance
Two wires measurement
And all handheld multimeter,  they are blind so to offer measurable confirmation due a measurement.
Lowest 300 or 600 Ohms range,  this cannot resolve / measure, such low resistance values.   


Two months ago, May 2026, I made to my self a special gift.   8) 
FLUKE TL2X4W PTII 4W test lead for FLUKE 8846A 6 1/2 DMM.

Due this combination, 10 Ohm DMM range + Four wire specialized test leads, I can now measure with high precision, anything within the Milli-Ohm quantities.

In conclusion, PPTC Resettable Fuses specifications verification, this is impossible due low cost tools.   :P


If you are after to get to know the entire truth?
This ITTSB article below, this offering true clear answers.
https://www.ittsb.eu/forum/index.php?topic=2300.0 (https://www.ittsb.eu/forum/index.php?topic=2300.0)