Hi, I am working on an old old original Canon NP-E3 battery that's in need of identifying the name of a defected component so that a replacement may be procure. I am thinking this is a fuse or something. At this point the camera (1D mk2) does not recognize the battery even with the fact that the battery is fully charged up (13.2 V) and keeping the charge. Back to 2008 when this battery showing signs of ageing (not charging or depleted quickly) I put it aside and purchased a third party HQRP replacement happy ever since. The Canon unit has been on the shelve all these years. Yesterday I took the NP-E3 out wondered what I should do about. In the beginning I thought individual cells were no good. I've read much about battery replacement and thought that's what I will do. Last night, thinking I've got nothing to lose, using a NC-E2 I refreshed and recharged it many rounds, amazingly, it reached 13.2 volts and holding. Sadly,when inserted the camera did not recognize it. Not power up. What I've done to it previously (in 2008) is opened it up removed the fuse resistor (I thought that's what went wrong) tested for con- tinuity forgot to solder it back lost it eventually. I've included here a photo of the part that's missing from the battery compartment. If you know what that is please let me know. Thank you !!!
Almost certainly a thermal fuse, I think your problems lie elsewhere,what is the square black thing ? Just because it charges up to 13.2 v means little because you need to know what the voltage is when it is fitted into the camera and current is flowing.
Thanks for the head up. I think it is a thermo fuse as well. I read somewhere that the breakdown temp is 93 degree C so I ordered one and waiting for it to come in. The black rectangular folder (shown in photo) , not sure what it is, may be a thermistor , has a metal blade running through. Since it is not burned or broken I assumed it is ok.
I doubt that it is a thermistor, looks more like a fusible link that would open in the case of excess current. Any chance you could could meter it to measure its resistance, if I'm right and it is still working then it should measure zero ohms in both directions.
I've got zero ohms when measured both directions. After repeating the discharging and charging process many times now I see the camera showing the battery is fully charged and I can take ten or fifteen pictures before it goes dead again. It so seems some or all of these cells are deteriorated to a point that they are unable to hold charge. It's been many years anyways. I'll go on purchase some new cells work on it from there. I think that concludes my adventure trying to revive my old NP-E3 battery. Many thanks to Ray-UK for his honest opinions and helps. Thank you again.
