Author Topic: Revice some dead Camera Battery (Nikon EN-EL3e)  (Read 111 times)

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Offline nightfire

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Revice some dead Camera Battery (Nikon EN-EL3e)
« on: April 16, 2021, 10:28:40 pm »
Short Backstory: As I am doing photography, I still have some old Nikon gear lying around, that I intend to reuse for tinkering or some "high-risk" shots, where damage of the gear i no big concern due to low value.
On ebay I sourced some 3rd party batteries for a decent price, that are of the old type (LiION, 7.4V nominal voltage =2 cells internal) and no digital coding, only a small internal PCB for charge control and balancing. (And reporting back on a 3rd terminal the charge status to cameras with respective contacts like the D200 etc.)

Sadly, out of 5 used batteries only 2 were showing 7.4V, the three remaining were dead from the outside- my DMM showed 0.0xx Volts.
I cracked one open, and the cells measured 2.5 and 2.8 Volts, so they were about deep discharged.

As they were not only intended for powering a camera, but also to power (as second usage) some breadboard power supplies for tinkering (and eliminating power supply ripple...) I also might de-solder the 18500 cells inside and use the cells separately.
I mean those el cheapo power converters that can be clipped onto a breadboard and with 7.5V-9V input voltage they will provide 3.3V and 5V output- perfect for some things I will do some work with- and with a battery there cannot be ripple from a SMPS...

Questions:
- How good are my chances to manually revive those 18500 cells?
- Any good Li/Ion charger that could be recommended for usage with 18500 and 18650 cells? (Preferrably below the 50 €€€ mark...)
- What about manual charging via lab power supply?
- Any tips where to get in germany some 18500 battery holders (preferrably in one piece, no separate clamps for soldering onto a PCB)?


 

Offline RoGeorge

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Re: Revice some dead Camera Battery (Nikon EN-EL3e)
« Reply #1 on: April 16, 2021, 10:42:05 pm »
All consumer Li-ion batteries have internal protection against over-discharging, a MOSFET that disconnects any output when the internal voltage is too low.  Most of the time this is why Li based rechargeables show 0 volts.

Just let them in the charger for a couple of hours, and they might start charging normally.  It takes a while, so take patience, just let the battery pack in the charger and wait for it to start taking charge.

If you plan to replace the internal cells only, beware that some ballancing circuits won't work any more (will brake an internal fuse) if it detects a cell has zero volts internally (or disconnected).


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