Author Topic: EN-EL15  (Read 2327 times)

DanAa

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EN-EL15
« on: April 05, 2019, 21:38:53 »
What does it mean when during an attemt to charge my EN-EL15 battery using the standard MH-25A charger the LED-light flashes rapid (more rapid then normal charge). There seem to be no charge occurring. The battery "is flat". Is the battery "gone"?

Birna Rørslett

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Re: EN-EL15
« Reply #1 on: April 05, 2019, 23:19:02 »
Might be a forced discharge initiated. Leave the battery in the charger for a good while unless it gets very hot or starts to smell funny.

Alaun

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Re: EN-EL15
« Reply #2 on: April 05, 2019, 23:54:05 »
No, that might be dangerous.
Check the temperature of the batteriy. It might be warm. Take the battery out of the charger and let it cool. Replug the charge as well. If the blinking persist, soemthing is wrong. ( from the manual)
Wer-      Dro-
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Øivind Tøien

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Re: EN-EL15
« Reply #3 on: April 06, 2019, 05:17:57 »
Might be a forced discharge initiated. Leave the battery in the charger for a good while unless it gets very hot or starts to smell funny.

Li-Ion batteries never need to go though full discharge cycles, quite opposite, fully discharging them might damage them, and a good charger should then refuse to charge them. That is why the bodies have cutoffs listing them as "empty" (0%) well before they are completely discharged and reaches the very steep discharge curve towards zero voltage. Zero voltage can be very dangerous in multi-cell Li-Ion/Li-Polymer batteries if the charge is not properly balanced among cells, as it means that some cells get into reverse voltage where very bad things can happen.

A charger complaining could be problems with the built in chip, but also inability to balance the charge between the cells, for instance if one cell is going bad or the charge balancing circuitry is broken.

BTW, one sometimes sees questions if the new EN-EL15b batteries can be charged in the MH-25 (non-a) charger: I can confirm that my newly purchased EN-EL-15b (the only type that was available locally for my D500; vendors like B&H and Amazon refuse to ship them to Alaska) reaches 100% charge in both my MH-25 (non-a) and MH-25a charger. The first use of the EN-EL15b discharged down to 41% in the D500 before I recharged it again gave me 1367 frames, so with the same use (lots of high speed shooting) it can be extrapolated to 2317 frames for a discharge to 0% in that body. 8)  I believe this was rather the result of the usage pattern (total on time), not the Li-Ion 20/a or -b battery type.
Øivind Tøien

pluton

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Re: EN-EL15
« Reply #4 on: April 06, 2019, 07:41:23 »
In the instruction sheet for my MH-25 (not '25A', but presumably same operating principles), the rapidly blinking light indicates:
1.Battery not correctly inserted
2.Operating temp range exceeded (0ºC to 40ºC)
3.Battery malfunction.  In this last case, Nikon instructs to unplug and take battery and charger for service.
Keith B., Santa Monica, CA, USA

Øivind Tøien

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Re: EN-EL15
« Reply #5 on: April 06, 2019, 08:40:14 »

When this thread started, I got the idea to try to charge a defect EN-EL15 (Li-Ion20) I had not disposed of yet in my MH-25a charger as I had not tried it there yet, and I wanted to see how the charger reacted. For a long time I had some hopes up (wishful thinking was that somehow the charge had redistributed itself from the low to the high cell) as it responded normally with slow blinking. Well that went on an on, and tonight after about 12 hours it appeared to finally have given up and responded with the very rapid blinking. I suspect that when that happens, safety kicks in and there is no more attempt to charge the battery. My D7100 reported 1% charge, age 4, and while I could fire off a few shots, the battery is obviously gone.
Øivind Tøien