Need to find OMD charger replacement

Started Oct 16, 2012 | Discussions thread
baxters
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Re: Do not trickle charge
In reply to Guy Parsons, Oct 17, 2012

Guy Parsons wrote:

The E-M5 battery is a new beast and charges to about 8.6V with the proper charger having 5 pins so maybe they manage to charge the two cells inside separately to get better results? Right now I cannot find any reference to any new technology incorporated in that new battery. Maybe it's just a factor of a new and more careful way to manage charging a battery?

The OEM charger puts out 8.6 volts when charging and it does remove it when charged (as do the Oly chargers fo the BLS-1) . There is more than one Lithium-ion chemistry so Olympus could have chosen one with higher nominal voltage to yield more energy. I recall energy goes as the square of voltage, so 8.6 vs 8.4 is maybe 5% more. It uses the same two pins as the cheap chargers to apply current. If any of the other three pins miss continuity, the charger will not charge.

My guess is that the pin in the middle of the two power pins connects to a thermister to give battery temperature to the charger and camera (which only has three pins). That leaves the other two pins for battery ID.

My knock off batteries appear to have nothing on the other three pins, so they don't sense battery temperature.

Batteries should have a protection chip to handle short circuits and abnormal charging. Ever had an nimH AA get warm in your pocket when it contacted keys and coins? A lithium cell could set your pants on fire if it ever short circuited, but the chip isolates it from the battery terminals when it senses a short circuit.

Even so, I don't plan to put the Oly battery in my cheapo charger. Charge rate is also part of battery longevity and the knock-offs may not have the right rate. If you get a knock off unit, the batteries are dirt cheap anyway, so there's no need to mix the brands.

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