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#1 (permalink)      11/17/2014 8:41:12 PM US Central   quote/reply + tips
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Question about charging Mah
I recently bought 2 nitecore d4 chargers. I don't normally watch my charger charge, but I did notice charging month old Efest 18650 3.7v 35A 2500 mah high drain batteries that when the level reaches 4.10v the Mah starts jumping up and down. It goes from 750mah, to 650Mah, to 500Mah, back up to 750Mah, and even as low as 100Mah til it reaches 4.20v. Is anyone else having this issue? Any replies would be greatly appreciated. Thx
#2 (permalink)      11/17/2014 9:34:39 PM US Central   quote/reply + tips
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pickles
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If you look even closer you'll see that it has also switched from CC (constant current) to CV (constant voltage). I don't know exactly what it all means but I'm pretty sure that it's normal. I have the D2 and it does the same thing.
#3 (permalink)      11/17/2014 9:59:57 PM US Central   quote/reply + tips
JPBel
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Explained better than i could -->http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
Some charger will stop when the current drop below a fixed threshole, other will give a toping charge.
Look like your's might be doing toping.

B.T.W
It is mA, not mAh
They are not the same thing.

Edited on 11/17/2014 at 10:02 PM. Reason:
#4 (permalink)      11/17/2014 11:12:30 PM US Central   quote/reply + tips
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Migweld
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+1 details
Basic Charging Methods

Constant Voltage

Constant Voltage A constant voltage charger is basically a DC power supply which in its simplest form may consist of a step down transformer from the mains with a rectifier to provide the DC voltage to charge the battery. Such simple designs are often found in cheap car battery chargers. The lead-acid cells used for cars and backup power systems typically use constant voltage chargers. In addition, lithium-ion cells often use constant voltage systems, although these usually are more complex with added circuitry to protect both the batteries and the user safety.

Constant Current

Constant current chargers vary the voltage they apply to the battery to maintain a constant current flow, switching off when the voltage reaches the level of a full charge. This design is usually used for nickel-cadmium and nickel-metal hydride cells or batteries.

Constant-current Constant-voltage (CC/CV) controlled charge system. Used for charging Lithium and some other batteries which may be vulnerable to damage if the upper voltage limit is exceeded. The manufacturers' specified constant current charging rate is the maximum charging rate which the battery can tolerate without damaging the battery. Special precautions are needed to maximise the charging rate and to ensure that the battery is fully charged while at the same time avoiding overcharging. For this reason it is recommended that the charging method switches to constant voltage before the cell voltage reaches its upper limit. Note that this implies that chargers for Lithium Ion cells must be capable of controlling both the charging current and the battery voltage.

Charging Small Capacity Batteries
When charging batteries with a capacity lower than 750mAH (e.g.
AAA, 10440 and 16340 batteries), a low charging current is
recommended to help extend battery life

To select a low charging current, while in regular charging mode,
simply press the side “SLOT” button to select a desired battery slot
and then press and hold the side “MODE” button for more than 1
second until “LOW” is displayed on the LCD display indicating
activation of low current charging mode. To exit, simply press and
hold the side “MODE” button for more than 1 second once again or
remove and reinstall the battery.

Fast Charge 2
NiMH dV/dt for/ Ni-MH AA, AAA, AAAA,, C types

Fast Charge 2
Nicad dT/dt for Ni-Cd: AA, AAA, AAAA,, C types


Charging LiFePO4 batteries
To charge LiFePO4 batteries, simply press and hold the side
“MODE” button for more than 2 seconds right after the battery test
completes and “LiFePO4” will appear on the LCD display to indicate
the activation of LiFePO4 charging mode. To exit LiFePO4 charging
mode, simply press and hold the side “MODE” for more than 2
seconds once again, or remove and reinstall the battery.

Nocturnal Charging Mode
When charging a battery overnight, nocturnal charging mode is
recommended. Simply press and hold the side “SLOT” button for
more than 1 second in any state until the LCD backlight turns off
thus activating nocturnal charging mode. This feature ensures a
peaceful night’s sleep without being disturbed by the D4’s LCD
backlight and blinking LEDs. To exit nocturnal mode and turn the
backlight on again, press and hold the side “SLOT” button for more
than 1 second again

Edited on 11/17/2014 at 11:23 PM. Reason: