Partial charge and battery life

[GrandSam]

I've seen a few posts regarding partial charges. However, I am confused as to how this may affect the overall life of the battery. I know most batteries have a charge cycle of 500-1000 charges/battery. Does charging a battery from, say, 3.4-3.9, stopping the charge, then starting again from 3.9-4.2, count as 2 charge cycles? Would doing so affect the battery?

I use a micro usb to charge my hana modz dna 30 (VTC4 battery installed), but sometimes need to unplug the charger midway. Could this harm the mods chip? Or battery?

 

[Baditude]

How to Charge and When to Charge? (Lithium Ion):

How should I prepare a new battery? -- Apply a topping before use. No priming needed.

Do I need to apply a full charge? -- Partial charge better than a full charge.

Can I disrupt a charge cycle? -- Partial charge causes no harm.

Should I use up all battery energy before charging? -- Deep discharge wears the battery down.

Do I have to worry about “memory”? -- No memory.

Can I charge with the device on? -- It's best to turn the device off during charge; parasitic load can alter full-charge detection and overcharge battery or cause mini-cycles.

-- Battery University

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"Li-ion does not need to be fully charged ... nor is it desirable to do so. In fact, it is better not to fully charge, because high voltages stresses the battery. Choosing a lower voltage threshold, or eliminating the saturation charge altogether, prolongs battery life but this reduces the runtime. Since the consumer market promotes maximum runtime, these chargers go for maximum capacity rather than extended service life.

-- Battery University

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"The most common USB chargers are designed for single-cell Li-ion. The charge begins with a constant current charge to 4.20V/cell, at which point the voltage caps and the current begins to decrease. Due to a voltage drop in the cable, which is about 350mV, and losses in the charger circuit, it is possible that the 5V supply cannot supply the battery’s 4.2V charge threshold. This is no problem; the battery does not suffer but will deliver shorter than expected runtimes."

-- Battery University