What does trickle charge means? I have this app called "battery doctor" and it asks me to leave my iphone SE charging while it reached 100% for about 40 minutes!! Is it ok?!

Regardless of the Wikipedia definition, Apple refers to trickle charging as the slower, reduced current charging used to take the battery from ~80% to 100%. But it is not referring to any charging to maintain 100% capacity in the battery. It is simply referring to a reduction in charging current after the battery reaches about 80%.

See Batteries - Why Lithium-ion? - Apple

If you actually leave an iPad or iPhone plugged in for many days (and yes, I have done this myself when unable to leave home for a long period of time due to illness), you will notice that while continually plugged in the charge state slowly drops from 100% to somewhere less than about 95% - only then does it appear to charge once again to 100%.

Almost every consumer electronics lithium powered device I own (and have payed any attention to the charging cycle of) acts this way. If any consumer lithium powered devices actually use trickle charging to maintain full capacity of a battery once charged, I don't know of them. And it seems to me it would not be optimal for lithium cells to handle a full capacity state that way, from my understanding of their chemistry.

Its OK, your iPhone stops applying power to the battery after it reaches 100%. However, if you are using the iPhone when at 100% and plugged in, your iPhone will apply power in order to keep it at 100% charge.

You can leave it plugged in indefinitely. Once the battery is at capacity, all charging stops.

You are incorrect. Actually, any battery can be trickle charged. Although the Apple products include overcurrent protection you could use a charger without that. Batteries can be charged over 100% although not without endangering the battery. Apple's chargers do a form of trickle charging if the charger remains connected after the battery reaches 100%.

Trickle charging means charging a fully charged battery under no-load at a rate equal to its self-discharge rate, thus enabling the battery to remain at its fully charged level.

Yes, it's OK. Once the battery is fully charged the charger stops charging.

That is a low current level charge that will charge a battery slowly or protect a battery from losing charge while sitting inactive.

Numb__ wrote:

So what's the point of "trickle charging" ?!

I noticed when i leave my phone charging after it reached 100% it keeps more charge , should i do it every time i charge my phone?

See Batteries - Why Lithium-ion? - Apple

You cannot charge beyond 100%. That is physically impossible as once the battery reaches capacity (100%) all charging stops.

Actually, it won't. It will use the power from the USB adapter to operate the phone.

No, it doesn't keep charging if you are using the proper charger. What gives you the idea that it keeps charging? State your answer explicitly and thoroughly, please.

diodes123 wrote:

Its OK, your iPhone stops applying power to the battery after it reaches 100%. However, if you are using the iPhone when at 100% and plugged in, your iPhone will apply power in order to keep it at 100% charge.

No, there will be no active charging until the battery level drifts below 95%-90% of full charge. Only then does the charger kick back in and charge the battery. In a healthy battery, if left plugged in, it will take several to many days for the battery to auto-oxidize and drift enough from full charge to the point the charging circuits kick back in.

And none of that has anything to do with Apple. It is set in the industry standards for SMART lithium batteries. Your Mac behaves the same way, as does any and every device using industry standard Lithium cells, from tooth brushes to laptops to tablets to lithium battery carpentry tools.

Get rid of Battery Doctor. There is no such thing as trickle charging an iPhone; when it reaches 100% all charging stops. As the app proposes to do trickle charge, it is a fraud.