Can I charge my 2.0A mobilephone with a 2.1A powerbank?

[steffeeh]

I'm currently looking for a suitable powerbank / portable battery, and I've found one that I want, though it has 2 different types of ampere outputs; a 1.0A, and 2x 2.1A - however my mobilephone is built for 2.0A

Normally a unit will try consuming the current it needs/wants even if the cable providing the power isn't capable of outputting that current if the electricity goes straight into the unit.
But according to a contact of mine who used to be an industrial researcher for batteries and fuel cells things doesn't work that way when we're dealing with batteries, that it's the power supplier that more pushes in whatever current is on the supplier's output, and that the mobilephone battery receives that ampere - unless it has a system adjusting it such as BMS (found in car batteries and UPS'es).
So if I were to charge a 1.0A mobilephone with a 2.0A charger the I will push 2.0A current into the 1.0A battery - which means it will charge faster (which it really does in the real world to my experience), but it may perhaps decrease its lifetime and increase wear and tear - at least according to this person that I know, however numerous other people I've talked to suggests there is no harm in this... so I get a bit confused.

There is a lot of value in a lot of people suggesting I shouldn't be worried about it, but on the other hand I have a person I know that is more or less an expert who suggests that it may put the battery under extra stress.
In my particular case I have a mobilephone at 2.0A, and a powerbank of 2.1A - is there any risk that the extra 100 mA can decrease the lifetime and increase the wear and tear of my phone battery?

 

[Eximo]

Standard car batteries don't have a BMS system, just an alternator that shoves voltage into it. They stop charging when the voltage difference stops. Hybrids and EVs do, but that is because they have Lithium battery packs.

Lithium cells and batteries are inherently dangerous, excepting a few less energy dense chemistries, as they can catch fire and explode when overcharged.

Without exception all consumer products that contain Lithium cells or batteries have a management system. Usually in the form of a small integrated charging and regulation chip that is an off the shelf part. The circuit will regulate what the battery takes in. That is how they know when to stop taking in power and start maintenance charging.

So you could have a 10amp charger, and plug a lesser pack into it, an actual measurement would show the regulation circuit taking the input and chopping the signal, so short bursts to get an RMS value equivalent to the desired input.

Comes down to maximum charge rates and temperatures. If the battery gets too warm, it will slow down. It will not exceed the maximum C rating (10C = 10 times battery capacity, a common rule with Lithium, but parallel cells can completely change that.)

 

[InvalidError]

Normally a unit will try consuming the current it needs/wants even if the cable providing the power isn't capable of outputting that current if the electricity goes straight into the unit.

Mobile phones and tablets have a built-in power management and DC-DC converter chip which takes the 5V from USB, drops it to the 3.5-4.3V required to charge the battery and provides the various other voltage required to operate the phone/tablet's other components.

That chip will usually monitor the input voltage and throttle the current it draws to prevent that voltage from dropping too low. If you connect your "2A" phone to a 2.1A charger using a cheap USB cable and measure the current actually going through the cable, you may find that your phone is current-limiting itself to something like 400mA due to voltage drop across the cable.