Question about batteries
- Thread starter barnacler
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I’m no electrical engineer, but I don’t think it quite works that way. Any rechargeable battery can be connected to a load and a charger at the same time. If the load demand is greater than the charger output, the battery will discharge. If the load is less than charger output, the battery will charge, of course at a slower rate than if there was no load. Problems can arise with the load and/or the battery if/when the battery is allowed to discharge completely and the system voltage drops too low, depending on what is being powered.
But is it like that the power is flowing IN from one side of the battery, and out from the other?
Sort of like a barrel with an outflowing pipe at the bottom, and a pipe flowing in at the top, and depending on the volume of each flow, the volume of water goes up and down?
Think of a cofffee urn with a tap at the bottom, and an open top. This is like your battery
The tap at the bottom is the outflow. Battery supplying loads.
Open it and the level in the urn will start to drop.
If you have another urn near empty, with coffee in it, you can pour that coffee into the first urn. Think plugged into a charger.
The level of the liquid in the first urn will rise if you pour in at a faster rate than the coffee that leaves by the bottom tap.
Not a perfect example. But a lot of electrical concepts are easier to explain using hydraulic analogs.
The tap at the bottom is the outflow. Battery supplying loads.
Open it and the level in the urn will start to drop.
If you have another urn near empty, with coffee in it, you can pour that coffee into the first urn. Think plugged into a charger.
The level of the liquid in the first urn will rise if you pour in at a faster rate than the coffee that leaves by the bottom tap.
Not a perfect example. But a lot of electrical concepts are easier to explain using hydraulic analogs.
Italian physicist Alessandro Volta was inspired by the electric eel to invent the first battery, the voltaic pile, in 1800. He studied how the eel's electric organ, composed of stacks of specialized cells (electrocytes), generated electricity and mimicked this stacked design with alternating discs of zinc and copper separated by saltwater-soaked material. The electric eel's ability to produce a continuous electrical current served as the model for Volta's device, which could produce a continuous electric current for the first time.
If the phone is consuming more power than the charger provides, the battery discharges to make up the difference. If the charger provides more than the phone needs, the excess charges the battery. If they’re equal, the battery neither gains nor loses charge
More like how a water tower works. The water used does not flow through the water tower. The tower is simply connected to the water main. Google “How does a water tower work?” for a more complete explanation.
No there is only 1 pair of terminals. A cathode and an anode.
So when connected, the charger supplies power to the phone’s internal circuits.
The battery is also connected to an internal power management chip, that measures how much current reaches the battery.
- If the charger provides more current than the phone uses, the excess goes into the battery
- If the charger provides less, the battery sends extra current out to assist.
OK, so what stumps me is this:
Let's say the battery is 80% charged. Not important.
It is being charged while at the same time it is being used, and the two amounts are precisely equal.
So , physically, it is presumably RECEIVING charge through the USB cable, lets say. That is PHYSICALLY the only location of the source of power, the inflow.
It is DISPENSING charge through I guess its screen, its connection with cell towers, the internet, wi fi, loudspeakers, and doing computations. I suppose it also creates heat. But the only route for DISPENSING power, isn't it ALSO through the same connections?
So the processors in the phone, the video screen, the antennae, the broadcasting device, the speaker, etc. are PHYSICALLY receiving power from the battery.
BUT...... as far as I can see, the connections of the battery to the phone is via copper connections, the SAME CONNECTIONS used to charge it. So if the demands on the battery are exactly equal to the CHARGING of the battery, doesn't that mean everything is still, and nothing goes anywhere?
Again, I see only ONE connection to the battery, both for charging and for delivering power to the phone.
Is there the ability WITHIN the CONNECTION , those little copper connections, for a stream of power to be coming in AND AT THE SAME time for power to be flowing out?
Let's say the battery is 80% charged. Not important.
It is being charged while at the same time it is being used, and the two amounts are precisely equal.
So , physically, it is presumably RECEIVING charge through the USB cable, lets say. That is PHYSICALLY the only location of the source of power, the inflow.
It is DISPENSING charge through I guess its screen, its connection with cell towers, the internet, wi fi, loudspeakers, and doing computations. I suppose it also creates heat. But the only route for DISPENSING power, isn't it ALSO through the same connections?
So the processors in the phone, the video screen, the antennae, the broadcasting device, the speaker, etc. are PHYSICALLY receiving power from the battery.
BUT...... as far as I can see, the connections of the battery to the phone is via copper connections, the SAME CONNECTIONS used to charge it. So if the demands on the battery are exactly equal to the CHARGING of the battery, doesn't that mean everything is still, and nothing goes anywhere?
Again, I see only ONE connection to the battery, both for charging and for delivering power to the phone.
Is there the ability WITHIN the CONNECTION , those little copper connections, for a stream of power to be coming in AND AT THE SAME time for power to be flowing out?
Your question is valid but it's EXTREMELY rare that power in vs power out is the same. That's why people mostly charge at night when power usage is at it's lowest because all their apps are off or not in use therefore charging can occur faster. In fact if the cell is turned off the cell will charge even faster since their no power draw from the cell being on. The same principal holds true for any rechargeable battery. BTW if using the USB cable, charge the battery using a wall socket connection instead of your computer because charging will be faster.
LTO_3
LTO_3
You are overthinking this. The short answer is no in the perfectly balanced moment in time you describe. There would be zero current to or from the battery. There would be current in the wires between the charger and the circuit(s) with load. I know my water tower analogy is a simplification (as all analogies invariably are). It certainly ignores the details of how either system is controlled. But in this case we are talking about flow, regarding water molecules or electrons. Electrons don’t flow through wires the way that molecules flow through pipes, but with direct current (which is what this is) the analogy works well enough. Single phase flow in a pipe (ignore multiphase flow for this) only goes in one direction at any specific point and moment in time. If there is flow to the battery (or water tower), it is charging. If there is a flow coming out of it, it is discharging. It’s that simple.
No, it is not.
Because I know that my phone can charge EVEN WHILE IT IS TURNED ON, so it MUST MUST MUST be going in both directions at once.
It is therefore SENDING current to the screen , antennae, speaker ETC while ALSO AT THE SAME TIME receiving charge.
You are all missing something.
Rate in minus rate out in a simple system equals rate of accumulation. We are dealing with charge in coulombs of charge in a battery system. Your analogy is a very good one. Are you an engineer?
If you take the removable battery out of a laptop while using it, the laptop still seamlessly works even though there is suddenly no battery.
Ie The battery in your phone does not have to be in line between the charger and the phone itself, it can be another load that the charger is providing power too if the power management is sufficiently smart.
The water tower makes the most sense to me.
OK, I get it, so the cable is supplying power to the UNIT in that situation and the battery is not involved at all, Ok got it thanks.
