– Can someone please explain those acronyms and how are they related to each other ?


WH, AH , V

I would like to understand how to read those numbers and see how many times a power bank charger can recharge my phone or laptop.

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Watt-Hours, Amp-Hours, and Voltage

Voltage is a measure of electricity. The more volts, the higher the power, which relates to the amps and watts.

Your average regular phone charger will be about 5V, while a fast charger can be 50V or more. For comparison, a AA battery is rated at 1.5V

Amps are a measure of the amount of electricity used.

To make an analogy with water, voltage is the speed of water going through the pipe, amps are the amount of water flowing through it.

More volts correlates to more anps. Amp-Hours is a measure of how much power your device gives or takes in a period of time.

Watts is the combination of voltage and amperage. You multiply the two to get the wattage. This would be the equivalent of measuring the pressure of the water in the pipe. Increase the speed of the water or the amount of water, and you increase the force of the water.

Many light bulbs are measured in Watts, and overall power consumption is measured in Watt-hours or Kilowatt-houra.

V – Voltage is equivalent to electrical pressure. That is, “how hard is the power source attempting to push electrons through the circuit”

A – Amps is the actual resulting flow of electrons. The more electrons moving through the circuit, the higher the amperage.

AH – Amp-Hours is a measure of amperage over time. So for example

`2 Amps x 1 hour = 2 Amp-Hours.`

`0.5 Amps x 5 hours = 2.5 Amp-Hours`

W – Watts is a measure of power at a given moment. Power is defined as Voltage (V) x Current (A). So for example:

`120v x 0.5A = 60 Watts`

`220V x 15A = 3300 Watts (or 3.3 Kilowatts)`

WH – Watt-Hours is a measure of power over time, similar to Amp-Hours.

Wh is Watt-Hours, Ah is Amp-Hours, V is volts.

To explain these you need a bit of basic physics. If you have some current flowing (measured in amps) across some voltage (measured in volts) then the power (measured in watts) is equal to the current multiplied by the voltage. We’d write that as P=IV Where P is power, I is current and V is voltage.

Batteries store electric energy, which watt-hours are a measure of. 1 Watt hour means it can supply a power of 1 watt for an hour (or 2 watts for half an hour or 3 watts for 1/3 of an hour etc). The thing that determines how many times it can recharge your phone is the energy capacity of the battery, and that of your phone. If the energy stored in the battery is 4x that of the phone battery, you’ll get close to 4 full charges out of a fully charged battery (not quite 4 due to inefficiency in the charging process). Amp hours are a related concept, its a measure of the electrical charge that the battery can transfer, 1 amp-hour means it could supply a current of 1 amp for 1 hour. You can convert this to the energy stored by multiplying by the voltage to go from amps to watts (using P=IV).

If you know the voltage is going to be the same, then you can compare batteries based on their amp-hour ratings.

How many volts something gives . Commonly 5V but can be higher for things such as fast chargers or laptop chargers. 9v is fairly common for quick charging and 19v is fairly common for a laptop power adapters.

Ah-amp hour
How many hours a battery can power a device with a specific draw. If you have a 5ah battery and you draw 1amp then you should get roughly 5 hours of run time.

Wh- watt hours
A watt is your current (amps) multiplied by your volts. If you have a 9volt 5amp hour battery then you will have a 45watt hour battery. If your battery was 10 amp hours then it would be 90watt hours

I would compare everything in watt hours if you can as that removes the complexity of volts and amp hours but take any specs with a big grain of salt as the numbers are usually up to’s and there can be a lot of inefficiencies and losses.

WH – Watt-hours

AH – Amp-hours

V – Volts

A common intro analogy to electrical flow in wires is to liken it to a fluid in a pipe. It’s not a perfect analogy, and it starts to break down when you get into the specifics, but for a really basic understanding, it’s pretty intuitive and useful.

Voltage is analogous to pressure. If you have a high pressure on one side of a pipe, and a low pressure on the other, fluid will flow. Similarly, if you have a high voltage on one side of a wire, and a low voltage on the other side of the wire, electricity will flow. The higher the voltage difference, the faster the flow, same with pressure.

If you put too much pressure on a pipe, it can burst. Similarly, if you put too much voltage difference a wire, it can melt or burn up. So a device’s V rating is essentially telling you what its “pressure rating” for electricity is. Don’t exceed it, or you can fry out the device.

Amperage is analogous to flow rate. In a pipe, you can measure how much water has moved through the pipe in a given unit of time. Amperage tells you how much electric charge has flowed through a wire in a given amount of time.

If you multiply flow rate by time, you just get an amount of fluid. If I had a pipe that has a flow rate of 1 liter per minute, and I let it flow for 5 minutes, I’d have 1 * 5 = 5 liters of water. So, multiplying amperes, a sort of “flow rate” for electric charge, you’ll end up with an amount of electric charge. That’s what an Amp-hour is. It’s a slightly convoluted way to tell you how much charge potential a battery can store. If a battery holds 100 Amp-hours, that means the battery can (in theory) deliver a consistent flow rate of 1 amp for 100 hours. Or 100 amps for a single hour. Or some other combination. The voltage you apply will determine how fast it will flow, and since you have how much charge the battery has in total, you can calculate how long it will last for a given flow rate. Just like how if you had a tank with a known amount of capacity, and a drain in the tank with a known flow rate, you can calculate how long it will take for the tank to be empty.

Watts are a unit of power. It describes using a certain amount of energy over a certain duration of time (specifically, 1 Joule per second). In a way, it’s a “flow rate” for energy. So, just like with the amp-hour, a watt-hour is a slightly roundabout way to describe an amount of energy. This tells you directly how much energy storage capacity the battery has.

As others have stated, it’s watt-hours, amp-hours and voltage.

Voltage will typically be constant in a phone battery pack, although it may change depending on whether it’s smart enough to communicate with your phone and go into “fast charge” mode If it’s an older/more basic one, it’ll probably have a constant voltage of 5v.

However, watt-hours and amp-hours are measuring related but different attributes.

Put very simply, amperage is “how much current is flowing” and wattage is “how much work is being done”. When we measure watt-hours and amp-hours we’re essentially saying “this device can provide x watts for y hours” or “this device can provide x amps for y hours”.

For the purpose of a phone battery pack you’re more interested in the watt-hours measurement, although the amp-hours one may also provide some insight- if the phone has a “fast charging” mode, it may draw much more current and charge faster, but at the cost of total charging ability due to losses from the device working so hard.

One watt-hour on a 5v battery pack would be 0.2 amps for one hour. Many phones with a “fast charge” mode will try to draw far more current, so if your battery supports it, it might draw far higher currents, 2.5 to 3 amps at 12 volts, which would be about 30 watts.

Wh is Watt-hour. Its a unit of energy. 1 W = 1 J/s , 1 J/s × 3600s = 3600 J = 1 Wh is not a large unit of energy so we often use 1 kWh = 1000 Wh.

Ah or Amper-hour is a unit of charge. 1 A = 1 C/s , 1 C/s × 3600s = 3600 C (Coulomb) = 1 Ah. 1 C is a gigantic amount of charge so usually we use 1 mAh = (1 Ah)/1000.

V is voltage. Its the potential of an electric field. Potential is the Coulomb force action on a 1 C charge at a given point. V is N/C the amount of froce that acts on a unit of charge. And the potential difference between two points is also measured in V. This is the voltage you use in Ohm’s law R=U/I, U is the potential difference or voltage R is the resistance and I is the current.

W is just Watt its power, energy/time J/s. If you got a heater and its 500 W power it means it gives heat to water for example at a rate of 500 J/s.

Heating water looks like this Q = c×m×T where Q is the energy c defines how easy it is to warm up the thing m is the mass of the thing and T or usually delta T is the temperature increase we want. So lets go with 0°C->100°C and 1 liter or 1 kg water. c=4200 J/kg°C for water so that means: 4200 × 1 × 100 = 420000 J. We can do 500 J/s so 420000 J / 500 J/s = 840s so 14 minutes. Electroc kettles are around 2000 W that gives about 3 minutes.

Forget the H for now.

Imagine electrons in a wire are like guys in an obstacle course. V for voltage is how much energy each guy has. This is what they use to push through obstacles, maybe jumping over fences (arcing across gaps), pushing through turnstiles (actually making the appliance work), or just slogging through the mud (moving along the wire). I is the current. It’s usually measured in voltage, which is just joules (energy) per coulomb (charge), or energy per guy. A is just a measure of current (I), how many guys go past a checkpoint in a given amount of time. It stands for Amperes, and is just coulomb’s per second (guys per second). W is Watts, and is a unit of power. It’s energy per second, which is really just the number of guys per second times the energy of each guy. It’s how much energy you’re getting from that turnstile they’re pushing through every second.

All that AH is is amp hours. It means how many hours worth of that rate of runners do you have. Then WH is the same, but for the rate of energy (i.e. the current times the voltage). 2000AH means you could run at 1A for 2000 hours or at 2000A for 1 hour, or anything in between! As long as the two numbers multiply to 2000.

V (Volts) – the power bank “V” out and the device “V” in must match. Usually at 5 volts.

A (Ampere) – it is written on both the power bank and the device.

AH (Ampere-hour) – the power bank “AH” means that it can pretty much deliver the “A” written on it for an ‘hour’ at its “V” rating.

Your device battery also have its “AH” rating. Just divide the power bank “AH” by the device’s “AH” rating to get how many times you can charge it.