What are watt hours? I have heard this term before but don't know what it means?
What Are Watt Hours?
- Thread starter williamclarkonet
- Start date
- th_trl_thread_readers 0
- Status
It's amount of electrical energy. It's what is in your electricity bill (OK, not W/hour but kilowatt/ hour).
If you have a coil, set it to be heated at 1 W and heat it for 1 hour you'll spend 1 W/hour energy. If you have electrical stove with burner of 1 kW (usual thing) and will prepare your food on it for 1 hour, you'll spend 1 kW/h energy (or about 12 cents worth of electricity).
If you wish you can convert mAh to W/h (but what for?):
Wh = mAh × V / 1000 (V - voltage).
If you have a coil, set it to be heated at 1 W and heat it for 1 hour you'll spend 1 W/hour energy. If you have electrical stove with burner of 1 kW (usual thing) and will prepare your food on it for 1 hour, you'll spend 1 kW/h energy (or about 12 cents worth of electricity).
If you wish you can convert mAh to W/h (but what for?):
Wh = mAh × V / 1000 (V - voltage).
alien Traveler" data-source="post: 18221919" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch">Thanks so much for the info! i have another question someone told be with a series mod you dont get double the mah but he said you get more watt hours what was he talking about?alien Traveler said:
Series: (-) -[[[4.2v[}+ -[[[4.2v[}+ (+) gives output up to 8.4v and for demonstration, we will say it takes 1 hour to discharge your batteries through use.
Parallel: -[[[4.2v[}+
(-)-[[[4.2v[}+ (+) gives output 4.2v for 2 hours for the sake of demonstration.
Sorry, this isn't great for artwork but in series, you have - to + to - to + and parallel you have -- to ++ which requires a conductive plate.
Here is an example you can google. An Istick 100w takes 2 batteries in parallel, and gives aprox 5v output. An IJOY 200w, using the same 2 batteries in series gives 10v output, but drains twice as fast. So we can see each battery gives 100w per 5v. One drains slower at lower power, one drains faster but at double the power output.
Parallel: -[[[4.2v[}+
(-)-[[[4.2v[}+ (+) gives output 4.2v for 2 hours for the sake of demonstration.
Sorry, this isn't great for artwork but in series, you have - to + to - to + and parallel you have -- to ++ which requires a conductive plate.
Here is an example you can google. An Istick 100w takes 2 batteries in parallel, and gives aprox 5v output. An IJOY 200w, using the same 2 batteries in series gives 10v output, but drains twice as fast. So we can see each battery gives 100w per 5v. One drains slower at lower power, one drains faster but at double the power output.
With batteries in series the voltage is added. So, eg, two 18650s in series, fresh off the charger, would provide a voltage of 8.4 VDC. They need to be the same mAh rating, since they will both be trying to provide the same current.
My nerdery is unparalleled. LOL.
For safety sake, when talking about a device that can blow your lips off, we will say yes. Do what your device tells you.
Scientifically.. we can say no. Since 3 batteries, 2 in series and 1 in parallel at 4.2v each would give 6.1v for twice as long at 3 in series at 12.6. Hope the math comes out, i just woke up and am doing it in my head on the fly. LOL
For safety sake, when talking about a device that can blow your lips off, we will say yes. Do what your device tells you.
Scientifically.. we can say no. Since 3 batteries, 2 in series and 1 in parallel at 4.2v each would give 6.1v for twice as long at 3 in series at 12.6. Hope the math comes out, i just woke up and am doing it in my head on the fly. LOL
OK...
To put this all in layman's terms.... The math looks like this:
Voltage multiplied by milliamp hours (mAh) divided by 1000 = Watt Hours
V * mAh / 1000 = WH
For series, multiply the voltage by the number of batteries.
For parallel, multipy the mAh by the number of batteries.
So, if we have 2 batteries with a nominal voltage of 3.7V and 3000mAh we have:
Series = (2*3.7) * 3000 / 1000 = 22.2WH
Parallel = 3.7 * (2*3000) / 1000 = 22.2WH
In theory using two batteries in either series or parallel results in the same number of Watt Hours.
However, Series is slightly more efficient than parallel. How much more efficient varies from mod to mod, but series is virtually always more efficient. (It's possible to make a less efficient series mod, but you would have to deliberately try to do it) So, using identical batteries a series mod will always last slightly longer than parallel if all other conditions are identical.
To put this all in layman's terms.... The math looks like this:
Voltage multiplied by milliamp hours (mAh) divided by 1000 = Watt Hours
V * mAh / 1000 = WH
For series, multiply the voltage by the number of batteries.
For parallel, multipy the mAh by the number of batteries.
So, if we have 2 batteries with a nominal voltage of 3.7V and 3000mAh we have:
Series = (2*3.7) * 3000 / 1000 = 22.2WH
Parallel = 3.7 * (2*3000) / 1000 = 22.2WH
In theory using two batteries in either series or parallel results in the same number of Watt Hours.
However, Series is slightly more efficient than parallel. How much more efficient varies from mod to mod, but series is virtually always more efficient. (It's possible to make a less efficient series mod, but you would have to deliberately try to do it) So, using identical batteries a series mod will always last slightly longer than parallel if all other conditions are identical.
It depends on the purpose of the mod though. Istick and IJOY use the same batteries, one in series, one in parallel. Istick uses parallel.. 100w power carried by 2 batteries, so each takes half the load. (read they heat up slower) IJOY used the 2 in series to pump out higher watts, 200w vs 100w. So double the batteries = twice the current. Say 5v per 100w.
Now you can actually use 1 battery in the 100w istick, but you would only get half the usage time as you do using 2.
Nitpick: Wh is a watt-hour which is a real thing. W/h would be watts per hour which, since watts are a rate already and not a quantity, doesn't even make sense. Just like how we use mAh and not mA/h for milliamp-hours.
Semantics aside, though, good answer.
A watt-hour is also equal to 3600 joules, as one joule is equal to a watt-second, and a rate of one J/s (joule per second) is the same thing as a watt.
Last edited:
I would not pay much attention to watts/h for regulated mods. If you put the same (lower) wattage
You are 100% right. Even 150%, in the last sentence.
No, it doesn't depend on the purpose.
Watts is different from Watt Hours. How many watts your mod runs at has nothing to do with hour many Watt Hours the batteries inside provide. The Watt Hours is a measurement of battery charge, nothing more.
Watts is really a meaningless term when talking about mods. A 100W mod cannot run at 100W under all conditions. Watts is part of Ohms Law and is based off the voltage output of the batteries and resistance of the coil. For example, your Istick 100W is incapable of hitting 100W with any coil over 1ohm because of it's voltage limit. So saying "this mod hits 100W because it's parallel and this mod hits 200W because it's series" is just plain false. Neither mod can hit even 100W with a 3ohm coil installed. The voltage requirement is too high for either of them. 100W or 200W is just an artificial cap.
So series or parallel has NOTHING to do with how many watts your mod can hit. The real difference between them is efficiency. In regulated mods series is preferred by manufacturers because it's easier and cheaper to buck the voltage than it is to boost it. You can take two batteries in series pushing out 7V and buck it down to 4V easier and cheaper than you can boost a 4V battery up and output 7V. It's more efficient to use less voltage than your battery outputs than it is to draw more volts than your battery outputs.
Last edited:
2 batteries in series double the volts, amperage stays the same.
2 batteries in parallel, voltage stays the same, amperage doubles.
Your house is wired in parallel so all electrical devices receive the same voltage.
2 batteries in parallel, voltage stays the same, amperage doubles.
Your house is wired in parallel so all electrical devices receive the same voltage.
- Status
Similar threads
- Locked
