There are no forum members that confuse A and AH.

[Fuss]

We have this endless point that some of us don't know the difference between Amps and Amp Hours. It consumes many pages of many threads.



How can that be... its nearly impossible right... at worst its a spelling mistake or bad sentence structure trying to express a point.


Everyone on here has a battery monitor of some sort and every battery monitor shows Amps and consumed amps by way of AH.


Now this then makes it impossible to not know the difference.


Now, I know what some of you are thinking...no its not true, not everyone has a battery monitor ... but lets not go there.


I bet there is no-one on here that does not know the difference, even if you didn't you would just have to look at the numbers on the A screen and on the AH screen and all would be clear.


If they didn't have one , then they would not ever post about A or AH.

[JoeRobertJr]

Yes, the difference is importance. Many sailors are not electrical engineers. Those of us who are can courteously help them understand the difference and the implications. It does not help someone trying to learn by responding with criticisms like "You clearly don't know what you are doing. Hire a marine certified electrician before you burn down your boat." I see that as often as I see A vs. AH confusion.

By the way, I don't have a battery monitor, other than a voltmeter.

[boatman61]

A voltmeter..
AH.. it works..!!!

[team karst]

Should not capitalize the “h”. [emoji41]

[steve77]

Originally Posted by team karst

Should not capitalize the “h”. [emoji41]

Further to this point, the way it was explained to me is that units named after people should be capitalized. This includes Volts, Amperes, Watts, Coulombs, etc. Units such as hour, second, gallon, etc. are not capitalized.

Cheers!

Steve

[Chotu]

For better of for worse, conversationally, humans are trending away from strict formalities.

Being required to leave a “.” off every text and tying to make conversations short to the point of miscommunication is very trying for me but is the trend

[s/v Jedi]

It’s A, V, W because these units are named after their inventors.

So it’s Ah, kWh, VA etc.

You cannot consume Amps but you can consume Ah’s.

It’s time to step away from Ah as a unit for energy generation and storage because it isn’t a measure of energy at all. Your solar panels generated 3.2kWh yesterday and your batteries can store 6.3kWh. Those are the correct units to use and they work for any system voltage.

[SV THIRD DAY]

Science has shown that posting a corrective post online releases endorphins in the poster similar to those released during sex. Once you understand that…so much of the online works begins to make sense.

[Chotu]

Originally Posted by s/v Jedi

It’s time to step away from Ah as a unit for energy generation and storage because it isn’t a measure of energy at all. Your solar panels generated 3.2kWh yesterday and your batteries can store 6.3kWh. Those are the correct units to use and they work for any system voltage.

Strongly agree! Especially since systems run at different Voltages. It’s not very precise.

The kWh is the definitive unit and should be standard so we can all compare apples to Apples.

It would also be nice to be able to think in terms of energy in general with one unit. Heating, air conditioning, stored energy, energy production, engine/motor output, etc. They could all be conceptually so much easier to compare with a single unit.

[noelex 77]

Ahrs is still a useful unit on a boat. Batteries do not store Whrs.

Near the end of the charge cycle when the voltage is higher, batteries are not storing more energy because of this higher voltage. AHrs into the battery more accurately corresponds to the Ahrs that can be withdrawn from the battery than doing the same calculation with Whrs.

Whrs are the official unit for electrical energy and this unit is particularly appropriate when discussing mixed voltages, but Ahrs is still a better unit when dealing with energy storage in batteries. This is why most battery monitors report Ahrs not Whrs.

I think both units can be used to good effect depending on the situation.

[thomm225]

Originally Posted by Fuss

We have this endless point that some of us don't know the difference between Amps and Amp Hours. It consumes many pages of many threads.

How can that be... its nearly impossible right... at worst its a spelling mistake or bad sentence structure trying to express a point.

Everyone on here has a battery monitor of some sort and every battery monitor shows Amps and consumed amps by way of AH.

Now this then makes it impossible to not know the difference.

Now, I know what some of you are thinking...no its not true, not everyone has a battery monitor ... but lets not go there.

I bet there is no-one on here that does not know the difference, even if you didn't you would just have to look at the numbers on the A screen and on the AH screen and all would be clear.

If they didn't have one , then they would not ever post about A or AH.

Actually my Battery Monitor doesn't give any information on Amps vs Amp Hours, but I really don't need that information anyway.

I just need to know how much battery power I have left which my Altus Gauge does very well ........ That is after you tap on it a bit to get the correct reading.

[JBP]

Originally Posted by Fuss

How can that be... its nearly impossible right... at worst its a spelling mistake or bad sentence structure trying to express a point.

1) Another reason is that some people are unable to sail at the moment and are surfing the web for something to talk about, even if it is bickering about typos.

2) "Ahrs is still a useful unit on a boat. Batteries do not store Whrs."
Of course they do. Watt hours is just another way of denoting stored potential. In fact some people don't have 12 Volt systems so Watt hours is more definitive (see point 1!)

[Baronkrak]

Originally Posted by s/v Jedi

It’s A, V, W because these units are named after their inventors.

So it’s Ah, kWh, VA etc.

You cannot consume Amps but you can consume Ah’s.

It’s time to step away from Ah as a unit for energy generation and storage because it isn’t a measure of energy at all. Your solar panels generated 3.2kWh yesterday and your batteries can store 6.3kWh. Those are the correct units to use and they work for any system voltage.

In any case VA should be used for direct current.
Not to worry, even Victron uses incorrectly W for VA. (BMV 712)
Beginner common mistake.

[Jammer]

Coulombs are the preferred unit of charge, we should use those instead of Ah as they are much less confusing. For example the AGM batteries on my boat are about 400,000 Coulombs or 400 kC. Though some people may confuse this with the 400 kHz aeronautical beacon frequency since the term 'kilocycles' was once in widespread use but properly abbreviated kc instead of kC.


Similarly we ought to be talking about Joules rather than kWh. So much clearer.

Originally Posted by noelex 77

Ahrs is still a useful unit on a boat. Batteries do not store Whrs.

In battery technology circles, the concepts of "Coulombic capacity," e.g. Ah, and "Energy capacity," e.g. Wh, are both used depending on what is being discussed.

[rslifkin]

Originally Posted by Baronkrak

In any case VA should be used for direct current.
Not to worry, even Victron uses incorrectly W for VA. (BMV 712)
Beginner common mistake.

In the world of DC power I don't know of any situation where watts doesn't equal VA. AC power is a different story though.