Let's talk Ah

[bigtwin]

I've had ample info to give me hours of watt if, this, watt if that, but now I'm revolting!

Resistance is futile!

Ian

 

[meanders]

Probably a good job we are only talking DC. Gets a good deal more complex with AC, RMS, phase matching etc.

 

[Minxy]

Resistance is futile!

Ian

Are you positive? I'm feeling rather negative about it but willing to try to be more neutral.

 

[meanders]

Perhaps we should transfer this to one of the comedy threads.

 

[Minxy]

Perhaps we should transfer this to one of the comedy threads.

Lead the way!

^{_{Subscribers  do not see these advertisements}}

 

[B+W vanman]

Just don’t mention the “L” word………

 

[The Wino]

It’s also worth remembering that a 24v 100ah battery stores twice the power of a 12v one, the ultimate expression of power is watts and watts/hour watts = voltsxamps so the battery above is 2400 or 1200 watt hours now by using the wattage of the TV or fridge you can easily see how long you can run a piece of electrical equipment, you can even combine watts at 12v or 240v. But yes we seem obsessed with ah and make life more difficult

Post edited watts to watt hours

Why if you want to make it easy to see if you can run electrical equipment not quote the battery capacity in KWH? I know it's a really easy conversion but it would be more straightforward. I suspect they manufacturers wouldn't like it as it's a really small number and people might feel unimpressed!

 

[68c]

It's the Volts Watt Hertz, it's the Amps Watt kill you.

 

[Whippet93]

I thought an Ah was just the noise I make when I sit down. Or stand up.

The louder the Ah, the more power required to stand up. Sometimes I make another noise when I sit down. I usually look round and say "watt?".

 

[bigtwin]

Are you positive? I'm feeling rather negative about it but willing to try to be more neutral.

That’s it, you’re grounded and I don’t want to hear anymore about it!

Ian

^{_{Subscribers  do not see these advertisements}}

 

[meanders]

It's the Volts Watt Hertz, it's the Amps Watt kill you.

The higher the Hertz the more it Hertz. I can confirm 750v at RF really hurts and leaves a nasty burn as well as throwing you across the shed. Multiple 802's in parallel with 750,0,750 transformer and large paper capacitors providing the bias deliver a real belt when you cut the power to change out a bubble that is about to burst and forget to ground the rail before removing the top cap too quickly.

 

[KNWH]

OK, one for the engineers:
Jools (sic) will be here in a second to tell you watt’s watt.

 

[meanders]

The louder the Ah, the more power required to stand up. Sometimes I make another noise when I sit down. I usually look round and say "watt?".

Perhaps you should have ensured you had bean?

I was told that it's not 'what', its 'pardon'!

 

[meanders]

OK, one for the engineers:
Jools (sic) will be here in a second to tell you watt’s watt.

That's easy peasy. 1 Watt = 1 Joule per second. Lovely SI units.

 

[68c]

Three cats on a table you slowly tilt the table to. Which cat slides of last?

The one with the highest mu..

^{_{Subscribers  do not see these advertisements}}

 

[swemmy666]

the one with the highest coefficient of friction

 

[meanders]

Be careful 68c. Posts like that could cause friction here?

 

[Carpmart]

If you have a "standard' motorhome it will be 12v throughout. We are talking exceptions not the norm.

Assuming that's the case, then generally the bigger the battery, the longer it will run the equipment you have without charging. Moving to Lithium saves a lot of weight and will give you more power for longer but you need a suitable charger and solar controller.

If putting in an extra battery or more, you connect all the + terminals together and all the - terminals together so still delivering 12V but double, treble or more the capacity. However, the batteries all need to be the same size, type and age. I.e buy them and fit at the same time.

Hopefully a little clearer.

Just for clarity, the lithium batteries don’t need to be the same type, capacity or age running in parallel.

 

[BouncyBoatFolk]

Watt are you talking about?

Ian

He's had amp'le time to digest all that now.
Mike.

 

[Raul]

Alessandro Volta will turn in his grave, the way you lot talk about his invention.
Volt is after someone's name.

^{_{Subscribers  do not see these advertisements}}

 

[meanders]

Alessandro Volta will turn in his grave, the way you lot talk about his invention.
Volt is after someone's name.

That's why I always put the unit as V, not v. Ditto it's W not w. and A not a. SI length is m (metre) not M as it's not named after a real person.

 

[Raul]

That's why I always put the unit as V, not v. Ditto it's W not w. and A not a. SI length is m (metre) not M as it's not named after a real person.

And that is how is written in SI Simbole Internationale. Also the capitals are not limited to names,

 

[meanders]

And that is how is written in SI Simbole Internationale. Also the capitals are not limited to names,

True. Multipliers are capitalised where devisors are not. There is only one other exception I can think of which is the litre = L.

 

[Rapido925M]

You'll be kilo'd for that comment about multipliers!

 

[bigtwin]

Just for clarity, the lithium batteries don’t need to be the same type, capacity or age running in parallel.

I was tempted to clarify that point too.

Ian

^{_{Subscribers  do not see these advertisements}}

 

[Minxy]

That’s it, you’re grounded and I don’t want to hear anymore about it!

Ian

But I'm wired for sound

 

[LithiumConvert]

Choosing the Right Size Battery – If you run a fridge (5A), lights (2A), and a heater fan (3A), using 10A per hour, a 100Ah battery will last around 5 hours before hitting 50% capacity.

The words "per hour" as used are confusing, the fridge, lights and fan use 10A (if all on togther) no matter how long they on.
For the words "per hour" to be used correctly the statement should read. - using 10 Ampere Hour per hour.
or, more simply, don't use the words "per hour" as in the TV example.

The calculation is correct ,but, say, they are only left on for 30 minutes, they will still draw 10A from the battery whilst they are on for those 30 minutes +but the battery will only be depleted by 5 Ampere Hour (Ah). 10A x 0.5 hours.

 

[Rapido925M]

Sorry but you are being inconsistent AND wrong
According to your first statement you should have written “10Ah x 0.5h” which would give you 5Ahh.

 

[Steve and Denise]

Steve and Denise Not arrived yet Steve, at local delivery depot so expecting it anytime soon, probably tomorrow! Old fridge is out and think I’ve found a recycling centre to drop it off at… holding off as a local bloke wants to potentially buy it to harvest parts.

Do you recall clearances when you fitted yours Steve? Is the fridge completely flat backed so needs 563mm clearance top to bottom? I’ve got quite a large wiring loom/harness and an Alde pipe run round the back of the fridge space, all low level, but may need some fettling!

Carpmart the back is completely flat and goes back against the wall unlike the old fridge you will have to remove the seal used to separate the gas part of the old fridge as it will stop you pushing it right back to the wall.

 

[Carpmart]

Carpmart the back is completely flat and goes back against the wall unlike the old fridge you will have to remove the seal used to separate the gas part of the old fridge as it will stop you pushing it right back to the wall.

Seals already out Steve… 230 socket removed also… and yes, it looks cleaner and tidier than when I took the picture!

just got cabling and pipes at the bottom back… will have to try it and see… when it arrives!

^{_{Subscribers  do not see these advertisements}}