I could work it out myself but there are Boffins here who can do it for me pro bono.

How much mass would I need to lift say 3 metres to have the same amount of energy as a 12v 40 amp hour battery?

Peak Warming Man said:

I could work it out myself but there are Boffins here who can do it for me pro bono.

How much mass would I need to lift say 3 metres to have the same amount of energy as a 12v 40 amp hour battery?

at a guess my 70 kg bucket with 70 kg of opal mullock in it can travel 10 m between click/bang.

Thanks.

roughbarked said:

Peak Warming Man said:

I could work it out myself but there are Boffins here who can do it for me pro bono.

How much mass would I need to lift say 3 metres to have the same amount of energy as a 12v 40 amp hour battery?

at a guess my 70 kg bucket with 70 kg of opal mullock in it can travel 10 m between click/bang.

Sounds like your bucket is over engineered.

roughbarked said:

Peak Warming Man said:

I could work it out myself but there are Boffins here who can do it for me pro bono.

How much mass would I need to lift say 3 metres to have the same amount of energy as a 12v 40 amp hour battery?

at a guess my 70 kg bucket with 70 kg of opal mullock in it can travel 10 m between click/bang.

It uses a lot more than a 12v 40 amp hour battery can put out.. to lift it back up.

Ep = mgh

m = mass
g = acceleration due to gravity
h = height in meters

Skunkworks said:

roughbarked said:

Peak Warming Man said:

I could work it out myself but there are Boffins here who can do it for me pro bono.

How much mass would I need to lift say 3 metres to have the same amount of energy as a 12v 40 amp hour battery?

at a guess my 70 kg bucket with 70 kg of opal mullock in it can travel 10 m between click/bang.

Sounds like your bucket is over engineered.

I haven’t actually weighed it.. just guessing that it is heavy enough without dirt in it..
see picture..

It uses a lot more than a 12v 40 amp hour battery can put out..

that isn’t the energy contained in the battery but what it can supply.

Boris said:

It uses a lot more than a 12v 40 amp hour battery can put out..

that isn’t the energy contained in the battery but what it can supply.

you’d need some awfully big gearing to lift that bucket with a 12 volt motor

you’d need some awfully big gearing to lift that bucket with a 12 volt motor

irrelevant.

Boris said:

you’d need some awfully big gearing to lift that bucket with a 12 volt motor

irrelevant.

I know but it was fun to say it..

12 volt winches can be geared to pull 4000kg. ask a fwdriver.

i think the question is worded wrong though. you need the capacity of the battery. 40 amps for how long?

yes a mouse can with gearing climb 3 m and make a lot of amps

Peak Warming Man said:

I could work it out myself but there are Boffins here who can do it for me pro bono.

How much mass would I need to lift say 3 metres to have the same amount of energy as a 12v 40 amp hour battery?

1 joule = 1 watt = 1V *1A for 1 second

or in passing an electric current of one ampere through a resistance of one ohm for one second.
http://en.wikipedia.org/wiki/Joule
(wookie note 1V = 1A *1 ohm P = 1V *1A

PE = mass * gravity * height

convert your total energy into joules for the battery that it can output per second in practical terms
then compare the amount of mass at 3m high you’d need to make it the equivalent joules/second

12V at 40 A for one second would be 480J

PE = m g h

480 = m * 10 * 3

480/3 = m

m = mass needed to have the same PE as energy provided by the battey for 1 second

thats how i see it but i’m tired
if anyone wants to correct me feel free

wookiemeister said:

Peak Warming Man said:

I could work it out myself but there are Boffins here who can do it for me pro bono.

How much mass would I need to lift say 3 metres to have the same amount of energy as a 12v 40 amp hour battery?

1 joule = 1 watt = 1V *1A for 1 second

or in passing an electric current of one ampere through a resistance of one ohm for one second.
http://en.wikipedia.org/wiki/Joule
(wookie note 1V = 1A *1 ohm P = 1V *1A

PE = mass * gravity * height

convert your total energy into joules for the battery that it can output per second in practical terms
then compare the amount of mass at 3m high you’d need to make it the equivalent joules/second

12V at 40 A for one second would be 480J

PE = m g h

480 = m * 10 * 3

480/3 = m

m = mass needed to have the same PE as energy provided by the battey for 1 second

thats how i see it but i’m tired
if anyone wants to correct me feel free

480/30 = m

wookiemeister said:

Peak Warming Man said:

I could work it out myself but there are Boffins here who can do it for me pro bono.

How much mass would I need to lift say 3 metres to have the same amount of energy as a 12v 40 amp hour battery?

1 joule = 1 watt = 1V *1A for 1 second

or in passing an electric current of one ampere through a resistance of one ohm for one second.
http://en.wikipedia.org/wiki/Joule
(wookie note 1V = 1A *1 ohm P = 1V *1A

PE = mass * gravity * height

convert your total energy into joules for the battery that it can output per second in practical terms
then compare the amount of mass at 3m high you’d need to make it the equivalent joules/second

12V at 40 A for one second would be 480J

PE = m g h

480 = m * 10 * 3

480/3 = m

m = mass needed to have the same PE as energy provided by the battey for 1 second

thats how i see it but i’m tired
if anyone wants to correct me feel free

480/30 = m

i’ll take my last post back after rereading the op. sorry pwm.

Thanks Wookie.

Peak Warming Man said:

Thanks Wookie.

you could think of a hammer coming down and striking a metal plate as well

if the hammer is dropped from a height with a mass it will strike the plate

the PE of the hammer could be converted into KE as it falls BUT either way assuming no losses the metal plate will have be given X amount of energy

Q = M C delta T

energy given to the plate from the plate = mass of metal plate * specific heat capacity of metal * change in temp of plate

yep. Thanks wookie.

In some ways the question is ill defined, as the energy that a battery can produce depends upon the time it takes. As a quick example, and looking at the spec sheet for a fairly standard 12 volt 40 amp/hour battery, at the 30 minute discharge rate the battery will produce approximately 6.84 × 10^4 Joules.

If the time spent dragging energy from the battery was increased to 10 hours then the amount of energy produced goes up to 1.3 × 10^5 Joules.

So about 1.9 times more energy is produced under the slower discharge rate.

Wookie’s calculation is for one second of battery output.

If the battery could keep up 40 amps for an hour, you could lift an amazing 5.88 tonnes a height of 3 metres.

Recovering the energy poses some issues though.

In some ways the question is ill defined,

i take back my take back. and the apology.

what are you trying to do?

as someone has intimated the output of the battery can vary

point of interest

cell versus battery

a cell is the basic construct to provide electrical power , more than one of them constitutes a battery
you could say “can you give me a AA 1.5 V cell please” but you couldn’t say “can you give me a AA 1.5 V battery please”

eg a battery hen, an artillery battery

a cell/ battery has internal resistance
1V = 1A * 1 ohm V = IR

POI
V = IR is not quite the full story
V is proportional to I
as V increases so does I
it is implied that another constant is in play – in this case R (ohms)
so V = I K (konstant) R is the konstant
so V = I R

getting back to the cell/battery

when you start to draw large amounts of current from the battery/ cell you have to remember that the current must also travel through the cell/ battery itself – and does work on itself, the battery/cell starts to get HOT and the internal resistance INCREASES and restricts the current flowing.

sibeen said:

In some ways the question is ill defined, as the energy that a battery can produce depends upon the time it takes. As a quick example, and looking at the spec sheet for a fairly standard 12 volt 40 amp/hour battery, at the 30 minute discharge rate the battery will produce approximately 6.84 × 10^4 Joules.

If the time spent dragging energy from the battery was increased to 10 hours then the amount of energy produced goes up to 1.3 × 10^5 Joules.

So about 1.9 times more energy is produced under the slower discharge rate.

yes.

definition is everything in asking a question but at the same time if we could define it, we may find we no longer need to ask the question.

in essence when you try to do large amounts of work using a battery the increase of internal resistance means that WORK ends up being done on the battery and makes it less efficient.

By way of a cross check, my 300 watt solar pump lifts 15 tonnes of water 15m over about 5 hours in summer. It is surprising how much water you can lift with a small power source.

Of course there is another urgent issue that should be raised.

What do you mean by a 40 amp/hour battery?

I know of at least 5 different ways that the 40 amp figure is arrived at, none of which agree with each other.

Please redefine the question, or move along.

you would be better off using a generator to provide power than a battery bank if you are thinking of trying to shift dirt in big quantities

morrie said:

By way of a cross check, my 300 watt solar pump lifts 15 tonnes of water 15m over about 5 hours in summer. It is surprising how much water you can lift with a small power source.

wow

sibeen, giving Boris get outs since 2004!

is cold cranking power legit or is it like pmpo is to audio amps?

Legit. Not something that I’ve ever worked with, but in automotive applications the CCA is the biggie.

40 amp hour

40Ah = 3600 * Amps

http://en.wikipedia.org/wiki/Ampere-hour

or you could have

40Ah = 1 second * 40A assuming the battery was amazing

wookiemeister said:

40 amp hour

40Ah = 3600 * Amps

http://en.wikipedia.org/wiki/Ampere-hour

or you could have

40Ah = 1 second * 40A assuming the battery was amazing

or not because we are talking about hours not seconds??

you could say 1 second is 1/3600 of an amp hour i guess

wookiemeister said:

you would be better off using a generator to provide power than a battery bank if you are thinking of trying to shift dirt in big quantities

that’s exactly what I do.. which is where I came in.

Wookie, battery manufacturers lie, cheat, steal, do anything possible to get their battery a better ranking – ie -amp/hour capacity.

40 A/hr means that a battery should be able to produce 40 amps for 1 hour. This used to be – long, long, long ago a reasonable definition. As batteries are a chemical device, they will produce more energy the longer the discharge period, as the chemical reaction is more effecient.

So, some ‘smart’ manufacturer realised that my battery can’t produce 40 amps for 1 hour, but it can produce 13 amps for 3 hours. So we’ll call that a 40 amp/hour battery – at the 3 hour rate.

This then moved to 5 amps for 8 hours, and then 4 amps for 10 hours, and then 2 amps for 20 hours.

For a while there it did seem that most manufacturers were going to stop at the 10 hour rate and begin a de facto standard, but unfortunately not. A hell of a lot of batteries are now specified at the 20 hour rate.

Of course, taking the OP at face value where it states “to have the same amount of energy as a 12v 40 amp hour battery” could also mean that we take the weight of the battery into play and use a fairly famous equation and find that the amount of energy produced by this battery is in the order of 1.144 × 10^18 Joules, which is quite a bit.

sibeen said:

Of course, taking the OP at face value where it states “to have the same amount of energy as a 12v 40 amp hour battery” could also mean that we take the weight of the battery into play and use a fairly famous equation and find that the amount of energy produced by this battery is in the order of 1.144 × 10^18 Joules, which is quite a bit.

Yep.. The same result would occur if I was standing under either my bucket full of dirt going the wrong way or the battery coming down.. I’d be dead.. As many would obviously wish me.

sibeen said:

Wookie, battery manufacturers lie, cheat, steal, do anything possible to get their battery a better ranking – ie -amp/hour capacity.

40 A/hr means that a battery should be able to produce 40 amps for 1 hour. This used to be – long, long, long ago a reasonable definition. As batteries are a chemical device, they will produce more energy the longer the discharge period, as the chemical reaction is more effecient.

So, some ‘smart’ manufacturer realised that my battery can’t produce 40 amps for 1 hour, but it can produce 13 amps for 3 hours. So we’ll call that a 40 amp/hour battery – at the 3 hour rate.

This then moved to 5 amps for 8 hours, and then 4 amps for 10 hours, and then 2 amps for 20 hours.

For a while there it did seem that most manufacturers were going to stop at the 10 hour rate and begin a de facto standard, but unfortunately not. A hell of a lot of batteries are now specified at the 20 hour rate.

lie , cheat even kill!

wookiemeister said:

sibeen said:

Wookie, battery manufacturers lie, cheat, steal, do anything possible to get their battery a better ranking – ie -amp/hour capacity.

40 A/hr means that a battery should be able to produce 40 amps for 1 hour. This used to be – long, long, long ago a reasonable definition. As batteries are a chemical device, they will produce more energy the longer the discharge period, as the chemical reaction is more effecient.

So, some ‘smart’ manufacturer realised that my battery can’t produce 40 amps for 1 hour, but it can produce 13 amps for 3 hours. So we’ll call that a 40 amp/hour battery – at the 3 hour rate.

This then moved to 5 amps for 8 hours, and then 4 amps for 10 hours, and then 2 amps for 20 hours.

For a while there it did seem that most manufacturers were going to stop at the 10 hour rate and begin a de facto standard, but unfortunately not. A hell of a lot of batteries are now specified at the 20 hour rate.

lie , cheat even kill!

Yeak.. the latter too.

Um as an aside.. I currently have a problem of that type.. I returned my oxy-acetylene bottles when they sent me a bill for rent or as they put it, container service. On the back of the bill it says select 12* container service is charged12 months in advance for a fixed term.

OK so if I retuned the bottles .. what service are they charging me for?

roughbarked said:

wookiemeister said:

sibeen said:

Wookie, battery manufacturers lie, cheat, steal, do anything possible to get their battery a better ranking – ie -amp/hour capacity.

40 A/hr means that a battery should be able to produce 40 amps for 1 hour. This used to be – long, long, long ago a reasonable definition. As batteries are a chemical device, they will produce more energy the longer the discharge period, as the chemical reaction is more effecient.

So, some ‘smart’ manufacturer realised that my battery can’t produce 40 amps for 1 hour, but it can produce 13 amps for 3 hours. So we’ll call that a 40 amp/hour battery – at the 3 hour rate.

This then moved to 5 amps for 8 hours, and then 4 amps for 10 hours, and then 2 amps for 20 hours.

For a while there it did seem that most manufacturers were going to stop at the 10 hour rate and begin a de facto standard, but unfortunately not. A hell of a lot of batteries are now specified at the 20 hour rate.

lie , cheat even kill!

Yeak.. the latter too.

Um as an aside.. I currently have a problem of that type.. I returned my oxy-acetylene bottles when they sent me a bill for rent or as they put it, container service. On the back of the bill it says select 12* container service is charged12 months in advance for a fixed term.

OK so if I retuned the bottles .. what service are they charging me for?

hookers

wookiemeister said:

roughbarked said:

wookiemeister said:

lie , cheat even kill!

Yeak.. the latter too.

Um as an aside.. I currently have a problem of that type.. I returned my oxy-acetylene bottles when they sent me a bill for rent or as they put it, container service. On the back of the bill it says select 12* container service is charged12 months in advance for a fixed term.

OK so if I retuned the bottles .. what service are they charging me for?

hookers

thought so.

missus freaked out.. I said.. nah.. wait until they send the debt collectors to waste their money looking.

Google to the rescue

(((12 V) * 40 (A hours)) / (9.8 (m / (s^2)))) / (3 m) = 58 775.5102 kilograms

Um as an aside.. I currently have a problem of that type.. I returned my oxy-acetylene bottles when they sent me a bill for rent or as they put it, container service. On the back of the bill it says select 12* container service is charged12 months in advance for a fixed term.

OK so if I retuned the bottles .. what service are they charging me for?
—-

Like they said: they are charging you for the rental of the equipment, same as hiring any piece of equipment.

dv said:

Um as an aside.. I currently have a problem of that type.. I returned my oxy-acetylene bottles when they sent me a bill for rent or as they put it, container service. On the back of the bill it says select 12* container service is charged12 months in advance for a fixed term.

OK so if I retuned the bottles .. what service are they charging me for?
—-

Like they said: they are charging you for the rental of the equipment, same as hiring any piece of equipment.

and as I said.. the rental is in advance.. so if anything I only owe them for whatever days the bottles were returned when I got the bill.. it isn’t my fault the post is slow out here.. ;)

>>Google to the rescue
(((12 V) * 40 (A hours)) / (9.8 (m / (s^2)))) / (3 m) = 58 775.5102 kilograms

58 tonnes!!!! FMD, no wonder they don’t use potential energy as a storage device except in hydro.

Hmm,

(12 V) * 40 (A hours) = 1,728,000 Joules, according to google.

This is about 13 times the amount of energy that I calculated a battery can provide.

At a height of 3 metres I get 4400 kg.

Actaully, 12 volts x 40 A*hr does equal 1,728,000 Joules, it’s just that batteries don’t work like that.

My figure will be way closer to the mark – approximately 4 tonnes.

sibeen said:

Actaully, 12 volts x 40 A*hr does equal 1,728,000 Joules, it’s just that batteries don’t work like that.

My figure will be way closer to the mark – approximately 4 tonnes.

still a lot bigger than my bucket of mullock.

DV “ >>Google to the rescue (((12 V) * 40 (A hours)) / (9.8 (m / (s^2)))) / (3 m) = 58 775.5102 kilograms”

sibeen “(12 V) * 40 (A hours) = 1,728,000 Joules, according to google. This is about 13 times the amount of energy that I calculated a battery can provide. At a height of 3 metres I get 4400 kg.”
——————-

How did you get that, sibeen?

How did you get that, sibeen?

obtuse irish notation.

DV, from a typical battery battery specification.

cough

OK, I stuffed up. I read the constant current data and not the constant wattage and so, perhaps, just perhaps, put the wrong data into my calculation.

I was drunk, I tells ya.

I now get 50.3 tonnes.

The battery can provide 1.48 × 10^6 Joules, using the 10 hour discharge rate, this gives 1.5 × 10^5 m*kg, so at 3 metres about 50 tonne.

>obtuse irish notation.

Yes sheepish look err, maybe. I blame the stout!

assuming no losses

http://www.youtube.com/watch?v=v3pYRn5j7oI

richard feynman mentions the hammer hitting something and causing heating or jiggling of the atoms (that i mentioned earlier)

i especially liked the youtube feynman lectures on lock picking and break and entry for newbies