energy monitor favour please

ariarnia

can someone with an energy monitor and smart phone please settle a question for us. 

can you please run your phone until it turns itself off then plug it in to charge and tell us how much energy it actually uses for the battery to be full again please? 

thank you. 

BUFF

mobile phone batteries vary in capacity quite substantially.

ariarnia

yes but if we know which mobile phone it is then it'll still settle the argument because we can look up the stated capacity and compare it to the findings. its not about exact figures for a specific phone so much as the exact figures for a phone. if more than one person wants to do it and share their numbers then that's even better. ideally several people will do it every day for a week but i thought that was maybe asking to much for a favour

Spoonie_Turtle

I would but our energy monitor only goes to 2 decimal places for the total used, which for something that small probably won't be accurate enough.   [Edit: I probably will at some point anywayout of my own curiosity, but obviously can't commit to it being accurate enough to settle a debate.]

My wheelchair battery (which is at the smaller end of wheelchair batteries, to be fair) used just 0.18kWh from almost flat, and that was including a refresh cycle rather than a straightforward recharge.

[Deleted User]

What’s the argument OP?

[Deleted User]

ariarnia said:

yes but if we know which mobile phone it is then it'll still settle the argument because we can look up the stated capacity and compare it to the findings. its not about exact figures for a specific phone so much as the exact figures for a phone. if more than one person wants to do it and share their numbers then that's even better. ideally several people will do it every day for a week but i thought that was maybe asking to much for a favour

It is not as simple as you suggest. Batteries degrade over time: that is, the battery capacity reduces. Without knowing the exact phone model, you are asking the impossible. FWIW, I have an IPhone 13. The IPhone 13 has a Pro version with a higher capacity battery. My wife has an IPhone SE2 which takes a lot less time to charge as it has a smaller battery. The corollary to this is that my wife has to charge her phone more often than I do mine.

You could buy an energy monitor: however, not all energy monitors are good at showing very small power loads.

Treat all Press estimates with a high degree of scepticism but here is one to be going along with:

An iPhone 12 Pro Max will cost £3.14 per year to keep charged - that's less than 1p per day and just 26p per month.

The phone uses a 20 watt charger and takes two hours and 27 minutes to get a full battery.

Uswitch used a rate of 17.2p per kilowatt hour to calculate the amount.

(You will need to recalculate the cost based on your new unit price )

Glum

You could break into the DC charging cable and insert a multimeter to measure the current. That would give a very accurate value but it's such a negligible amount of power it's hardly worth the hassle.

On a global scale? Huge!

ariarnia

Deleted_User said:

What’s the argument OP?

not an 'argument' really. more like the question of if there's more wheels or doors in the world. i'm not sure there's a right answer but it should be possible to get a ballpark upper and llower range. 

we're thinking about the cost of charging phones at work or on the train and how many times you could charge a phone for a kw of electric. individually tiny amounts but if you had 6000 members of staff charging personal devices every working day then it might be a noticeable line item in an audit.

then that leads to the question of how much a phone actually costs to charge from flat.  if flat is 'flat'. charge vs published battery capacity. and if that's pro rata from 0 to full as if it's at 40 percent topped up to the low battery mode being turned off at 80. (like the figure quoted above and in other places. it's got a 20w charger but is it actually drawing 20w for the whole time given battery optimisation and is it charging the full battery capacity) and a small question i have of if theres a difference between plugging in or wireless charging for the more recent models when it comes to loss. 

it's been ongoing for a few months but we recently travelled on the train to london and back which sparked it off again. i've been truing to use our power bank to work out some of the info but the numbers from that really aren't helpful other than setting an upper limit because of course there's losses at each stage. ideally like i said we'd have several people charging different phones repeatedly but that seems a bit unlikely

ariarnia

Dolor said:

An iPhone 12 Pro Max will cost £3.14 per year to keep charged - that's less than 1p per day and just 26p per month.

The phone uses a 20 watt charger and takes two hours and 27 minutes to get a full battery.

Uswitch used a rate of 17.2p per kilowatt hour to calculate the amount.

(You will need to recalculate the cost based on your new unit price )

yes those are the types of examples we've been talking about but that's why i wondered if we could do a real world test or tests because there are lots of different things that might been those figures are out by a long way.

[Deleted User]

Would this help?  It’s not quite the data you want, but it’s a study I’ve reviewed before and think the data is reasonably accurate.

Across a battery charging cycle, both current and voltage change depending on the cell conditions.  The voltage is much more stable than the current.

You can see the current changes on the graph, where the slope starts to change at about 85% - that’s the current decreasing, and it’s also why a phone gets to 85% fast and then takes ages to get to 100%.

ariarnia

awesome. but i'm not sure how to read that... little bear brain again. can you give an example of how to work out one. like the honor 9 lite charging from 15 to 100 takes to my eye 1.25 hours.

1 amp is 120 watts so is that then saying it's using 150 watts? i'm not sure if the 5V means 5 volts or if it's part of the model because not all of them have a number for V. if it's 5 volts and 1 amp then that's 5 watts an hour, yes?

as you might guess a big part of the problem with this discussion is my math skills just not being up to scratch for the detail we're talking about