Question about : Anker 737 Power Bank

#1

Hi guys, I am going to buy (I hope there will be good deal for black friday) Anker 737 Power Bank as title says it have 24000mah, so as I see on picture it says “charge iphone 13 4.9 times”
iphone 13 have 3,227 battery so 3,227*4.9=15812 Mah , So where is that 8187.7 mah? can someone explain me principe of this power bank? Thanks…

#2

So the voltage of your phone’s battery and the cells in the 24K probably aren’t the same voltage so you need to compare to begin with their Watthours as more accurate.

The 737 is 86.4Wh so means 24,000mAh implies (86.4/24) 3.6V.

Your iphone 13’s battery is 11.97Wh , at 3095mAh implies (11.97/3.095) 3.9V.

So their voltages are not the same so you’d make false conclusions comparing their mAh.

The iphone itself loses typically 20% of the energy within itself just recharging it’s own battery. It’s own internal inefficiency. You can spot this via phone getting hot while recharging. You then also lose typically 5% discharging it’s own power. So you lose around 25% shoving power into the iPhone to then discharge, caused by the iphone itself, nothing at related to the Anker product attached.

Anker product itself loses typically 10%-5% of power , not as much loss as the iPhone. The 737 24K is quite inefficient, less efficient than their lower end products, nearer to 10% or more load, while say a lower end 26800 is losing 4-5%>

86.4 / 11.97 = 7.2

Subtract 10% for Anker to discharge, 20% from Iphone to recharge itself, and 5% to use it’s battery.

7.2 * 0.8 * 0.95 * 0.9 = 4.9

So I’d expect around just under 5 recharges.

Voila, what they said. So they’re being honest. Your understanding of chemistry and electronics was just lacking.

Now you understand better, there’s an exceedingly obvious way to get more iphone hours of use from a Powercore, don’t lose 20% simply recharging a flat iphone battery to then recharge losing a further 5%, which you then repeat, just have the powerbank keep your phone charged, so then it’s not 7.2 x 0.8 x 0.95 x 0.9 but 7.2 x 0.9 = 6.5

So you’d get roughly 1.6 times more phone recharge equivalents if the powercore you have with you all the time, just kept it plugged in as you use the iphone.

There’s also another benefit. Your iphone’s battery has roughly 300 recharge cycles built in. So every time you leave that Powercore disconnected while your iphone discharges so burning one of the phone’s recharge 300 cycles. Rather better is you just kept the iphone connected to the Powercore, you use less of those 300 cycles, so your phone’s battery will last longer.

So not only carry a Powercore, keep it connected to your phone, your phone will last years longer and you get more phone time for a given Powercore.

What this means for example is a 20000mAh 10W Powercore will give more phone recharges than this 24K via keeping connected to your phone.

I roll my eyes in wonder as folks keep aiming for larger and more power Powercore and then keep it disconnected from their phone.

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#3

Darn, @professor beat me to the explanation! Of course, I was just going to say “it’s magic”…. So his explanation is probably more along the lines of “helpful”…. :joy::rofl::joy:

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#4

thanks so much!!!

#5

I Just received a new Anker 737 Power Bank (PowerCore 24K) PB and love it so far,… I do have one question though,…

It appears to be discharging itself by about 5% a day when just siting on the shelf with nothing connected. I got it as an emergency backup and for travel and had hoped that it would hold the charge.

My question is: Is this standard (losing ~5% a day), or do I have a bad apple. Or are there settings that I inadvertently have on, that allow it to discharge itself? Any (helpful) thoughts would be appreciated.

Thanks, R

#6

Should be a question for the engineers from ANKER.
Strange indeed!

#7

Lithium ion batteries should not lose power when not in use. If the display is on, it will suck up power. To turn off the power bank, press and hold the button until the display goes blank.

#8

I mentioned that.
Its really not normal.
There is something wrong.

#9

I have one of these and it does not lose power when completely off.