500,000mah Power Bank, even though it's much less than expected...... so the question is.....

MarkIpswich · 4 Jul 2020 at 20:30

Feel free to move if this is in the wrong section.

I brought one of these recently,

https://www.ebay.co.uk/itm/500000mAh-Power-Bank-Backup-LED-Portable-Battery-Charger-For-All-Moblie-Phone/174045226129?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649

however the % goes down much quicker than expected. I haven't looked at the batteries yet but is there anyway I can make it 500,000mah (if they really and truly are) using one of those battery holders?

Minstadave · 4 Jul 2020 at 20:34

That rating is just make believe. Looks to be about the size of most 20,000mah packs.

500,000mah would be about 140 18650 cells and weigh 7kg.

Rroff · 4 Jul 2020 at 20:38

Minstadave said:
That rating is just make believe. Looks to be about the size of most 20,000mah packs.

Yup in that form factor won't be much more than about 20,000mah if it is a good product or a little more if using expensive cells.

At £12 I'd be surprised if its much over 5000 real capacity let alone 500000.

Without some electronics experience modifying li-ion charging is not a trivial task.

brendy · 4 Jul 2020 at 20:40

MarkIpswich said:
Feel free to move if this is in the wrong section.

I brought one of these recently,

https://www.ebay.co.uk/itm/500000mAh-Power-Bank-Backup-LED-Portable-Battery-Charger-For-All-Moblie-Phone/174045226129?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649

however the % goes down much quicker than expected. I haven't looked at the batteries yet but is there anyway I can make it 500,000mah (if they really and truly are) using one of those battery holders?

Its probably more like 8ah, I've disected similar from ebay before and the cell was stamped with the true figure.
(Btw bought, not brought, I see this mistake so often on English forums, no idea why its misused so often).

MarkIpswich · 4 Jul 2020 at 20:42

Rroff said:
Yup in that form factor won't be much more than about 20,000mah if it is a good product or a little more if using expensive cells.

At £12 I'd be surprised if its much over 5000 real capacity let alone 500000.

Without some electronics experience modifying li-ion charging is not a trivial task.

Got any sites where I can find the instructions on how?

I'll be using it via Raspberry PI 3 Model B+ with output of 2.5a, though it does require a minimum of 2.0 I do believe.

Minstadave · 4 Jul 2020 at 20:44

MarkIpswich said:
Got any sites where I can find the instructions on how?

To get 500,000mah? Not going to happen. As I said, it'd weigh 7kg plus, need over a hundred cells and be more volume than a car battery.

This is what a real 50,000 MAH battery back looks like:

http://www.maxoak.net/index.php/show-10-22.html

That's a 10th of the capacity of what yours is marketed as and weighs 1.25kg.

You could remove the junk cells from the one you've got and replace them and maybe get 20 to 30,000mah but it'd cost far more than just buying a decent battery pack.

Have a look at this:

https://www.phonearena.com/news/Fak...hy-you-should-buy-genuine-accessories_id78146

MarkIpswich · 4 Jul 2020 at 20:56

I did look for some 20,000 / 30,000mah lithium batteries but unable to find any.

Do you know where there are some available to buy?

Minstadave · 4 Jul 2020 at 21:20

MarkIpswich said:
I did look for some 20,000 / 30,000mah lithium batteries but unable to find any.

Do you know where there are some available to buy?

You won't find individual cells that are 20 or 30,000mah. The best 18650 cells are around 4000mah.

MarkIpswich · 4 Jul 2020 at 21:36

How many of them do I need to make 30,000mah?

Minstadave · 4 Jul 2020 at 22:02

MarkIpswich said:
How many of them do I need to make 30,000mah?

Honestly, if you can't do that maths you probably shouldn't be soldering together Lion cells.

If you buy high quality cells you'll spend more than buying a new battery bank and i wouldnt want to charge them on whatever junk charging circuit your original power bank is likely to have.

Just buy a decent power bank.

mrgubby · 5 Jul 2020 at 10:05

500,000 mAh is 500 Ah. My car battery is 110 Ah.

I know lithium ion batteries have a much higher charge density but I think they may be telling fibs ...

Trifid · 5 Jul 2020 at 10:37

Ah, there is nothing better then wishful thinking specs in low quality ebay specials. I hope you weren't planning on taking it on a plane for both the dubious quality and its rated capacity being way over the legal allowance. This is good quality and as high a capacity that you are legally allowed to take on a plane. https://www.amazon.co.uk/Anker-Powe...=1&keywords=anker+26800&qid=1593941660&sr=8-6

vanandjuanunited · 5 Jul 2020 at 10:45

Think the seller forgot to put in a decimal point somewhere

Yaayuh! · 5 Jul 2020 at 12:32

Trifid said:
Ah, there is nothing better then wishful thinking specs in low quality ebay specials. I hope you weren't planning on taking it on a plane for both the dubious quality and its rated capacity being way over the legal allowance. This is good quality and as high a capacity that you are legally allowed to take on a plane. https://www.amazon.co.uk/Anker-Powe...=1&keywords=anker+26800&qid=1593941660&sr=8-6

That's what we've had for a while now, it's great.

Rroff · 8 Jul 2020 at 06:42

mrgubby said:
500,000 mAh is 500 Ah. My car battery is 110 Ah.

I know lithium ion batteries have a much higher charge density but I think they may be telling fibs ...

Minstadave said:
500,000mah would be about 140 18650 cells and weigh 7kg.

That is just the cells as well - an actual 100-200,000mah li-ion power station will weigh 5-7kg and be getting on for the size of a car battery (which would weigh 3+ times as much) when you include the chassis and all the supporting electronics to actually do something useful with that amount of power (obviously you could do away with some of that for a more simple application).

Orcvader · 9 Jul 2020 at 12:12

@MarkIpswich just refund it, you got scammed. Stick with better reliable brands like Anker, Aukey, RavPower, etc. They will be in lower capacity but the actual capacity will still be more than the fake "500000 mAh" one you have so will last longer.

Invertigo · 10 Jul 2020 at 09:37

The description (underneath where it again claims to be 500,000mAh) states it charges at 1A and takes 6-8 hours to charge fully. That's a maximum of 8000mAh possible capacity, surely? And that's ignoring any inefficiencies in charging. Methinks someone added a couple of extra zeros to the capacity number.

andy_mk3 · 10 Jul 2020 at 09:39

Let BCDC educate

3t3P · 10 Jul 2020 at 22:11

Next thread:

'I bought a submarine battery off the bay that fits in my pocket is it genuine?'

DrGHB · 14 Dec 2020 at 11:23

Glad someone else spotted this nonsense. 500000 mAh... 500Ah? That's a diesel field generator! Higher rated cells should run more efficiently than lower rated for the same load. If a 500000 mAh bank discharges quickly then a. the load is too great (!) or b. it's not 500000 mAh.