YZXStudio 8 Power Bank Review (4x18650)

74 posts / 0 new
Last post
ScottJD
Offline
Last seen: 1 year 2 months ago
Joined: 04/07/2015 - 03:24
Posts: 6
Location: Columbus, Ohio

maukka wrote:
Got the English firmware from Franky today. Update went without a hitch. Seems like my translations were correct, but it still looks much cleaner now.

So I’m curious, is the updating of this firmware for the batterythe same process as updating the USB battery monitors like in this video?
Thanks,
Scott
https://youtu.be/ekHjtYe9fP0
maukka
maukka's picture
Online
Last seen: 2 min 54 sec ago
Joined: 12/31/2015 - 04:15
Posts: 1952
Location: Finland
ScottJD wrote:
So I’m curious, is the updating of this firmware for the batterythe same process as updating the USB battery monitors like in this video? Thanks, Scott https://youtu.be/ekHjtYe9fP0

Yes.

ScottJD
Offline
Last seen: 1 year 2 months ago
Joined: 04/07/2015 - 03:24
Posts: 6
Location: Columbus, Ohio

Nice, maybe it’s time I get a new battery pack since I have plenty of 18650 cells.
My only concern is the way the batteries seem to be wired. I don’t see any balancing between them? Or the pictures I looked at were wrong. I was looking at the 4 cell version.
Does it balance the batteries during charging?
I know it’s not needed as much as for a LiPo pack, plenty of laptop packs don’t do individual cell balanced charging, but charge them in clusters of cells instead.
I think I will get one anyway. It’s probably the one thing I haven’t reviewed or own from YZXStudio.
Scott

ScottJD
Offline
Last seen: 1 year 2 months ago
Joined: 04/07/2015 - 03:24
Posts: 6
Location: Columbus, Ohio

So I decided to order some parts for mine so I can build it since my one 10,000mAh pack had swelled up. Time to get the batteries, the best nickel strips I can get and find a way to spot weld them. So I went back to this review to read the rest of the thread and discovered mine is a version 2. Maybe I should at least power it on to make sure it works also.
Then I saw something about updating the firmware with with an STI programmer but using the micro USB port.
So I clicked on the link and just started laughing. That was he first time I ever clicked a link and it went to my own video. LoL that was funny to me for some reason.

Ok, so I ordered a way to spot weld the cells, should get it next week.
Any recommendations on what cells are the best to use with this. I lost the manual so I don’t remember what the max output is capable of doing. So I’m between the LG for the 15A out so they don’t run hot since it will probably never reach this level out, and the Panasonic ICR because they have 10A out, both comparable capacity but the panasonics are much more stable if something was to go wrong.

I ask about the max output because the nickel strips I use to spot weld and the resistance will matter. I’ll probably end up using 8mm wide pure (>96%) nickel but it’s hard to find with people saying its pure and shipping nickel coated steal. Not worried about the costs, I want this built correctly so it will last for a few years before I have to change the cells again for another few years.

Thank you,
Scott

will34
will34's picture
Offline
Last seen: 2 days 4 hours ago
Joined: 12/18/2012 - 00:12
Posts: 3621

I use GA in mine and they work great. After 30 cycles or so charging at 8A using a 50W laptop adapter and I still see 13.200mAh total capacity. It fully charges in less than 2 hours!

The powerbank gives you the option to charge up to 10A but it will drop when the core temp. reaches 55C.

I wouldn’t worry about output capability of the cell, even at the highest load you have it split into 4 cells.

ScottJD
Offline
Last seen: 1 year 2 months ago
Joined: 04/07/2015 - 03:24
Posts: 6
Location: Columbus, Ohio

Thanks for the reply Will.

I was about to pull the trigger on 4 Sanyo GA, but my thoughts changes slightly now. After looking at the data sheet on the GA being charged at 1.65A and discharged at 6 Amps for cycle life it seem to decline in capacity to 3000mah after about 75 charges.

So I’m looking for fast charging that will also last, yea it’s nice I can change the cells when they get low myself now with this pack.

Now looking at the Samsung 30Q it will also loose 300mah after 75 charges, the difference is the Samsung is being charged at 4 Amps and discharged at 15 Amps.
So the way I’m looking at it now is if I fast charge it with a laptop power supply it will be putting a percentage charge current to a battery that can take a 4 Amp charge and will degrade the cell slower with less loss leaving me with more capacity over a longer time and more charging cycles. But I guess this also depends on how often you fast charge it and use it, or even drain it all the way.

Both are great cells, I own a few Samsung 25R, and 3 other types from Samsung. I also own a few Panasonic 18650B and they are doing great also. The one tool pack I recently looked at for a friend that recently failed was running sanyo cells. It’s for the Weedwhacker and rated for 57watt hours at 24V. But when he told me it stayed on the charger in the garage for the last 4 winters and it just now failed. I was more impressed I only found one bad cell for being frozen a few joints out of the year.

Concidering I just had two USB packs fail (one 10,000mah that never did it’s claimed 2.1A out) and swell up in the last two months I’m tired of LiPo packs for USB portable power. Their still great for RC cars and drones, just not portable power.
The other great feature is the honest reporting of capacity, not some company saying it’s a 10000mah pack just because they put a 10000mah LiPo battery in it. They never concider the energy used by the boost ormghe efficiency of the ciurcut. So it will be nice to know how much power I really have left in the pack.

Soon, soon it will be built. I just need to make up my mind in the batteries, lol.
Scott

will34
will34's picture
Offline
Last seen: 2 days 4 hours ago
Joined: 12/18/2012 - 00:12
Posts: 3621
ScottJD wrote:
The other great feature is the honest reporting of capacity, not some company saying it’s a 10000mah pack just because they put a 10000mah LiPo battery in it. They never concider the energy used by the boost ormghe efficiency of the ciurcut. So it will be nice to know how much power I really have left in the pack.

The displayed capacity is measured from the cells, before any conversion / efficiency loss. The difference is that it measures the real capacity vs spec capacity, which is only achievable in optimal lab testing conditions. e.g. a Sanyo GA only has about 3,350mAh real capacity.

I have the 7th gen YZX powerbank also with 4x Sanyo GA, this one has been heavily used for almost a year and the cells have over 200 cycles now. They charge at 1.1A to 4.2V and discharge down to 2.5V everytime. The capacity has dropped from 13,250mAh to 12,500mAh now, which is still 3,150mAh per cell, so I wouldn’t worry about cycle losses with the GA.

Keep in mind that the spec sheet is based on 6A output, in real use you will never see this kind of discharge rate. The max output is 15W on the 5V side and 24W on the QC side. Assuming 85% efficiency:

47W power draw / 3.7V = 12.7A / 4 = 3.1A per cell

If you’re still unsure about the GA, LG MJ1 and Samsung 35E are also good cells, recommended by the YZX guys themselves.

ScottJD
Offline
Last seen: 1 year 2 months ago
Joined: 04/07/2015 - 03:24
Posts: 6
Location: Columbus, Ohio

Thanks, I decided to go with the GA in the end.
I can’t trust that the nickel strips coming with the spot welder will be pure nickel, it’s probably plated steel. So another concideration was the temperature the batteries reach durring certain charge currents. I want to run this cool, and nickel plated steel will also heat up more. So I think I finally found a US seller for our nickel and maybe the whole thing will be up and running next week?
But it also might take a few days to test the nickel, and I want to load test each cell before I weld them together. But soon, soon it will charge things.
I did put one cell on it to make sure the electronics booted up today. It looks good. But I didn’t go over settings.
Scott

angerdan
angerdan's picture
Offline
Last seen: 1 hour 9 min ago
Joined: 11/01/2015 - 10:07
Posts: 429

maukka wrote:
I also like to rate my power banks by their energy/weight ratio (Wh per kilogram).
It is also the highest energy density of my 4 cell power banks.

Comparison between four 4×18650 battery banks. The YZXStudio is a clear winner in the energy density category.


Comparison table between those same battery banks.

Efficiency is calculated by dividing the output energy by the measured (if possible) energy in Wh of the cells inside (discharging down to 2.8 volts). For the YZXStudio and the Tomo it was calculated from my own measurements of the exact same NCR18650GA cells with a SkyRC MC3000.
Most well designed power banks with high capacity cells lie in the 120-130 Wh/kg range.
These include for example Poweradd Apollo 3 (LiPo, 125 Wh/kg), Anker Powercore 3350 mAh (1×18650, 119 Wh/kg), Huawei AP007 14000 mAh (4×18650, 120 Wh/kg) and Tensai TB-15600 (6x Samsung 18650-26H, 125 Wh/kg).


But you’d eqip the TOMO with low capacity batteries.
I use Panasonic NCR18650B 3,7V 3400mAh (PCB, Button Top) cells with 46g each.

So it’s just 86+(4×46)=270g for 50,32Wh; 186,37Wh/kg for the TOMO M4.

maukka
maukka's picture
Online
Last seen: 2 min 54 sec ago
Joined: 12/31/2015 - 04:15
Posts: 1952
Location: Finland

Check again. I used Sanyo NCR18650GA. The power bank output 31.8Wh with those 3500mAh cells.

angerdan
angerdan's picture
Offline
Last seen: 1 hour 9 min ago
Joined: 11/01/2015 - 10:07
Posts: 429

Oh, so you mean the electronic circuit of the TOMO has high drain/low efficency?

Another question, how’s the YZXStudio Power Bank 8× (27600mAh) looking?
Whats the physical difference to the 4×18650?
Are there any pictures?

maukka
maukka's picture
Online
Last seen: 2 min 54 sec ago
Joined: 12/31/2015 - 04:15
Posts: 1952
Location: Finland
angerdan wrote:
Oh, so you mean the electronic circuit of the TOMO has high drain/low efficency?

Yes, check the table. The Tomo is 67% efficient while the YZXStudio is 94% on the same 18650GA batteries.

angerdan wrote:
Another question, how’s the YZXStudio Power Bank 8× (27600mAh) looking? Whats the physical difference to the 4×18650? Are there any pictures?

It’s exactly the same as the 4×18650 one except for the case that is longer to house the four extra batteries. No difference in electronics.

rubatone
rubatone's picture
Offline
Last seen: 2 months 2 weeks ago
Joined: 08/18/2017 - 04:28
Posts: 32
Location: Sweden

I would love a BLF group-buy on a powerbank like this!

angerdan
angerdan's picture
Offline
Last seen: 1 hour 9 min ago
Joined: 11/01/2015 - 10:07
Posts: 429

Me too!
Could be an EU groupbuy maybe.
Perfect would be if someone can solder good cells into the powerbank, since shipping from Hong Kong is prohibited or expensive.
Franky Tongs price for 4/8cell version is $73/$76 per piece including shipping. So groupbuy could be less.

Franky also wrote me:

Quote:
YZXstudio recommends the following cells:
Sanyo 35E or Sanyo GA 3450mAh, 23mOhm internal resistance, supports up
to 3A charging and 8A discharging.
Samsung 30Q or Sony VTC6 3000mAh, 13mOhm internal resistance, supports
up to 5A charging and 20A discharging.

Do not use protected cells, as they are too large to fit in the case.
The most important spec is the maximum charging current, as the power
bank supports very high current charging. Don’t use anything that
supports less than 2A of charging current.

Creating a new thread for the groupbuy would be a good one too separate the topics.
http://budgetlightforum.com/forum/marketplace/commercial/liaisons

rubatone
rubatone's picture
Offline
Last seen: 2 months 2 weeks ago
Joined: 08/18/2017 - 04:28
Posts: 32
Location: Sweden

As I said, a groupbuy on this charger and I´m superinterested, seems to be very difficult to import to Europe.

Rechmp
Offline
Last seen: 1 year 11 months ago
Joined: 11/19/2014 - 03:56
Posts: 7
Location: Crimea

Hello guys.
I just got my powerbank and its just awesome!
I’ve soldered inside 4*3500 Sanyo cells and it shows 13.400mAh capacity. By the way it was pretty hard to put inside even not soldered cells – enclosure was too tiny. And after I solder it with usual 80w soldedrer it wasalmosy impossible to put it inside with pcb, but I did it wit a some cell tube scratching. I think its not a problem that “-” will be on case.

Language of interface was not a problem to understand what is what, but I prefer English one. Tell me please where I can get firmware? Franky’s store don’t work anymore. My current firmware is 8t-2.11-0916.

And one more question: How I can enter menu with calibrations? Long press for any but to just power off bank :\

Thank you for help.
Regards, Sergii.

maukka
maukka's picture
Online
Last seen: 2 min 54 sec ago
Joined: 12/31/2015 - 04:15
Posts: 1952
Location: Finland

Long press the rightmost button on the last information screen to enter settings and calibrate the battery capacity.

Rechmp
Offline
Last seen: 1 year 11 months ago
Joined: 11/19/2014 - 03:56
Posts: 7
Location: Crimea

Thank you maukka, now I got it. Also I discovered that I have 7more submenu points in 16th menu. And main menu order not as yours.

Tell me please where I can ask for eng firmware?

mrheosuper
Offline
Last seen: 1 day 58 min ago
Joined: 09/30/2016 - 12:44
Posts: 1488
Location: Ho Chi Minh City, Vietnam

Hello, where can i purchase this powerbank

Forgot my pen

Rechmp
Offline
Last seen: 1 year 11 months ago
Joined: 11/19/2014 - 03:56
Posts: 7
Location: Crimea
Rechmp
Offline
Last seen: 1 year 11 months ago
Joined: 11/19/2014 - 03:56
Posts: 7
Location: Crimea

Woooooooo! There is English language inside!

To enable open menu by long press right button on the screen with version
Scroll down with right button to 16th point
Long press right button
Choose 25th menu point
Long press right button
Choose “En” by right button
Long press right button
PROFIT!

maukka
maukka's picture
Online
Last seen: 2 min 54 sec ago
Joined: 12/31/2015 - 04:15
Posts: 1952
Location: Finland

That’s cool! Before you had to get hold of the English firmware and flash it.

Rechmp
Offline
Last seen: 1 year 11 months ago
Joined: 11/19/2014 - 03:56
Posts: 7
Location: Crimea

Yeah. That’s why I bought stm programmer, but looks it’s useless now.

iloveelectronics
Offline
Last seen: 1 year 11 months ago
Joined: 10/17/2017 - 22:47
Posts: 4
Location: Hong Kong
Rechmp wrote:
….. Franky’s store don’t work anymore.

Sorry guys. My store was closed for about a week as I was very busy packing stuff up at home to prepare for my move overseas. The store is now open again. Unfortunately I will not be carrying any YZXstudio products anymore. I made a post on the EEVBlog forum a while ago explaining the reason: http://www.eevblog.com/forum/chat/starting-a-new-chapter/msg1302891/

—Franky

Dr.GSM
Offline
Last seen: 1 year 10 months ago
Joined: 12/16/2017 - 18:08
Posts: 1
Location: France

The concept is exciting, but the batteries are put in parallel, or without ORing MOSFET control, the weaker battery will kill the others. The iPad batteries are connected via ORing MOSFET control, which is the “secret” for battery longevity.

XD9
XD9's picture
Offline
Last seen: 1 month 1 week ago
Joined: 01/11/2018 - 16:16
Posts: 96
Location: United States

How can I buy this power bank?

angerdan
angerdan's picture
Offline
Last seen: 1 hour 9 min ago
Joined: 11/01/2015 - 10:07
Posts: 429
XD9
XD9's picture
Offline
Last seen: 1 month 1 week ago
Joined: 01/11/2018 - 16:16
Posts: 96
Location: United States
BlueSwordM
BlueSwordM's picture
Offline
Last seen: 3 hours 55 min ago
Joined: 11/29/2017 - 12:34
Posts: 5398
Location: Canada

Is it normal that I can’t find any XYZStudio products in BuyInCoins?

Is it also normal that I can’t login in even if I registered?

Finally, how I actually use a Taobao agent? Sorry, first time done it.

My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547

BlueSwordM
BlueSwordM's picture
Offline
Last seen: 3 hours 55 min ago
Joined: 11/29/2017 - 12:34
Posts: 5398
Location: Canada

Bump. Sorry.

My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547

Pages