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
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.
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
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.
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 :\
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!
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: Starting a new chapter - Page 1
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.
