UPS?

anyone have one of these?

“6x18650 power bank 5V 6V 9V 12V USB 18650”

https://www.amazon.com/LIYUDL-Mobile-Battery-Charger-Adapter/dp/B072F56ND4

usb

i wonder these things:

how do you set the output voltage? apparently it is variable

how waterproof is it?

can it be a ‘ups’?
(that is, run a device from its outputs, when AC goes off, DC continues to the device, like a running a security camera for instance)

they seem to be everywhere, amazon, aliexpress, bang good, ebay, many other shops

i see prices from $8 to $45
some come with cables and adapters, others do not

wle

I don't think it's a UPS.

A UPS has electrical outlets so that you can plug electronics into it.

It’s not a UPS for sure. As said, those take DC and turn it to AC for devices like PC’s and printers or routers to plug into. This is fixed 5V output for USB devices. On the current is varied and selected by the different USB outputs. It has a PCB inside with a boost circuit and USB outputs plus some charging circuits for the batteries. Get a good quality one. The cheap ones are JUNK. I got a couple of them and they never deliver the full capacity from the batteries and only charge my 3300mah phone battery 1.5x’s before it shows 0 volts off of eight 18650 2200mah batteries.

Agreed go for a quality bank, But you also got to consider the capacity of the device as well as factor of general draw current of the fixed 5V for USB and 18650’s typically draw at 3.7 V. So the eight 2200mah batteries would be only around 13000mah total after conversion but then consider the efficiency of circuit that’s handling the boost to meet the 5V for USB charging lets say 70% efficiency though that might still be high depending on how “junk” it is leaves you with around 9000mah to play with but since the circuit handling charging aspect will also lose some of that capacity through heat etc the 1.5x charge of the 3300mah phone seems accurate. =D

when i said UPS i meant UPS for USB devices.

my idea would be:

connect this thing to AC, let it charge the 18650s
its output goes to something on 5V USB like a security camera
when AC goes out, the 5V USB continues but now it is powered by the 18650s
(WITHOUT you having to go press a button to make it switch over)

will it do that?

i realize it is a power bank
some of them do this, some do not
and no one ever tells you what they really do

wle

Probably, but a normal UPS only switches to battery power when power is lost, if this is just a power bank it will be charging and discharging the batteries at the same time, so that will cause wear on the cells constantly being used and then topped off over and over.

It seems you didn’t read my posts here: