usb charging questions /confusion

[steveo3002]

i have a gadget thats usb only charge , stamped on the battery is 7.2v

i see most of my usb sockets say 5v

does 5v somehow charge up to 7.2v or do i need a socket thats at least 7.2v

asking as the gadget is displaying symtoms of not charged , so that would explain it

 

[MetalMonkey]

7.2v sounds like a two cells, so it will depend a lot on the charging circuity as to whether it charges and balances the cells or does some voltage conversion or not.
Further details on said gadget are required really otherwise you are pretty much guessing.

 

[hotponyshoes]

Some usb chargers output 9v now. (and higher)
I've got a few devices that won't charge from a normal 5v usb charger

 

[sako243]

USB C PD can negotiate up to 48V from the charger.

USB Charger (USB Power Delivery) | USB-IF

www.usb.org

 

[sako243]

Although there's nothing stopping the charger having a boost circuit in it. Is it USB C? If not then either a boost circuit internally or they've reused a USB connector for other purposes, a bit sly / dangerous.

 

[steveo3002]

7.2v sounds like a two cells, so it will depend a lot on the charging circuity as to whether it charges and balances the cells or does some voltage conversion or not.
Further details on said gadget are required really otherwise you are pretty much guessing.

chinese model helicopter , info is scant

 

[steveo3002]

i have a powerbank with usb3 , that ought to do it right?

 

[sako243]

Not necessarily. Depends on if it supports USB 3 PD or not. They were all designed to be backwards compatible to a certain extent so with basic wiring adapters you didn't risk blowing things up.

 

[steveo3002]

Not necessarily. Depends on if it supports USB 3 PD or not. They were all designed to be backwards compatible to a certain extent so with basic wiring adapters you didn't risk blowing things up.

so to be sure i need a charger socket that says 5/9/12v on it vs 5v only?

 

[sako243]

No idea, there's no hard and fast rules over it. But something designed for laptops or bulkier equipment is more likely to. You may find a wall wart that does it.

I'm sure if they do they'll make a song and dance about it.

 

[northwest]

Interestingly and on this subject. I have a pair of Bowers and Wilkins P17 earbuds and last Saturday they decided they just weren't going to work, at all. Not even take a charge, nothing, totally dead. So I emailed Bowers and Wilkins support and a very nice chap got back to me telling me to unplug the usb charging lead from the wall socket and plug it into a laptop as that would work, to my amazement it did. The chap maintained that it was because they were "intelligent" now and the laptop would best be able to work out what charge it needed? Bloody witchcraft as far as I can tell, but it has worked.

 

[hotponyshoes]

Have a look at any phone chargers you have, newer Samsung and Sony ones provide higher voltage.
It's supplied on demand so you can't damage anything (providing for post #5!)

 

[voipio]

Does the supplied charging cable have USB-C connectors on both ends? If not, and one end is the "classic" USB-A, large rectangular connector, then the chances are the device should charge off the standard 5V and boost the voltage internally.

Having a USB charge monitor, somethng like the link below, is extremely handy for diagnosing issues. The linked one has separate USB-A and USB-C inputs/outputs. It will only monitor one at a time, but it's helped resolve a few issues here, including being able to diagnose, in advance, that the wife's power bank is on its way out, and needs replacing.

https://www.amazon.co.uk/Detector-Voltmeter-Ammeter-Digital-Capacity/dp/B0B9S6HRNL

One quirk of properly implemented USB-C PD chargers is that, when the charge meter is plugged into a USB-C PD charger, the display on the meter stays off, until a USB-C device is plugged into the meter. Then it is possible to see the voltage that's been negotiated via the PD signalling that takes place, and the resulting current drawn.

 

[steveo3002]

Supplied cable

 

[voipio]

That'll be a USB-C connector, then. What's on the other end of the cable?

 

[steveo3002]

just the orignal square usb

 

[carbon]

The chap maintained that it was because they were "intelligent" now and the laptop would best be able to work out what charge it needed?

I have a couple of torches that will charge from a dumb charger at about 0.5 amps 5v but when connected to a smart charger they charge a lot faster at 2.0 amps 5v.

 

[m_c]

To give a bit more detail behind @voipio 's post, the significance of the USB-C plug, is that it signifies the device might be capable of higher current/voltage charging.

By default, USB is 5V at 500mA.
The older A/B connectors could potentially provide up to 2A IIRC, with the source capability described by a resistor across the data pins. (I say described, as the source would output it's max current regardless, but the resistor lets the device know that the charger is capable of supplying higher currents. Any device built to the USB standard, shouldn't pull more than 500mA, unless it recognises a high output source).

With USB-C, it signifies a full communication protocol between the device, and source (I'd say charger, but the source can equally be a computer port). This lets the device and source establish each others capabilities, and set a voltage and current limit as required, which could be up to 5A at 48V.

However, in this implementation, I'd probably expect the device to have a built in boost converter for charging, but it might need a high output charger to function correctly.
To implement the full USB-C power delivery protocol, it needs an additional USB management chip, which on low cost items they won't add, they'll simply fit a USB-C port and just rely on basic 5V power without any of the additional management.

 

[Misterg]

i have a gadget thats usb only charge , stamped on the battery is 7.2v

...

does 5v somehow charge up to 7.2v or do i need a socket thats at least 7.2v

asking as the gadget is displaying symtoms of not charged , so that would explain it

chinese model helicopter , info is scant

To get back to the question: I'd be 99.9% certain that the helicopter will have a charge controller in it that converts the 5V from the USB to the correct voltage for charging the battery, manages the charging cycle and usually works a tell-tale LED of some sort to indicate that charging is taking place / is complete.

Try different USB lead / different charger / different battery.