what battery to select?

[sml2010]

Hello

I need have a LED light with below specification :

Power: 3 x 3W
Color BIN: White
Rated Voltage: DC 8~26V
Luminous Flux: 500LM


Can you please help me to find a battery for these LED with constant use 8 hour?
I need a rechargeable lithium ion battery? how can i charge this battery with usb cable?

I am wait for your reply

thank you

 

[HMS1021]

Re: what battery select?

There are 1000s of gadgets ranging from power tools, garden tools, etc out there. Most use NIMH batteries because they do not have a memory like NiCad but can supply high current. Shop for a couple of batteries and a replacement charging stand for one of these tools that matches your price point. I would look on Amazon. I would look for 12v and at least 10,000ma/h (10A/h).

If size and weight are important then Li-Ion is the way to go but they cost more and you must be very careful charging them due to the fire risk. Here too you may find an existing replacement charger/ battery pair that will work.

 

[tpetar]

Re: what battery select?

3 x 3W = 9W

9W for 8h = 72Wh

I will say you need good and high capacity battery, such as lead acid, big Li-Ion/Po or NiMh pack.


Best regards,
Peter

 

[kam1787]

Re: what battery select?

Lead acid would be cheaper but you would be looking at a 12V battery - so you could not recharge directly from USB - you would need a DC-to-DC converter followed by a charger - the current provided by USB is low (up 500mA but only 100mA is assured), so recharging time might be days.

 

[tpetar]

Re: what battery select?

No USB 2.0 can give around 2A on most motherboards per port (newer motherboards). USB 3.0 can give several Amps.

But, I try to direct on amount of power needed for this 8h for 9-10W.



Best regards,
Peter

 

[HMS1021]

Re: what battery select?

The USB.org USB 2.0 spec is 500ma max and SMSC devices enforce this very well but I believe you are right. I have been surprised at the number of high power device I can plug in without getting the over current message on my new Xeon board.

 

[kam1787]

Re: what battery select?

Power Handling Capabilities: As with previous USB versions, USB 3.0 ports come in low-power and high-power variants, providing 150 mA and 900 mA respectively while simultaneously transmitting data at SuperSpeed rates.[17] Additionally, there is a Battery Charging Specification (Version 1.2 – December 2010), which increases the power handling capability to 1.5 A but does not allow concurrent data transmission.[15] The Battery Charging Specification requires that the physical ports themselves be capable of handling 5 A of current[citation needed] but the specification limits the maximum current drawn to 1.5 A.

https://en.wikipedia.org/wiki/Universal_Serial_Bus

 

[tpetar]

Re: what battery select?

The USB.org USB 2.0 spec is 500ma max and SMSC devices enforce this very well but I believe you are right. I have been surprised at the number of high power device I can plug in without getting the over current message on my new Xeon board.

Lots of board have this higher current support. I talk in content of power delivery not for specification. But for specification you are right. Manufacturers sometimes improve their products on own hands. I think more in practical way.

https://www.gigabyte.com/microsite/239/3x-usb-power.html

You can open web site of some motherboard manufacturer you will find lots of products with 3x USB power.


By the way, USB 3.0 connectors are designed for higher currents, even to transfer 100W.



We have not heard lately sml2010.


Best regards,
Peter

;-)

 

[kam1787]

Re: what battery select?

USB 3.0 connectors are designed for higher currents, even to transfer 100W.

Ohhhhhhhhhhhhhhhhhhhhh do you know the AWG required for 20A [at 5v] ? There is no way I would rely on such a small connector and wiring to handle anymore than 500mA

 

[tpetar]

Re: what battery select?

Ohhhhhhhhhhhhhhhhhhhhh do you know the AWG required for 20A [at 5v] ? There is no way I would rely on such a small connector and wiring to handle anymore than 500mA

100W also can be 20V 5A. 20V from USB can you believe ? :smile:


I dont want to hijack thread with USB things, but here is some short informations:


USB Power Delivery
http://www.usb.org/developers/powerdelivery/

New USB standard will deliver up to 100W of power
http://hexus.net/tech/news/peripherals/42705-new-usb-standard-will-deliver-100w-power/
**broken link removed**
http://www.maximumpc.com/article/news/100w_power_delivery_spec_approved_usb_20_and_30
http://www.neowin.net/news/say-goodbye-to-power-cords-with-usb-30-update


USB Power Delivery offers the following features:

- Increased power levels from existing USB standards up to 100W.
- Power direction is no longer fixed. This enables the product with the power (Host or Peripheral) to provide the power.
- Optimize power management across multiple peripherals by allowing each device to take only the power it requires, and to get more power when required for a given application.
- Intelligent and flexible system level management of power via optional hub communication with the PC.
- Allows low power cases such as headsets to negotiate for only the power they require.

Examples:

- Enables new higher power use cases such as USB bus powered Hard Disk Drives (HDDs) and printers. This eliminates the need for a separate power brick.
- A monitor with a supply from the wall can power, or charge, a laptop while still displaying.
- USB power bricks or chargers are able to supply power through a laptop’s USB ports.
- Laptops and USB power bricks can provide higher power to battery powered devices (not currently defined by USB).
- Battery powered devices can get increased charging current from a hub and then give it back temporarily when the user’s HDD requires to spin up.

**broken link removed**

**broken link removed**

**broken link removed**



Video examples:

Power Your Monitor with USB!
http://www.youtube.com/watch?v=LvB9gIWzjo0

USB-IF Demonstrates USB Power Delivery Charging Notebook
http://www.youtube.com/watch?v=t312usPb9CI



Dont mix USB 2.0 and USB 3.0 cables and connectors they are not the same, even all connectors are different. There is some partial compatibility and similarity but difference is obvious.


USB 3.0 Promoter Group Announces Availability of USB Power Delivery Specification
USB Power Delivery extends popular USB battery charging to support higher power devices
http://www.usb.org/press/USB_Power_Delivery_Spec_Completion_FINAL.pdf

"HILLSBORO, Ore. – July 18, 2012 – The USB 3.0 Promoter Group, in conjunction with the USB 2.0 Promoter Group, today announced the completion of the USB Power Delivery specification, which enables increased power delivery through USB cables and connectors. The specification expands cable bus power capabilities in USB applications, supplying higher voltage and current to deliver power up to 100 watts over USB Power Delivery certified cables. It is capable of delivering higher power to charge notebook PCs and power external hard - disk drives, devices which previously did not receive adequate power from traditional 5V bus power. The USB Power Delivery specification enables a switchable source of power withoutchanging cable direction. Existing USB cables and connectors are also compatible with this specification and will coexist with the USB Battery Charging 1.2 specification as well as existing USB - bus powered applications."



USB 3.0 SuperSpeed update to eliminate need for chargers
http://www.techspot.com/news/52321-usb-30-superspeed-update-to-eliminate-need-for-chargers.html

Profile 1: 5V @ 2.0A
Profile 2: 5V @ 2.0A or 12v @1.5A
Profile 3: 5V @ 2.0A, 12V @ 3A
Profile 4: 5V @ 2.0A, 12V or 20V at 3A
Profile 5 : 5V @ 2.0A, 12V or 20V at 5A

20V x 5A = 100W :wink:



Maybe this post gives new thinking about this. But I dont support idea to charge lead acid over PC motherboard, better use dedicated iron transformer based safe charger for this purpose. Lead Acid batteries are invented in 1859 and these type of batteries are the oldest type of rechargeable battery and deserves respect, also PC should be used for smarter purposes, such as writing firmware for some uC, but its good to know that we can crank car engine at cold winter. :smile: (this for cranking is joke)



I hope that there will be no smoke from connectors! :smile:



Best regards,
Peter

;-)

 

[tpetar]

Re: what battery select?

One question for sml2010, this device should be handheld (movable) ?


You can look hand lamps like Police or similar which uses Li-Ion based batteries 18650 or bigger, but working time will be much lower than 8h. But zou can have several battery sets on standby for replacing. I have Police 12000W with CREE T6 LED chip 1200lumens two 18650 are used, and Police 8000W with CREE Q5 500lumens one battery is used.



Best regards,
Peter

:wink:

- - - Updated - - -

12000W and 8000W are ID of product not Watts!

 

[kam1787]

Re: what battery select?

did the OP go up in smoke?

 

[tpetar]

Re: what battery select?

did the OP go up in smoke?

I hope original project is still current, and that owner of thread did not try to connect some power inverter on USB port to see motherboard limits.

 

[HMS1021]

Re: what battery select?

I connected a variable resistor and current meter across the +5V and ground USB 2.0 pins on a connection with a external hub. The keyboard and mouse are connected and powered by the hub. There is nothing else on any internal or external USB 2.0 connector. At 590ma the port disconnects and I can no longer see the hub in device manager. At 460ma it re-remunerates and functions normally except I lose the mouse until the next normal reboot. This is repeatable on several USB ports. There are no error messages in Windows. If I boot up with the 590ma load I get a USB OVER CURRENT message on the BIOS screen.

I have gone through the BIOS and mobo manual looking for a over-ride for the current setting or error and did not find anything. I did discover a Asus Windows app switch that permits the USB to be powered during sleep and stand-by which is useful when charging my phone.

tpetar thank you for the tip on the USB Charging Port in the USB.org spec. Neither my ASUS P5Q or Sabertooth Z77 have this feature but now I know it is available, we will adopt it in a product we are developing.

Mother board: Asus Sabertooth Z77 with a I7-3770K
Windows 7 Pro 64

 

[tpetar]

Re: what battery select?

Its good during product buying process to pay attention on product capabilities and features. Gigabyte manufacturer have 3xUSB Power even on older motherboards. I measure earlier car navigation device drain 1,2A from port. Also supplied current will depends from used device and motherboard port capabilities.



Best regards,
Peter

:wink: