Sold/Expired Sales Thread: USB Micro Charger for Li-Ion/Poly Cells

[Illum]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

I'm in for one, maybe two if the first works well

For those long trips where I'll need to charge my EDC's 17670s when there is no grid power

Whats the current draw from USB? I have one of those portable power packs with a USB socket but its 500ma max

 

[donn_]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

I'd be in for one if it was offered in a 'goosed' version. 300mA is too slow for me.

 

[Sabrewolf]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

This is a nice charger since I'm always next to the computer!

Quick questions:

Will these work with the LifeP04 cells?
Will there be a termination circuit? I mean will the circuit turn off at a certain voltage?

Thanks.

Tis allready covered in the first post But yes, It shuts off at 4.2v
And it will not charge a LifePo4 batt.... But, I may try to make one
with a different charging circuit to handle them

I'm in for one, maybe two if the first works well

For those long trips where I'll need to charge my EDC's 17670s when there is no grid power

Whats the current draw from USB? I have one of those portable power packs with a USB socket but its 500ma max

It should run just fine from that pack The average supply current
is about 450mA or so. But it varies a little with the battery and Usb port.

I'd be in for one if it was offered in a 'goosed' version. 300mA is too slow for me.

Maaaaaaybeee But it won't work from a Usb port

 

[donn_]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

Maaaaaaybeee But it won't work from a Usb port

Guess that sorta defeats the purpose, eh?

I've got faster chargers which plug into the wall. In fact, a 6A model arrives tomorrow.

I take it the USB port itself has output limitations?

 

[Sabrewolf]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

Just to let you all know
I just sacrificed my prototype to find out if reversing the leads
on the battery will cause a problem... Well, it went :mecry:
So this circuit does NOT have reverse battery protection!
That is another reason why i am using red/black leads
Although, You CAN short the leads together for a short time
without any damage

 

[RocketTomato]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

USB 2.0 provides up to 500 mA per port. (USB 3.0 has a 900 mA limit.) You can always try a dual headed cable to double the charge rate.

 

[donn_]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

USB 2.0 provides up to 500 mA per port. (USB 3.0 has a 900 mA limit.) You can always try a dual headed cable to double the charge rate.

Actually, USB 2.0 includes a little documented feature called "Battery Charging Specification 1.0." It can take a dedicated power supply and provide up to 1.8A. But it seems that would require either a wall plug-in, or a board in the PC to power the power supply.

 

[netprince]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

I'm interested in one please... :thumbsup:

EDIT: I wouldn't mind the 4.1v cutoff either, but thats probably hard coded somewhere right?

BTW, would be interesting to connect this to a solar panel somehow, how efficient do you think it is?

 

[Sabrewolf]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

I'm interested in one please... :thumbsup:

EDIT: I wouldn't mind the 4.1v cutoff either, but thats probably hard coded somewhere right?

BTW, would be interesting to connect this to a solar panel somehow, how efficient do you think it is?

It could be easily connected to a solar panel.
The panel would need to supply at least 500mA @ 6v or less.
But i wouldnt bother with 18650's on that setup.. You would
need at least 8 hrs of full sunlight for a dead batt. 123's would
be fine under the same solar panel specs. That would take about
3 hrs for a dead 123 meethinks.

 

[Sabrewolf]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

Actually, USB 2.0 includes a little documented feature called "Battery Charging Specification 1.0." It can take a dedicated power supply and provide up to 1.8A. But it seems that would require either a wall plug-in, or a board in the PC to power the power supply.

The Usb 3.0 port is supposed to supply 1800mA meethinks.
No extra adapter is neccessary. At least thats what i remember

 

[jp2515]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

Tis allready covered in the first post But yes, It shuts off at 4.2v
And it will not charge a LifePo4 batt.... But, I may try to make one
with a different charging circuit to handle them

:bow:

 

[wrencher]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

One please.

Jeff

 

[Illum]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

USB 2.0 provides up to 500 mA per port. (USB 3.0 has a 900 mA limit.) You can always try a dual headed cable to double the charge rate.

not if both of those USB jacks are from the same bus, some USB hubs with no external power are every jack on the same bus...so if you draw 500ma from one port it may render the others useless. I think this applies to the 1.0 hubs

Also, there is what they call now "Power ports" at comes in USB female but its either 5 or 12V specifically used to charge devices.
I've only seen it once on a store display USB hub...how those work I dunno.

 

[tino_ale]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

I understand it doesn't have reverse polarity protection on the output, but does it have a short-circuit protection ?

What happens if you make contact with between the two charging leads?

Thanks

 

[Sabrewolf]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

I understand it doesn't have reverse polarity protection on the output, but does it have a short-circuit protection ?

What happens if you make contact with between the two charging leads?

Thanks

Yup, I allready covered that one Short-Circuit Protection :thumbsup:

 

[Sabrewolf]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

:bow:

I found a charging circuit for the LifePo4 batteries :thumbsup:
Got some on order to play with. So i will eventually
have 4 chargers.. High-Power Li-ion/Poly/IMR and LifePo4.
And then the little USB dongles for both. But for now,
The little guys go first. The big ones will be a Multi-Bay
setup with full regulation, And shutoff just like the little
guys, But with Alot more charging current (1-3 amps)

Stay Tuned!

 

[Varriano]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

Put me down for 2. These look great. Will keep one at work and one goes with me.

Thanks.

V.

 

[scout24]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

I am beginning to wonder if Robert ever sleeps...

 

[Sabrewolf]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

I am beginning to wonder if Robert ever sleeps...

What is this "Sleep" thing you speak of? :nana:

 

[Sabrewolf]

Re: Feeler: USB Micro Charger for Li-Ion/Poly Cells

Just made a Production version with magnets soldered to
the alligator clips. I will be using some slightly larger magnets
for the ones that are shipped out. As they don't have quite
the pull to attach to a protected battery.

Here are the internals before i seal them up with Norland 123k:



And the Alligator/Magnet clips


Strain Relief: