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Member Since: June 27, 2011

Country: United States



Lighting the way for safer cycling for all.


designer, pitch man, fundraiser, patent writer,

Spoken Languages

English and LED

Programming Languages

Wonderful languages of the past that Google doesn’t even list on their job application, as one for of their age discrimination practices. Anyone remember 1750A assembler? APL? Pascal? even Watfiv?


Rutgers College, the real tough top 10% of the hs class admission requirement school before it got glopped into one big unversity.


Self taught LED bicycle lighting expert.


LED bicycle lighting and related electronics and product design.




See my executive abstract at http://www.facebook.com/people/Barry-Beams-Bicycle-Lighting/100001655731941

  • What is the threshold voltage for the status LED? What does it mean when the stat LED flashes green? It comes on solid when charging from Sparkfun’s recommended 1000mA charger, but blinks green when I use Sparkfun usb to barrel jack adapter cable powered from either a USB jack cellphone charger 650mA wall wart or a computer USB jack. The battery’s voltage was 3.6V when I put it on the charger, so its not an issue with the battery already being over a threshold voltage. Overall, seems like a good unit and it does put out the rated 1A charging current. Btw the board could easily be cut down much smaller, and soldered to instead of using the output jack.

  • This time limit concerns me too, since I’ll be charging 400mAH and higher battery capacities, needing a minimum of 3.5 hours at 1000mA charge current. If I’m reading your posting correctly, does the status light indicate charged after 1.5 hours regardless of state of battery? If so, then please give an equation that I can calculate either a replacement capacitor or a second capacitor in parallel. Thank you, Barry

  •  Can anyone suggest the bare minimum beside the two resistors to give me a 1 amp max output current?
     To charge an LI battery at 4.2V, the calculator shows me I should use R2=570 ohms.  But how can I determine how much current this will pass to the batteries? Specs on this list a 1.5A output current. I need to limit charge current to 1.0 Amps for safety, as per standard lithium ion safe practices.

    Would it be simple as calculating the correct RsubS value shown under load regulation on page 8 of the spec sheet? Is there an equation or calculator to determine RsubS? I’m severely limited on space too, no larger than what the Sparkfun Lipoly USB basic charger takes up, and no taller than a 2.1mm barrer connector. tia, Barry, bike light designer at Barry Beams Bicycle Lights

  •  Do Not Buy This if you will be imbedding it in any project where it can't be easily removed.  

    The MTBF for a micro USB jack is 10,000 insertions. The poorly attacked jack on this item didn’t last even 100 uses. Now I’m stuck with a mass of nearly impossible to remove epoxy where the microUSB jack and circuit board used to be, and no realistic way to remove it without destroying the light housing.
    Seriously, do not buy this until the design is changed so the jack is properly affixed THROUGH the board so that it won’t break off instead of weak reflow that has effectively no structural shearing resistance, and will weaken with each insertion and removal until the jack breaks off the board despite the carefully applied powder doped epoxy that I used to attach it.
    Also, it fails to charge the batteries completely. It cuts out at 4.12 to 4.15 volts instead of a complete 4.2V charge.

  • Btw, for a guy relearnig his HS electronics after 30 years, what is Vripple and Fmin?
    thx again,

  • Will this chip let me step up 5V input from a USB jack to 12.6V that I need to have to charge 3 LI cells in series? I know its not ideal but need to be able to show as proof of concept

  • Can this be made or adapted to charge multiple LI cells in series, for example to boost the 5vdc input to 12V instead of regulating down to 4.2?
    OR do you have another product that will?
    Thank you.

  • Can this be made or adapted to charge multiple LI cells in series, for example to boost the 5vdc input to 12V instead of regulating down to 4.2?
    OR do you have another product that will?
    Thank you.

  • Can this be changed on the fly to charge to 4.35 Volts instead of the preset 4.2V?

  • Build two in parallel.

No public wish lists :(