Idea for lights, no dc dc convertor needed.

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Spacey   100 kW

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Idea for lights, no dc dc convertor needed.

Post by Spacey » Sep 08 2010 4:08am

I was thinking about buying one of these:
http://cgi.ebay.com/12V-27W-LED-Running ... 2a0a05808f

Which run at 12 volts 27W, now my 16 cell Headway pack is 48volts so would be too much for it, couldn't I just add a negative wire to the negative on the first cell and the positive wire to the positive on the last cell on my main battery pack.

Would that be safe enough?
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Re: Idea for lights, no dc dc convertor needed.

Post by NorCalTuna » Sep 08 2010 4:58am

that will work, however, it will drain that group of cells at an uneven rate relative to the rest of the pack.

you could call that an "unbalancer" if you like, as that's exactly what it will do, unbalance a chunk of your pack at 2 amps.

DC-DCs aren't expensive, especially 27w 48v ones. Come on, do it riiiiight....

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Re: Idea for lights, no dc dc convertor needed.

Post by Spacey » Sep 08 2010 8:12am

Good point ....cheers for that :)
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Re: Idea for lights, no dc dc convertor needed.

Post by ebent » Sep 08 2010 9:00am

If you intend to power additional accessories you might want to add a power strip that would recieve 12v from your converter. From there it will power all 12v items. It is really nice to be free of aa and aaa bateries. Besides the expense, they always run out when you need them the most.
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LI-ghtcycle   1.21 GW

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Re: Idea for lights, no dc dc convertor needed.

Post by LI-ghtcycle » Sep 08 2010 11:39pm

Maybe this isn't a good idea, but what about paralleling the 12V sections and running all your 12V needs from that? Would that be a problem while at the same time the motor is drawing 48V?
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Re: Idea for lights, no dc dc convertor needed.

Post by AussieRider » Sep 10 2010 7:06pm

G'day folks
Mate, you can't put your batteries in series for 48V AND in parallel for 12V at the same time Try drawing the wiring diagram & count how many shorts you have.
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Re: Idea for lights, no dc dc convertor needed.

Post by LI-ghtcycle » Sep 11 2010 9:51am

Ahhh yes, I knew there was something that would stop that from working he he.
Thank you Justin_Le for your selfless act of kindness! We all are in your debt.
Back on track E-Bronco! Now with Cro Motor Mid-Drive Goodness!
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Vision R40 w/3000w MXUS as mid-drive, NuVinci N171B rear wheel as transmission, Silent yet powerful, running 72v 11.6 ah (20s 18650 Li-Ion) to climb hills, tow trailer with zero pedaling when needed!

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heroic   10 µW

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Re: Idea for lights, no dc dc convertor needed.

Post by heroic » Sep 13 2010 6:37am

I have one of these:
http://www.amazon.com/gp/product/B001TQ ... ss_product

It's ungodly bright (seriously: brighter than most motorcycle headlights), mounts nicely on my handlebars, and works on 9 to 60 volts. I have a dc-dc converter on my bike anyway, because I have a Stirling fridge that fits nicely in my trailer for those trips to the park, but it's nice to know I can run it straight.

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Re: Idea for lights, no dc dc convertor needed.

Post by Jay64 » Sep 13 2010 10:15am

If price is an issue, Fechter pointed this out a long time ago, you can use a lot of your laptop/printer/etc power supplies as a dc/dc converter. A lot of them will run off <110v (some don't so you have to check the ones you have.) But I'm sure a lot of you have some extra ones just laying around from past equipment, I know I had a bunch and I tested them out on a 48v test pack that I setup. The output on them also ranges from unit to unit, so check that also, but they are free, so you can't really beat that. Just thought I would throw that back out there.
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Re: Idea for lights, no dc dc convertor needed.

Post by amberwolf » Sep 14 2010 2:12am

Yep--check out my CFL headlight/taillight thread in my signature--I use an Averatec 19V laptop supply to *increase* my total voltage to run some CFL lights. :) But it could be used separately, too. I also used some celphone chargers the same way.

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