6v dc to dc converter/booster on Bafang BBSHD 6v wire

[Olddog]

I would like a decent light. The one I have does not produce enough light. 6v 3w only. Many 12v options are available and some very small Dc to DC power converters are available also. The wire I have produces 6v .5a (3w max right?) when the display is on night mode without motor running so I suspect it is wired direct to cells of my 48v 11.5 ah battery. My question is.....If I connect a Dc to Dc converter to the wires I have, to increase voltage and/or amps, will the Battery Cells connected to my wires discharge faster to the point the BMS shuts the power down because of cell balance?

[max_volt]

I don't believe there is a contraption that will output more energy than is going in. It's a curious cable with an output more in line with USB. I have 4v and 8v bike lights that won't function properly straight from it. I was thinking of using it to drive a relay that would connect a 48v light to the battery voltage.

[JPLabs]

First Law of Thermodynamics agrees!

Olddog, it can't pull any more than that 3W, no matter the output voltage. So won't affect cell discharge rate if you use a converter.

If it's really just running off one cell as you suspect, though, then the more you use it, the more you will unbalance the pack, as you suggested.

[ykick]

Seriously doubt it’s pulling power from a single cell group. The fact it’s switched from dash/display night mode infers it’s a simple power supply tap from the motor controller providing switched 6V/0.5A=3W. If you were to add DC-to-DC step up convertor divide 3W by 12VDC = 0.25A is all that can be drawn from the 6V circuit. By the time you account for losses converting 6VDC to 12VDC you might be lucky to see 2W at your 12V light?

IMO, those 6VDC switched lighting outputs are simply waste of our time. Typical Chinese marketing at work. They tend to add things that nobody really needs or wants because they want to charge more to resellers the next time they order a batch of products.

If you want to power 12VDC automotive/marine accessories a good bet is Golf Cart type DC-to-DC convertors. Or, many DC-to-DC offerings accept wide input voltage ranges.

But don’t try to power anything significant from that 6V/0.5A switched output? Maybe a small relay if you’re really in love with the dashboard switching lights ON/OFF?

[Olddog]

Thanks all. Your opinions matter. I am going to ditch the idea and get a good usb rechargeable light. Recommendations? Also, Do you think the USB output power on the DPC-14 comes from the battery or a power tap from the motor controller? Any lights work while being recharged on the DPC-14?
Thanks again.