221Views8Replies

Author Options:

Is there a simple way to power both 6 and 12 volt devices from a 12 volt battery? Answered

I wired up my bicycle with a 12 volt battery.  The problem is, I have a Cree MC-E led which requires between 5 and 10 volts with a buckpuck.  One person suggested resistors to drop twelve volts to nine but that would waste too much electricity.  Is there a simple way to cut the voltage in half to six volts which would not loose power in the conversion process.   Cutting the power to 6 volts would be best because there are devices aside from the light requiring 6 volts which I want to install. 

8 Replies

user
steveastroukBest Answer (author)2010-10-04

What kind of battery, and are you prepared to commit a violence on it....?

Steve

Select as Best AnswerUndo Best Answer

user
Noblenutria (author)steveastrouk2010-10-04

Its a 5 amp/hour sla. Those batteries are dirt cheap. I could do some damage to it.

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)Noblenutria2010-10-05

USUALLY, you'll see some oval bits on the top of the battery, NOT on the centre line of the cell. These cover the connections between the individual cells in the battery. Use a dremel to expose the one between the 3rd and 4th cell: there will be six volts on it.

Its a BAD idea to assymetrically load the battery, so don't use the 6 V side exclusively, or arrange TWO loads, one from battery min to the tapping, one from the tapping to battery +.

If you CUT the link, you could be even cleverer, and make it work as a double capacity 6V cell.

Steve

Select as Best AnswerUndo Best Answer

user
coolpizzadude (author)2010-10-04

I don't think that there's any way to drop the voltage without some sacrifice. I would reccomend useing a voltage regulator instead of resistors though.

Select as Best AnswerUndo Best Answer

user

Do you think this would work http://cgi.ebay.com/ebaymotors/12-Volt-6-Volt-Heater-Blower-Motor-Voltage-Reducer-_W0QQcmdZViewItemQQhashZitem4cf23ddab6QQitemZ330481654454QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories#ht_500wt_956

Select as Best AnswerUndo Best Answer

user

Yes I believe that will work. But it looks like a resistor to me. I thought you wanted to drop the voltage another way?

Select as Best AnswerUndo Best Answer

user
blkhawk (author)2010-10-05

What about stepping down with some kind of transformer? I do not know where to start but , you would lower voltage and increase amperage.

Select as Best AnswerUndo Best Answer

user
frollard (author)2010-10-04

Get a 'better' buck that supports 12 volts? most efficient option as converting down to 6 and then to 'whatever led voltage' is more work than necessary.

Select as Best AnswerUndo Best Answer