Potential solution to Aux Power issues.

[stretchman]

I remember when I was a kid a friends dad used a standard 110v light bulb to reduce voltage so he could trickle charge his motorcycle batt Not sure how it went to dc volts????
I agree with Scottyb draw up a schematic.

What if you used LED's

[bacord]

I have no ideal if any of this is posable, his original post just got me thinking. The adding a 12 volt battery was more to add range without going to 48volt. Like I said I have no clue but know a VERY little about Ohm's law (from school 25 years ago). Thanks for the info about the lights. So I would hook up the + from the light switch to + wire on first lamp then the - of first lamp to + wire on 2nd lamp. Then come off lamp #2 - to + on last lamp then - from # 3 lamp to - at end of battery pack.

[JohnnieB]

Originally Posted by scottyb

This is a very interesting discussion, any kind of drawing would greatly help everyone follow along ....

Download Google sketchup7 or any simple free drawing program if you have none.

This is the best I can do at the moment.

Note: "BL+" and "BL-" being the the terminals on the cart's 36v battery pack that are connected to the controller and "--" is an interconnecting wire.

Two 12v bulbs and a 12v battery in series: (BL+)--(12v Bulb)--(12v Bulb)--(12v Battery)--(BL-)

Three 12v bulbs in series: (BL+)--(12v Bulb)--(12v Bulb)--(12v Bulb)--(BL-)

I no longer have access to a CAD program, so I'll have to pick-up a schematic drawing program of some-kind rather than subjecting the forum to my hand drawn abominations, but can't do it right away.

We're leaving in the morning to visit some kids and g-kids in MI over the 4th and SWMBO is giving me the evil-eye, so I had better get busy on my Honey-Do list.

Thanks for the possible drawing program tips,
John

[JohnnieB]

Originally Posted by stretchman

......
What if you used LED's

They might work, but not the same as light bulbs, and you'd need a bunch of them.

Basically a LED is a low voltage Ziener Diode whose PN Junction happens to emit monochromatic light and the voltage drop across it remains constant as current flow through it varies. Therefore, you'd be applying a constant voltage to the battery rather than a constant current. And you wouldn't be a putting much current through the battery since LEDs don't pass much current when compared to light bulbs.

Now I'm really getting the evil-eye!!!

[bacord]

bump

[Kix]

In in the instance you describe of adding an aux. 12v battery to a 36v pack using 2 12v bulbs............what happens if one of the bulbs breaks or burns out?

[yurtle]

Here's how I did it:

http://www.buggiesgonewild.com/membe...hen-tuner.html

http://www.buggiesgonewild.com/membe...use-block.html

[crash12888]

Originally Posted by Kix

In in the instance you describe of adding an aux. 12v battery to a 36v pack using 2 12v bulbs............what happens if one of the bulbs breaks or burns out?

It opens the circuit and stops working beacuse it also acts as a fuse.

I mentioned the 2 headlight and 2 tail lights in series years ago when people were looking for alternatives to adding lights to electric carts without the expense of a reducer or tapping just two batteries.
The principle is correct.

Remember the cars that had 4 headlights? car ran a 12 volt system but the headlights were 6 volt each.
Good thread to read.