I need help with a lighting project/upgrade that I am doing. Ive been trying to figure out what capacitor size to use without using a battery. Ive upgraded my charging system to 250w and I know I have plenty of current to continuously run the lights. The system will retain the factory 12v system. The ballasts require 4-6amp initial start up current. Its a total loss system so I have no battery for stored current. I want to use a capacitor to store the needed start up current when I turn the lights on. I dont want to add a battery due to weight and available space thus the idea of running a capacitor. Ive dealt with 1 & 2f caps in car stereo applications but think those sizes are overkill for what I need.

Id appreciate any advice I can get.

Thank you

 

Lack of info. What prevents the use of a slowblo fuse. One could easily handle the momentary surge current.

If your talking milliseconds to 1 sec., then caps are your easiest path. If it needs multiple seconds or more, then caps won't work

 

Its momentary. I just need to figure out what size cap I need to supply the initial amp to trigger the ballasts to start

 

I think If you give your title related to your Issue it will be easy for everyone to answer quickly...(For everyone)

 

A schematic would have helped understanding your startup current issue, if it is inrush current a PTC thermistor will help.

Anyways for 6amps flow of charge is 6 coulombs/sec, a 0.5 farad capacitor will pumpout that current at 12Volts

 

Well what im doing is changing my lighting system on my quad replacing the factory headlights with HID lights. Its a 2 stroke with magneto. There is no battery. I changed the factory stator to an upgraded 250w stator. I floated the ground to change from dc to ac output and replaced the regulator with a rectifier.

The only info I had found was people adding a battery which I feel is unnecessary because I wont have the lights on without the engine running.

Thank you edgetrigger. I am gonna check locally and see if I can find a cap.

I do have electeical knowledge but wasnt confidant enough to make the right choice. Is rather spend days researching or asking for advice than destroying $250 in lights.

 

This topic is not for discussion on these forums.

Excerpted from this thread: Automotive Guidelines

2. Any homemade wiring modifications to signal or head lighting, or penetrations through the fiewall are not for discussion. The lighting function is to too critical for non-approved wiring and connectors. Many safety issues are involved.

You should not attempt to modify your headlamp system. Automotive environments are among the most extreme on the planet. Any amateur modifications will be far less reliable than the original factory configuration.

 

Is this on on road or off road vehicle, and to the mods, does this matter?

 

This is for an off-road vehicle, so I think we can let it get answered. The OP should be aware that making mods to lighting can lead to unexpected failures, though. It's a hard way to find a swale or barbed wire if your lighting decides to quit.

 

Wow......didnt think I would get looked down upon for trying to figure out what size cap to run on my off road quad that I race in the desert. Its pretty dark at night running up to 80mph and I just wanted to see better.

By trade I used to work construction doing industrial elecrical. I fully understand basic electrical theories and concepts thats why after reading throught several various posts I joined. Just figured it wouldnt hurt to ask an electrical question.

 

Oh sorry, I missed the "quad" part. That seems to be a term that UK'ers use; I've only seen it mentioned once or twice on here before and I had to look it up then.

 

Its ok....just caught me off gaurd. Wish I was in daytona for the rolex 24hr race....i miss it