could some one double check my figures ?

thegnu

thegnu

New Member
Just a quick question, I have been really working hard on designing the electrical system on my build , an just wanted a outside opinion to kind of confirm if I am correct or if I have it flawed ( I'm decent with electrical but some of it is still a mystery to me) ....so heres the particulars.
I want to use this setup any one see any possible problems ?
12 volt 7.5 amp hr sla battery-being charged by the white wire with this rectifier at thread http://motorbicycling.com/f50/step-step-diy-rectifier-instructions-32246.html with a diode to keep current from flowing back to the motor.
now at the actual lights ...
2 x led driving lights 156 ma
4x 194 led 30 ma
2 x 1157 led 75 ma
to my calculations at no time would I theoretically be drawing more than 600 ma ..... am I correct an is this a viable lighting system other wise I redesign.

thanks for looking.
Gary
 
You design should work fine.
With a 7.5 A/hr battery, you can go a while before needing a recharge.
 
thats why I want to add the rectifier to recover some of the electric from the mag an further extend the needed recharge because , I will have the headlamps an tail lamps on full time for obvious safty reasons , you know people miss motorcycles an these bikes are even smaller .
 
Your total current draw is 582 mA, and I think that the magneto is hard pressed to deliver even 500 mA, so you will be operating at a loss.
Maybe a solar charger can be put to use to help replenish the battery during the day when you are at work/school/whatever.
 
ok there is a problem ..... even if I were able to input the current from the white wire through the rectifier an diode then to that battery I have wouldnt I be able to just extend its obvious recharge , I honestly cant see riding with the lights on for over 3 hours ever , an if possible when would it become a heavy draw an kill the motor ? its seeming like my best option would be to just run with out attempting to recharge that battery by not using the white wire at all .
an thank you for double checking me here
 
It seems to me that there are several threads regarding recharge of a battery system via the white wire- in theory, it should be possible. As it stands right now, nobody has done it. There are several advantages to a 12 volt system, not the least of which is the avaliability of 1156 and 1157 compatable LED bulbs... a bit spendy, but not as bad as some systems I've encountered. The sockets for these bulbs are redily avaliable as well, and housing is left to the imagination of the builder (BWAHAHAHAHA!!!!)... however, I am to understand that the white wire will not have the poop to charge a 12 volt battery regardless of how you rig it. Mind you, I do not have an Electronics Engineer degree to verify this, but several members here and the other forum agree on that point.
Therefore a 6 volt LED light system would be the weapon of choice to start as a platform for a recharging battery operation if you MUST utilize the white wire- at least, that's what I am hearing from several corners. To me, that can be developed independantly of said charger without too much issue... and might well hold it's own weight without said charger. Run the contraption off four 'D' rechargables and get a recharger for them. You invest in two sets, one charging while the others are in use. If you REALLY do long distance at night, get three sets so you have a spare set go with you just in case.
THEN... there comes the day when somebody who is quite brilliant (or bloody lucky) creates the perfect charging solution useing the wretched white wire. Your 6v system will likely be compatable with it. Magneto tops the battery, battery pushes the lights- what could be more simple? Untill then, the regimen I have described will suffice nicely.
BTW- currently working on cable-actuated switches for brakelights. Will let you know if there's a breakthrough.
the Old Sgt.usflg
 
Oddly enough, most LEDS I find are 3 to 3.6, 3.4 to 3.8 or 4 volt- I suppose there's a reason for this, but I have yet to figure it out. I am looking to create a headlight/taillight/brakelight/turn signal system running off of one power source and am having problems understanding some things. It seems, if I want to do the 'D' battery thing, I need 2 batteries for three volts or 8 for 12volts and use automotive 1156 & 1157 LED equivilants- the latter is more price and weight but much more predictable and easier to engineer. The former will be a sharp learning curve I suspect, but will result in a cheaper and lighter system. PVC endcaps make lovely light housings and are cheap and light- Fusion paint works well with them. They also come in a multitude of sizes. A three light gang rig for-and-aft seems a reliable configuration to this end- mount on the nut that tags the handlebar to the gooseneck with a metal repair strap bent to shape (Or to the front caliper brake mount) for the headlight, similar for the taillight for rear fender or backrack. Five componants total- headlight, taillight, brake light switch, battery pack and control switches- I'll bet it could be done asa generic operation to fit most if not all bikes... just a thought...
the Old Sgt.usflg
 

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Decided to dive into my electrical charging system this eve . an measured my white wire output at idle , it fluctuated around 1.5 volts after going through the rectifier I built , that is if I was reading my meter correctly .
first test removed the battery an connected directly to the positive terminal in the wiring harness tail lights brakelights an turn sigs worked perfectly altho a bit dim .
turned on one hdlamp at a time did not get but the 1 on an was so dim it would be useless .
reinstalled the battery an left the rectifier in the system , its charging the battery very slowly but charging .
I was searching around an cant remember where I found it but isnt there something that can ramp up available current ?
 
hey gnu, yes there is, but only if its dc, which it is if your using a rectifier.
its called a dc to dc converter. what you lose when you step up the current is amps which isnt terrible for a unit of the size we speak of. look it up on ebay.zpt
 
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