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running out of electricity

jvandyke

Luke Skywalker
Offline
I notice that when I run at night (with lights on) (seldom) my volt meter is sub 12v. Am I right that this would spell trouble if I were to run for an extended period like that? The original generator isn't keeping up? Without the lights on and rpms at normal cruise it's showing 14ish. Not a big worry really, but I'd hate to be running at night sometime to find out I'm draining it all down to nil. I do have an electric fan (which is seldom on) and a stereo (puny no amp, little draw). If I turn off the stereo the volt meter needle doesn't move, turning off the headlights though, it goes up quite a bit.
 
Halogen headlamps ? if they are they do draw more than stock units . Also if you are running halogen with out a relay setup your going to be probley drawing more amps and dimmer lamps If you need a relay setup the quickest easy one I have found is sold by VIC BRIT they have units prewired with lamp plugs for like 25? dollars maybe less. If your going to drive at night you need to get this setup or at least something simular it could save you lamp switch and harness at the least and possibly your car from a fire.
 
I feel a bit stupid(er) but yes, I believe halogen, one piece. I did wire in relays for high/low so they draw straight off the battery. It isn't a problem (yet) but I'd hate to find out it is 100 miles from home in the dark.
 
It is the nature of the beast.
The volts will run out after 3 hours of night driving with halogens, and a radio on. And I was exactly 3 hours from home and the Bugeye died in the driveway.
It happened to me twice before I converted to an alternator.
 
I upgraded my old Opel GT because it was "only" 43 amps (or something) I put one of those Chevy ones, 103 amps I believe. Two weeks later....smack.
ouch.JPG


I could not get the alternator off the car the front was smushed so badly. I still have the original Opel generator sitting under my workbench....hmmmmmm. I don't think you can put German parts on a British car, something wrong about that.
 
You have discovered one of the main reasons for doing an alternator conversion: the Spridget generator is only 20 amps, and will put out that much only above about 1800 RPM. It just barely handles the electrical load, at best. If the battery were in good condition and well charged, you could get several hours of operation at full load, maybe a whole night of running with lights on. But the weak generator and that hopeless mechanical regulator don't do a good job of keeping the battery properly charged.

I wouldn't trust the standard system for more than a couple hours of night driving, unless you're going fast enough that the engine is consistently above about 2000 RPM. Idling with the lights on, you're pulling around 10 amps beyond what the generator can provide, and that extra current is coming from the battery.
 
I guess it was good that I put the voltmeter in and paid attention to it a bit. At least I know I have limited night driving now. Glad to know it before I plan an all night run.
 
histerical said:
" I was exactly 3 hours from home and the Bugeye died in the driveway."
How far is your house from your driveway ?
:lol: you owe me a keyboard. reminds me of the guy who read that most accidents happen within three miles of home - so he moved.
 
I experimented a bit today. Lights on certainly lowers the volt meter a bit but the heater motor drops it even farther the the lights, stereo has no discernable effect (assuming it doesn't draw when off), but at a steady cruise it was still hovering pretty darn close to 12. I'll play more tonight, heading home from work in the dark. Of course, if the cheapey meter is off a tad either way it would make a difference. Maintaining 12.1 might be sufficient whereas 11.5 may not.
 
You might also consider that the Regulator is not set correctly.
 
Yes, that's an important point--whatever you do, make sure that the regulator is working right. That's essential for the battery to stay charged, at least as well as it can be. Also, all the usual things--make sure that connections are tight and uncorroded, and so on.
 
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