Electrical Limitations

[SPYDERLK]

Get one of those cheapy gauges that clamp around your battery cable. Youll be able to see whether current is going out or in under all load conditions.
larry

 

[Soundguy]

Sir
I was trying to explain a simple approach to current calcuations without getting to deep. I was also trying to show how you do not need all the fancy meters, simple math will do. As the gentlemens inquiry was not specific as to the exact load I suggested a general overview. Short term current can exceed the rating of the alternator but if the draw exceeds time and current it will burn out or over current trip out will happen.
Every lamp has the wattage printed on the back, so if you add them all up that will be the total watts. As lamp load will be steady for maybe hours ( current consumed must = current generated ) or as you stated you will slowly drain the battery and over load the alternator.
Craig Clayton

misses part of the picture.

just adding up incandescent loads does not account for anything under the hood or in the cab that might be taking power. depending on the tractor.. you might see a decent electrical load in a cabbed/ac laden tractor.

calcs are good for fast estimation.. amperage gauge don't lie...

soundguy

 

[OldGeezerWNC]

One thing I've done over the years is to add a second small battery in parallel to the circuit. Years ago I'd keep a float charger hooked up to it with a quick connect in the barn. I have a Lincoln MK VIII and run the MSD 6l Hi Imp. ignition system and added a second battery ( MSD likes VOLTS ) a young pup told me the new solar trickle chargers worked a whole lot better. So I have one in the back window. (Batts are in trunk for weight.) I added a solar charger to my tractor on the roof of the sun shade. Keeps both batteries happy. I have added good lights, 4 clearance lights as parking lights, I hooked up my XM radio with speakers, two accessory outlets ( cigar lighters ) and one 400w inverter. I'll drive down to the mail box about 400 yards away and plug a 10 foot, 12 gauge drop cord into the inverter and use my electric weed eater for 10-15 mins to clear around it. Never have a problem restarting. Wife uses a cpap machine and last year during the blizzard of '09, I pulled the tractor under the bedroom window and she was able to plug into the inverter to keep her machine going for 2 nights when the power was out. Whoa... wrote a book. Sorry, try a dual battery system. works great for me. There that was simpler. Rick

 

[Soundguy]

series battery? as in 24v with the lesser of the 2 battery current capacities ( and hard ont he smaller battery )..... or did you mean a parallel battery? still 12v, but with the current capacity of both batteries added.

soundguy

 

[TWD]

One thing I've done over the years is to add a second small battery in series to the circuit. Years ago I'd keep a float charger hooked up to it with a quick connect in the barn. I have a Lincoln MK VIII and run the MSD 6l Hi Imp. ignition system and added a second battery ( MSD likes VOLTS ) a young pup told me the new solar trickle chargers worked a whole lot better. So I have one in the back window. (Batts are in trunk for weight.) I added a solar charger to my tractor on the roof of the sun shade. Keeps both batteries happy. I have added good lights, 4 clearance lights as parking lights, I hooked up my XM radio with speakers, two accessory outlets ( cigar lighters ) and one 400w inverter. I'll drive down to the mail box about 400 yards away and plug a 10 foot, 12 gauge drop cord into the inverter and use my electric weed eater for 10-15 mins to clear around it. Never have a problem restarting. Wife uses a cpap machine and last year during the blizzard of '09, I pulled the tractor under the bedroom window and she was able to plug into the inverter to keep her machine going for 2 nights when the power was out. Whoa... wrote a book. Sorry, try a dual battery system. works great for me. There that was simpler. Rick

Good call on the solar charger! I got one for my truck when both batteries were dieing, and it let me limp-along for another few months before replacing them :thumbsup: Dual Batteries, and an Inverter will be added in the future probably too

 

[fish6942]

I believe the output rating listed for an alternator is at max rated RPM. The amperage output will drop quite a bit as engine RPM drops. In other words, don't load up the accessories based on max output then expect them to all work at max capacity when the engine is at idle.

 

[Soundguy]

If we were talking DC generator.. that would be spot on.. however on an alternator.. they are quite a bit more efficient and don't have to be at max rpm to put out max rated power.

soundguy