On Sunday 27 June 2021 08:19:42 andy pugh wrote: > On Sun, 27 Jun 2021 at 12:44, fxkl47BF via Emc-users > > <emc-users@lists.sourceforge.net> wrote: > > all of my feeble calculations led me to believe that a 6.5 hp > > gasoline engine was more than enough to power a 220 amp 12 volt > > alternator. either my 6.5 hp engine is more feeble than my brain or > > my calculations are way off. > > 220A x 12V = 2.640kW = 3.5hp. So it should be able to manage it.
True Andy, but thats a pb battery and will need at least 14 volts for a decent charge level given the average bean counter at guvmnt motors reticence to allow a 4 gauge cable so the alternator is well connected. Ground ohmage thru mounting brackets etc also has to be totalled into that resistance at 220 amps. His one wire spec can be a huge problem. BTDT back in the '70's living in Nebraska, but made my own switching mode voltage regulator which removes that "minor" resistance by watching battery voltage via a direct connection to the battery. Incorporating lots a si diodes in series with a 4.7 volt zener, then scaled to adjust it, I moved that alternator and regulator and 2 batteries to the next 4 vehicles I wore out. The regulator tempcomp was from its position on the firewall, senseing battery temp from engine temp only quicker. At -25F it hit the battery with over 17 volts and 80 amps for about a minute after a cold start. But at 100F out, it was down to just over 13.3 volts, and I never in about 12 years, had to add water to either battery because it was being overcharged. Each battery has its own personality, and I could adjust the regulator to match things well within a month or or less of switching a battery with a shorted cell for a new one. > You might need to look at the pulley ratios. Do you have a performance > curve for the engine and the alternator? You need to consider the > relative torques for your chosen speed. A "salisbury" drive and clutch on the motor can scale that automatically. I had an original "Tote Goat" when I lived in the black hills near Raoid City, SD, in the 1960's. Several engines used up, generally speaking 10 mph on flat ground, 3 or 4 mph "up a pine tree", with any engine I could bolt in. I drug quite a few deer back to the truck with it over that decade. Handy as could be in rough terrain. I raised my then 3 kids on hamberger made from venison. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
