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Re: Best battery

PostPosted: May 20th 2020, 5:49am
by Rod's Trucks
Yup! I'm with MM on this issue.
You have done a good job tracking things down.
IMO, you are on the high end of the normal range. With that high output alternator, that may be the best you can do, but I think you have made great progress and should be able to maintain it at that level.

My factory voltmeter jumps and bounces around, and reads a bit higher than a meter at the battery, so it is just a reference point. Like the oil pressure gauge, I have no idea exactly what the oil pressure is, but I know where the gauge reads 'normally', and that is my reference. My battery charging voltage is about 1/2 volt higher than I would like to see ( at 14.6V ) , but until I get a few other items taken care of, it will do. I seldom goes on long trips, so the battery is not charging at that voltage for hours, like it might on a cross country trip.

If you have checked for voltage drops and cleaned all the cable connections from alternator output to battery, from battery to ground, from frame ground back to the engine block, and back to the alternator frame, there is not much more you can do.
If the voltage drop from the alternator output post to the battery positive terminal is low, that is good. Then look at the some situation on the ground side ( Alternator frame to battery negative post). Hopefully you will not find any problem there either, but if you find much voltage drop, go back to each connection point and measure across that connection. All should be withing about 10% of the same voltage drop. I am talking about the alternator charging currents and voltage drops under 'normal' operating conditions. If you find one that seems to be high, investigate why.
Typically, good connections will not drop more than 0.1 volt, except under high current loads, like the starter motor ( or your winch under a heavy load); and even then you do not want much more voltage drop. Voltage drop generates heat, which melts things if it does not get dissipated quickly.
Rod J

Re: Best battery

PostPosted: June 3rd 2020, 1:51am
by markmitch
When I went bigger on the battery cables and the wires going from the starter to the alternator I replaced the bolt in the sheet metal then ran a cable from the block to the frame and my replaced 105 amp alternator seemed to gain. Engine starts on first turn of the key any time no matter what te outside temps are. I also went to the largest battery I could fit in the stock location.780 cca's