alternator sence wire

[scratcher]

many years ago I fitted a diode inline with what I remember as the voltage sence wire to trick the alternator into upping the voltage to the batteries.It was on a volvo 18 hp 2 cylinder.The .6 v drop accross the diode increased the output from approx 13.9 to 14.4 as I remember and did shake some life out some oldish batteries.Any alternator experts want to chime in as I want to repeat this

[atoll]

not sure if a diode would do anything,i think you mean a resistor

[btrayfors]

Originally Posted by scratcher

many years ago I fitted a diode inline with what I remember as the voltage sence wire to trick the alternator into upping the voltage to the batteries.It was on a volvo 18 hp 2 cylinder.The .6 v drop accross the diode increased the output from approx 13.9 to 14.4 as I remember and did shake some life out some oldish batteries.Any alternator experts want to chime in as I want to repeat this

That should work fine, but check the alternators output closely.

Note that 13.9VDC is too low for effective battery charging. And, 14.4VDC is also too low for most flooded lead-acid batteries (Trojan recommends 14.8VDC to 15.0VDC for their T-105s).

Bill

[SteveSails]

In theory it will work but a silicon diode needs a few milliamps (.001Amp) of current through it to drop .6 - .7V. The voltage sense circuit in the regulator may not draw that much and you may only see half that drop. But you may not need the diode, external regulators like the Balmars are programmable and you should be able to set the charge voltage without any extra 'tricks'.

[Stu Jackson]

Why not just run the sense wire to where it should be: the house bank.