Lofrans Tigres Low Voltage

[moseriw]

Ideas please! I ran out of them.


Battery 12V 225 Ah 08/2016

Motor 1500W


Voltage on Engine Battery 12,9V
Wiring: 40 ft. = 12m AWG 0 = 50 mm²



Voltage before solenoid 12,6V
down 10,5 V
up 8,7 V


calculation says 12m 50 mm² = LOSS 1V
I measured 0,3 V


Facts:

New motor 2016
New wires 2016
New Solenoid 08/2018



Test was made with Engine batt 225Ah
and with the combinastion of banks = 4x225Ah



Where does the loss come from?
And Why do I have different volts up/down?


Thank you all.

[moseriw]

Yes I know... A Battery in the bow only for the windlass.
BUT unfortunately - this is not an option.

[Ostinato]

It is the right size wire for the run. I assume you have it in both directions. What kind of performance are you getting out the Lafrans? Is the low voltage reading under load? What are the readings with the house bank only?

[SVTatia]

Originally Posted by moseriw

...

Voltage on Engine Battery 12,9V
Wiring: 40 ft. = 12m AWG 0 = 50 mm²

...

Not an expert but will be watching.
Question - 47ft boat - why is the wire run 40ft? Shouldn't it be a round trip of 80 feet?

[Jammer]

Originally Posted by moseriw

Where does the loss come from?

You will have to measure.


Get 50 feet of insulated wire, attach it to one of the probes on your handheld volt meter. Attach the other end of the wire to the - battery terminal (the portion that is actually part of the battery) or have a helper hold it there. Measure the voltage to various points on the - and + circuits to determine where the drop is occurring. Start at the cable portion of the - battery terminal, then probe the - wire a foot from the terminal, then do the same at the windlass end, then same thing on the + side also checking any switches or fuses and the associated terminals.

Or you can use an IR thermometer to check for hot spots on the cable after running the windlass in UP for a minute or so.


Typically this sort of thing is due to a bad terminal somewhere. Once you find it you can cut it off and crimp on a new one.

And Why do I have different volts up/down?

Because the windlass draws more amps on up.

[billknny]

Do not assume the problem is all, or even partly in the wiring, yet.

Have you measured the voltage AT THE BATTERY when the windlass is running? It certainly is NOT going to be 12.6 volts when you are drawing 100+ amps. It might easily be as low as 10 volts... or less... depending on a lot of things.

And it is more complex than that... as the battery voltage drops, the amp draw goes up because the motor continues to (more or less) pull 1500 Watts. Since heat generation is a function only of amps, not of volts, that is why motors and wiring overheat when voltage is low...

This is one of the reasons standard recommendation is to run your engine at 1500 RPM while pulling the anchor up so the alternator can help keep the voltage up.