Rectifier Out

[MAJ1966]

I have a 125 mariner (1998) on my tourney pro and been having an issue with the starting battery going dead. I always turn off the battery so if something is left on, it won't drain the battery. So I did a little trouble shooting and notice that I get a spark when I touch the motor leads to the battery, telling me there is a load on it, so long story short, the rectifier is out or on its way out. I have heard that on board chargers can cause them to burn out? I have a 3 bank Dual Pro charger that has been on the boatfor about 4 or so years. I had a 2 bank previously, but that only charged the trolling motor batteries.
Any truth to the charger taken out the rectifier?

[yarcraft91]

The charger will not take out a rectifier unless the charger is faulty- even then, it's unlikely. Rectifiers don't last forever- I've replaced them twice in my 1991 motor. The first one lasted 9 years during which I never used an on-board battery charger. The second lasted 9 years and I used an on-board charger most of that time. One thing that can kill rectifiers is a near-dead battery that constantly draws a high charging current.

If you're worried about the charger- check the voltage at the batteries when the charger is operating. At steady state of charge, the battery voltage should be 13.2 Volts, during the charge cycle may go as high as 15, all normal and the rectifiers are designed to handle voltages in this range.

The spark you see when connecting a lead to the battery may be temporary charging of a capacitor, not a steady current drain- very common. Can you put a current meter in-line between the battery and the lead to see if there is a steady current drain?

[MAJ1966]

Well thats what I thought, but somewhere I had heard that they (chargers) can mess with things in the motor??
I ordered a rectifier yesterday and should be here today. When I was "testing" the motors elasd for sparks, I first unhooked both red wires from the rectifier, no spark from motor leads, I then hooked up one red lead, still no spark, hooked up the second red lead, spark. I will also put a meter to it tonight and see what I get for any drain.

[yarcraft91]

You could mis-connect an old-style battery charger and damage the motor charging system, but it's pretty unlikely with the modern solid-state, regulated, computer-controlled chargers- not impossible, but the on-board chargers are intended for long-term connection to the batteries, including float charging all winter.

Good luck with the repairs.

[Bill Krejca]

Back when Sue from Guest was a steady help to many of us on WC, I asked her about the spark I got when re-hooking up my battery wiring. She said a spark was to be expected , as the charger (in my words) "had a capacitor effect", which resulted in a spark, not to worry. I have learned to expect a spark now, whenever I reconnect my cables.

Bill Krejca

[VernH]

If you have a main battery disconnect switch, turning it to off before the motor stops running can trash the rectifier too.

Look at pictures of Perko switches as an example.


Vern

[MAJ1966]

well we are fixed i hope, we'll see if I still have battery drain with the new rectifier. As of now I have 13 volts at the battery according to my volt meter, will start to reconnect my wiring to the battery.

[MAJ1966]

well I thought my problems were fixed. Guess not, went to hook up the starting battery to the on board charger and now I get a red flashing light for that battery? I emailed dual pro and was told that the battery was dead and need to be charged with a standrad battery charger, I did that, checked the battery and had 13 volts, had it checked out by our local interstae battery supllier and they said it was good. But I still get the red flashing light. Anyone have heard of this or even have the same problem?
Told the wife. thats it I need a new boat.........