over 16VDC on 12V system

[Volkhard]

Tinkering with my Navligths I found out that the wires for the mastlights are carrying 16.65V. My anchorlight failed a couple of weeks ago and somebody is going up the mast weekend after next. In preparation for the trip I looked at the wires going into the mast and there is a nice 4-pole connector wre the wires entry the mast. At the connector I can measure 16.65 V DC!!

I only have a 12 V system and will start to investigate over the weekend to find out what might be the cause of this. Has anybody had an experience like this and can point me into the right direction. I will post my findings (after I hopefully figured out what's going on). I know we have a wealth of experience here at the sailnet and I am learning quite a lot even by just reading posts.

Thanks for all your input

[airdog07]

are you running the engine or charger on when you check the voltage, if the engine is running check the voltage regulator, if the charger is on check the charger, you need to list the equipment in order to determine more

[Omatako]

As airdog said, you're overcharging - faulty regulator or similar

[Rockter]

Your batteries will be bubbling merrily.

[noelex77]

Check the voltage with another meter, but if the voltage is 16.65 it needs fixing quickly. It will damage your batteries and some electronics connected to them (this is probably why the bulb failed)
It has to be your battery charger, wind, solar or alternator regular that is faulty.

[timebandit]

I bought a couple of $4.95 digital meters from Harbor Freight and found them to be worthless.

The one time I did find a charging system pumping out 16+ volts turned out to be a loose battery terminal conection.

[Volkhard]

Finally on the boat:
Engine off
charger (freedom 20 inverte/charger) off
shorepower disconected.
Battery switch : All

The Link 2000R shows 12.7 Volts
The built-in analog DC volt meter at the panel shows 12.6V
The Northstar M121 plotter in the cockpit shows 12.2V (usually lower)

These are the instruments and readings I am usually trust.

Measuring on every battery (Lifeline AGM 2xHouse, 1x Starter (xantrex echo), 2 in the bow (parallel for bowthruster) they all show 16.6V at the terminals. No difference whether Batterie-switch is on 1,All,2 or off.

I assume, the status of the AGM,s is overcharged to 16.6 V.

I turned on loads (lights,fridge,fans) to spill some Amps to bring eventually the Volts down. Will leave them on during s long lunch break.

I tried to activate the Freedom Inverter.Does not come on. Not remote controlled from the Link 2000R panel (although the green LED is on) nor by ushing the appropiate button directly on the Freedom(no LED lit!)

That,s where I am right now. Any recommendations where to go from here for a systematic trouble shooting?

[timebandit]

Go to your car and check the voltage on your car battery with the same meter you used on the boat.

[btrayfors]

Rick,

You and I are thinking the same thing.

The various voltage readings don't mean much UNLESS they were all taken with the same meter AND one which is calibrated. I assume you're measuring the battery voltages directly with a multimeter, and that other voltages are derived from the equipment (Link monitor, analog voltmeter, plotter).

Of these, the Link voltage, 12.7 is likely to be right. If you take your multimeter directly to the batteries and get 16 volts, I would throw the meter overside and get a good one.

Bill

[Volkhard]

Rick, Bill
You both were right. It was the meter! I brought in a cheap one and got a good reading. I than checked the 9V block in the expensive Clamp meter I used before: down to 4.5 V.
I bought this meter recently especially for the boat and expected some kind of low battery warning. After all these things measure voltage. How hard could it be to design them to give s warning if their internal circuit voltage is low?
Anyway : 9V block exchanged I am getting now a good reading same as the Link.
Again something learned: Don't take anything for granted and check the simple things first.

Now it's time to check the Inverter and figure out what's going on with the Nav lights.
Thanks for all your input.