Battery / charger problem

[ArtJ]

In the spring I upgraded my Battery and charging system to be able to
run a small refrigerator.
The system consists of 2 group 27 deep cycle batteries which are connected
to a a/b/ both switch, then the electrical distribution system. This was
the existing circuit.

I have added a second bank consisting of 2 golf cart batteries connected
in series, followed by a second a/b switch, which I have blocked so that
only A position and off are available, since it is really only one battery.
The outputs of all batteries are tied together so that any combination
of batteries can be selected.

I have also added a 130 amp alternator that I purchased from Indigio, as
well as a Xantrex 3 stage smart regulator. ( the regulator I have limited
to 40 amps for now.

When all switches are off, the only thing that is left in the ckt is a
Flagship marine alarm system which is wired directly to one of the
batteries.

There is also a 7 seas digital ammeter with shunt connected just
after the 2 a/b switches. As well there is a analog %charge meter
/ voltmeter also after the a/b switches.

I have also installed a snubber in the alternator ckt, additionally,
the xantrex regulator is fused and there are 2 external warning leds
for the xantrex in case of problems they would lite.
Upon leaving the boat I normally switch both a/b's to off and arm the
alarm system (also new).

Several people have told me that they have seen red lights on in the
cabin at night recently, but I dismissed this as reflections from the solar
powered cockpit spotlight.

I made a brief 3 day trip to cape cod this weekend to try out the
refrigerator.

Everything seemed to go fine. The refrig initially drew 7 or 8 amps,
then settled down to less than 2 amps. We motored about 4 hrs
per day. and I ran the engine for around 1/2 hr at anchor until
the ammeter showed only a few amps charge rate.

The trip ended a week ago.

Yesterday, I was down for a sail and was running the engine checking
for coolant leak. I noticed that the percent charge was not pegged as
it usually is, but instead was reading a steady 50 percent charged or half scale.
Not sure about the 50 percent, because there is also a a scale for other
types of batteries, but the meter was definitely at half scale.
Although, earlier in the day I monitored the digital ammeter and it
was charging. The batteries being used were the golf cart bank.

When I got back to the mooring and stopped the engine, shut off
both a/b switches, but noticed that the VHS Radio's separate
rocker switch was still lit. This astonished me because there was
no apparent source of power since all a/b's were off.

I flicked the a/b switches, several times with no effect. The VHS
rocker switch remained lit and the analog meter read 50 percent.

I turned back on the digital ammeter to look for current draw or power
and saw none.

The only way I could stop the voltage reading and rocker switch
being lit was to turn the vhs radio switch off, the Battery monitor
then read zero volts, and the vhs rocker became unlit.

There may be two separate issues here, or they may be related
As I mentioned above, people have told me that they saw the
red light from the cabin at night, but I dismissed it as relections.

I am wondering if there is some parasitic path that is allowing the
battery to show voltage,though low. The only thing that has
power with the switches off is the alarm system.

Any thoughts or suggestions appreciated.

Thanks

Art

[ArtJ]

I forgot to mention, I have also added a temperature monitor sensor to
the Xantrex regulator, but if this shutdown the regulator, one of the
warning leds would have been lit, they are not.

I am wondering if I have a disconnected ground wire somewhere?

[ArtJ]

Things I have thought about to check:

1. the obvious, grounds,
2. a/ b switches themselves.
3. the snubber bad? I normally, when switching banks while running the
engine, turn on second bank before switches off first.
4?

[ndutton]

An accurate wiring diagram would be of immense help, both for you and us.

In the absence of same, here are a few initial thoughts:

Have you determined the source of the red light? You spoke of the VHS (did you mean VHF?) radio rocker switch remaining lit with the battery switches off, is that the red light?

You need to be certain where the VHF power comes from. Your description suggests rather strongly that it is connected ahead of the battery switches even though you believe it isn't.

While you're at it, look for some wiring relationship between the alarm (does it have any red lights?) and the VHF. Starting down the path of a possible lost ground, does shutting down the VHF have any effect on the alarm system? Or anything else?

It's possible there's a lost ground somewhere and the ground path is finding its way through the VHF although I think this is unlikely because usually such backfeeds act like poltergeists and you report no such symptoms.

Then finally, can't really comment on the 50% charge reading without the diagram, too many variables.

And what's a snubber?

[ArtJ]

An accurate wiring diagram would be of immense help, both for you and us.

In the absence of same, here are a few initial thoughts:

Have you determined the source of the red light? You spoke of the VHS (did you mean VHF?) radio rocker switch remaining lit with the battery switches off, is that the red light?

You need to be certain where the VHF power comes from. Your description suggests rather strongly that it is connected ahead of the battery switches even though you believe it isn't.

While you're at it, look for some wiring relationship between the alarm (does it have any red lights?) and the VHF. Starting down the path of a possible lost ground, does shutting down the VHF have any effect on the alarm system? Or anything else?

It's possible there's a lost ground somewhere and the ground path is finding its way through the VHF although I think this is unlikely because usually such backfeeds act like poltergeists and you report no such symptoms.

Then finally, can't really comment on the 50% charge reading without the diagram, too many variables.

And what's a snubber?

A snubber is spike suppression diode, the one I have came from Balmar.
It's purpose is to protect the alternator diodes from transients.

I did mean the VHF radio, but may be other ckts which can be on as well.
All instruments, VHF radio and Analog voltmeter have been in the boat
for years with no problems. They are after the original a/b switch

[ndutton]

A snubber is spike suppression diode, the one I have came from Balmar.
It's purpose is to protect the alternator diodes from transients.

Thanks for the explanation. To stray off topic slightly, what transients or spikes are you trying to protect yourself from? My charging system isn't nearly as sophisticated as yours, real old skool meat and potatoes stuff, and to my knowledge I've never suffered any damage or even symptoms of such transients.

All instruments, VHF radio and Analog voltmeter have been in the boat
for years with no problems.

OK, so what's different than before? That should be a clear indication where the problem is.

[ArtJ]

Thanks for the info Neil.

I don't have visio on my pc and not sure how to post a wiring diagram.
I could draw up a pencil version and fax it .

The system has been installed for several months and I didn't notice any
problems. The alarm system is the newest thing.]

I also never tried out the ckt for refrig previously, but it worked fine on the
trip. I am wondering if I knocked a wire loose, I think I noticed a loose one
near the switch a couple of days ago.
I am going down today and do some troubleshooting.
will advise of findings

Thanks and Regards

Art

[ArtJ]

Update on Battery Chargers

I relocated the alarm system so that it follows the same power, gnd
paths as the other circuits. I.E. it is powered thru the a/b switches via the
usual path and then thru a subpanel like everthing else.

It appears to have solved the problem, at least with the percent charge
voltmeter, as it now reads fully charged.

I will keep monitoring however before pronouncing it 100 percent fixed.

Regards

Art