2007 Tomcat Owners...need help deciperhing battery selectors

matt_unique

Do you guys know if C-Dory or the dealer installs the battery selector switches?

My Tomcat has two battery selector switches and three batteries so the use of the switches is not intuitive (to me).

These are my specific questions....

1.) How do I set the switches so that when I am
anchored with the engines off I am only drawing from
the house battery?

2.) How do I set the switches to charge the batteries
when the engines are running? If I needed to charge
one battery in particular with my engines running for
example, how would I set the switches? (i.e. Just
ran the shower and stereo from the house battery and I
want to charge that battery first).

3.) Lastly, how would I set the switches to charge
the batteries when I am connected to shore power?

I realize I can sit down with an ammeter and figure this out eventually but it would be great to have an idea going into it.

Thanks!

thataway · Posted: Wed Jan 09, 2008 3:45 pm Post subject:

This is from memory, and I have changed from what the factory was initially. The charger (5/5/10) should be set up hard wired to the batteries, so when shore charging each start battery is getting max 5 amps charge and the house 10 amps.

Off, should turn the battery switch off, with no engine start or house. The starboard switch gives #1 starboard engine, #2, the output from the "all" output on the port side switch. All on the Starboard switch, combines these. Prot side battery switch gives #1 position port engine start. #2 position, is house battery. So at anchor, and using the house, Starboard switch off. Port side on #2 so that you are only using the house battery.

I have added VSR relays so that the stb engine also charges my inverter/refigeration bank, and the port engine charges the house bank.

Both engine charging circuits go to their respective batteries thru the switches. You do not want to turn the switches when running the engines.

When I leave the boat--all switches are off.

The 40 amp battery charger is wired to the two "inverter/refigeration" battteries.

Captains Cat · Posted: Wed Jan 09, 2008 5:17 pm Post subject:

drjohn71a · Posted: Wed Jan 09, 2008 6:28 pm Post subject:

From a more amatuerish source than Dr. Bob, here is my practice:

All three batteries charge from the shore charger regardless of the setting. I think all three circuits charge from the engines also. I bought a cheap, lighter insert battery tester/dial that reads out the volts in a circuit when you plug it in and the engines running seems to charge the HOUSE leg just fine.

there should be three main switches: Port Engine, Starboard Engine, and House. You would be better off with two batteries on that House leg.

As long as you DO NOT select ALL, you can run the House down to nothing and still have both P and S engine batteries untouched.

If, for some reason, one of the engine batteries goes dead, just switch THAT ENGINE's switch to ALL and start it right up. There is a danger on some setups in changing switch positions involving the engines while they are running, so safest not to turn engine switches while they are running.

It is generally considered good to turn off all power when you leave the boat, but I keep my shorepower circuits on all the time and the other 12V legs on unless I'm leaving the boat for a long time.

Most of the time, you will arrive at the boat, turn "on" all three red switches, start the engines, have fun and reverse that process after returning to the dock in preparation to leave the boat.

If one leg is dead, you can briefly turn it's switch to "all" in order to get power from another 12V leg, start the engine, charge the battery a bit, turn the Switch back to 1 (on) jAFTER SHUTTING DOWN ENGINES and go on as usual.

It used to be that a boater would need to go thru all kinds of gymnastics on those switches to charge or protect a circuit, but now the charger and battery maintainer handle all that automatically.

You just turn them on to go and off to leave the boat and very rarely turn to ALL. For sure do not turn the HOUSE to ALL and run down the motor starting batteries watching TV!

John

thataway · Posted: Wed Jan 09, 2008 6:43 pm Post subject:

Sorry Charlie that you didn't understand my previous post. I thought it was clear--but have gone back and edited it, with spelling out Starboard and adding "Switch" where necessary.

The end result I believe is still clear--that is when you are at anchor, you run the boat on #2 position of the Port battery, assuming that your house battery is hooked up to this position. Boats may very, since the house banks seem to be added by dealers and not all boats are factory rigged.

When you leave the boat--all battery switches are "off". The battery chargers will still charge. I have an additional charger of 40 amps because the factory charger is not large enough to be effecient to charge the batteries from the generator in a reasonable length of time.

If you have a specific question I will be glad to answer it. The VSR is an important addition to these boats, and allows the batteries to remain isolated without fooling with the switches. As I noted, I have changed my boat and added more batteries, since for the type of cruising I do, the standard single group 27 battery is not sufficient for refigeration etc.

Bad Boy · Posted: Wed Jan 09, 2008 7:48 pm Post subject: Battery Switches

I have a 2008 Tomcat, Delivered on 8-31-07.

One switch should be Blue Seas dual battery switch that turns on power to both engines from their associated battery at the same time, Position 1-On. Starboard battery is connected to starboard engine at the same time that port battery is connected to port engine. They are separate circuits but the advantage of this switch is you use one lever to connect them. There is another position "Combine" which will combine the two engine batteries together in the event one is weak.

The other switch should be a switch strictly for your house battery in Position 1-On. When you switch it to Position 2-Combine, it provides the power to the switch above for your starting batteries.

If your starting batteries are both weak, turn their switch to "Combine" and the House Battery switch to "Combine" to help start your engines.

drjohn71a · Posted: Thu Jan 10, 2008 10:21 am Post subject:

Bad Boy, They must have changed the switch setup since my 2007 TomCat. It has separate engine switches.

Same basic plan, though. Off when not using the boat, On when using the boat and only Combine when one leg is dead. And leave the 110V panel "ON" so the shore charger will work. The bilge pumps are wired directly to the engine batteries so will work whether switch is on or off until battery goes dead.

John

Bad Boy · Posted: Thu Jan 10, 2008 2:46 pm Post subject:

If you have a separate switch per engine battery, what switch do you use for the house battery?

thataway · Posted: Thu Jan 10, 2008 7:27 pm Post subject:

Both of the switches are 1 2 off all. The dual battery switch sounds like a good idea for the starting battery. It seems as if you will still want a voltage sensitative relay so that the house battery(2) will be charged when the engine is running. It is still desirable to have a way to combine the house and engine start batteries, when the engine is not running.

The house battery is connected to the "2" position of my Port engine battery. To run the house batteries, this switch has to be in 2 or "all".

But, some boats are different; the factory wiring changes, plus dealers may rig boats differently. So there may be no one answer.

drjohn71a · Posted: Sat Jan 12, 2008 11:10 am Post subject:

My house batteries are on a separate switch labeled "House". both batteries are treated as just one battery, though, not as two separate batteries on the House circuit. that is generally no problem to me, but down the line I may have to separate and check each one, or just replace them both if one goes bad. I usually just put new batteries in at the three year point anyway.

John