Installing Dedicated Starting Battery

[Ralph Masters]

I am almost completed with my electrical system upgrade and installation of a starting battery.  The only question I have is should the exhaust vent fan aft be rewired to come off the house system so as to prevent running the new start battery down while motoring??  Or is this a none issue and after I start the engine I can turn off the vent fan.  (This is all because we are looking at installing a refer unit to make the ice box a fridge)  Is the Sea Frost units worth the money??

Ralph
Ciao Bella
1987

[sailaway]

Ralph I own a 1986 we didn't have exhaust fans aft. So I would put it   on the house bank. I mounted a starting batt in the the port locker. I have my autopilot on the starting batt so I have to switch over to the house bank. I mounted a big red switch in the head so I can go house or starting batt.Charlie

[scotty]

Ralph,

Could you post a wiring diagram of your installation?  I'm going to do that job at some point and would like to see your system.  Two specific questions I have is how is the alternator wired up, and did you use an echo charger? (and why or why not)?

Thanks,

Scotty

[Stu Jackson]

1.  I am almost completed with my electrical system upgrade and installation of a starting battery.  

2.  The only question I have is should the exhaust vent fan aft be rewired to come off the house system so as to prevent running the new start battery down while motoring??  Or is this a none issue and after I start the engine I can turn off the vent fan.  

3.  (This is all because we are looking at installing a refer unit to make the ice box a fridge)  Is the Sea Frost units worth the money??

Ralph,

1.  Great idea.

2.  Usually the "blower" is energized from the switch on the cockpit panel, so it is energized from whatever battery bank is selected from the 1-2-B switch.  It is rarely wired directly to any individual battery bank.  "Running the new start bank down" simply does not happen.  For many years we have been making the point that starting an engine takes almost NOTHING out of the start battery. It's a high amperage draw for an incredibly short time.   We have also been suggesting that using the house battery for everything works just fine, and one uses the start battery as a reserve.  There are also many posts about wiring switches so that the reserve bank is used always to start the engine, based on how one wires the batteries.  You may have already poked around in the "Electrical 101" topic.

3.  You'll love the convenience of a fridge.  I suggest a Google search "sea frost, Maine Sail" - he's made some great contributions to boat fridge & electrical systems on other boating forums.  Good luck.


PS   I did a Google search, and came across this from our very own forum with a link to Main Sail's writeup:  http://c34.org/bbs/index.php/topic,7711.msg52990.html#msg52990

[Ralph Masters]

Scoty,
I'll get a wiring diagram posted.  I'm running a wire from the AO direct to the house bank and fusing it going to the battery terminal.  The start battery will have a wire from the charger directly to it.  I use the blue seas terminal block fuses because they are compact and fit well in the battery boxes.

Ralph

[Ken Juul]

I replaced my old Norcold with a Sea Frost, freezer box, not the plates.  Has really worked well this trip.  Thermostat is on about 1/4, freezes chicken or porkchops in about an hour.  I wrote post about it with more info.  Compared to the other units I saw at the boat show....yes it is worth the extra money.

[Ken Juul]

Personal preference, I use a Blue Sea ACR to charge my start battery, both through the charger and via the engine.  First unit I had failed a bit after a year old, replacement sent, no questions, send the old one back to get analyzed.

[Clay Greene]

If you are running the blower while the engine is operating, isn't your starting/reserve battery getting recharged by the alternator output? 

But I agree with the point that the blower is wired into the engine panel and there is no reason why you would wire it separately to any individual battery or bank of batteries.