Want to add battery specifically for automatic bilge pump

[Trips]

Hi all, I have a 1988 Sea Ray Seville with the 4.3L engine. The engine itself has an alternator to charge the battery. Next season I am going to slip the boat on the river and would like to have a dedicated battery to run the auto bilge pump at all times. If I buy a battery switch that allows me to choose either battery one, two or both, will the alternator on the engine be enough to charge both batteries? Mainly, I want to be able to shut down the main battery when I'm not using the boat, but still have one battery going to power the bilge. Ideally, the bilge-dedicated battery will charge when I am operating the boat with the battery switch in one&two position so I don't need to separately charge it.

 

[Silvertip]

Re: Want to add battery specifically for automatic bilge pump

Yes -- that will work. Using the Bat 1 & Bat 2 (BOTH) setting will charge both batteries. But again -- doing what you intend to do limits the versatility of the switch. If you are fully convinced this is what you want to do I won't discourage you but you are leaving "capability" on the table.

 

[nikon]

Re: Want to add battery specifically for automatic bilge pump

If running your bilge pump will be it's sole purpose you have no need for a switch. Just add one of these
http://www.iboats.com/Blue-Sea-Syst...6493212--session_id.690546171--view_id.729809
it will charge when the boat is running and auto disconnect when you shut the engine down. If your adding another battery you might as well wire it so you can use it to start the boat too though.

 

[Trips]

Re: Want to add battery specifically for automatic bilge pump

Yes -- that will work. Using the Bat 1 & Bat 2 (BOTH) setting will charge both batteries. But again -- doing what you intend to do limits the versatility of the switch. If you are fully convinced this is what you want to do I won't discourage you but you are leaving "capability" on the table.

Please, discourage away! What would be te best set up, in your opinion?

 

[NYBo]

Re: Want to add battery specifically for automatic bilge pump

Welcome to iboats!

The standard practice is to hook the bilge pump directly to one of the batteries, not to the battery switch, and just hook up the battery switch as per the instructions that came with it.

 

[Jlawsen]

Re: Want to add battery specifically for automatic bilge pump

Welcome to iboats!

The standard practice is to hook the bilge pump directly to one of the batteries, not to the battery switch, and just hook up the battery switch as per the instructions that came with it.

This is absolutely correct as it eliminates the human error factor.

I believe your best solution is the Automatic Charging Relay (ACR) but I recommend you get the full kit which is advertised as their Add-A-Battery system. This does give you a switch that will allow you to shut all your house systems completely off. You then wire the automatic bilge pump relay directly to a constant unswitched voltage source (second battery).

In this scenario the only draw on the battery would be the bilge pump when the boat is not in operation and the switch is off. When the switch is on but the ignition is off, the house equipment (stereo, radio, fish finder, etc.) run off the second battery. When the key is switched to on the ACR switches to Battery 1 and you have a fresh battery to start the engine with. When the engine is running the ACR senses the voltage in the two batteries and first brings the starting battery to full then switches to the second battery and charges it. If at any time while running, it senses a voltage drop at the starting battery it will return to charging it. This cycle may repeat several times.

The one thing to watch out for is if you use the second battery as a house battery and discharge it to say 40%, it would take about 8 hours of the engine running to bring it back to full. What I'm saying is don't go out then put the boat away thinking you have a fully charged battery protecting your boat if you decide to run your house equipment on the second battery.

If you don't run anything but the Bilge Pump off the second battery then no sweat.

 

[Silvertip]

Re: Want to add battery specifically for automatic bilge pump

The only capability missing from an ACR is the ability to start the engine from the house battery should the starting battery take a dump. With a dual battery switch you don't even need an ACR but that's a personal choice and is probably a better one if you happen to be "switch challenged". Just use the SEARCH feature to see how a dual battery switch can work for you. It's been discussed a gazillion times and most of the posts include diagrams.

 

[Howard Sterndrive]

Re: Want to add battery specifically for automatic bilge pump

My remote control battery disconnect has a dedicated "bilge pump" terminal. It is live even when the battery is off.
Keeps it neat as everything is right in the battery box.

also kind of cool to hit the remote from 100' away and hear the blower come on (I leave the blower switch on). By the time I reach the boat the blower has ventilated the engine bay nicely.

 

[Jlawsen]

Re: Want to add battery specifically for automatic bilge pump

The only capability missing from an ACR is the ability to start the engine from the house battery should the starting battery take a dump. With a dual battery switch you don't even need an ACR but that's a personal choice and is probably a better one if you happen to be "switch challenged". Just use the SEARCH feature to see how a dual battery switch can work for you. It's been discussed a gazillion times and most of the posts include diagrams.

Silvertip, the Blue Sea Add A Battery switch can go to both. Normal is 1 but there is a second BOTH Position they just don't have a 2 position because it's not necessary.

 

[Silvertip]

Re: Want to add battery specifically for automatic bilge pump

Silvertip, the Blue Sea Add A Battery switch can go to both. Normal is 1 but there is a second BOTH Position they just don't have a 2 position because it's not necessary.

BOTH (or the COMBINE) feature is fine if all that's wrong with start battery is that it is deeply discharged. Ever tried to jump a "dead" battery (dead being one or more dead -- as in non-functional cells)?? In that case BOTH/COMBINE does you no good. A switch allows the engine to start on BAT 2 only so the inability to jump a dead battery is eliminated. I'm not disputing the value of the ACR but rather pointing out the limitations since everyone seems so worried about a dead starting battery. Besides, the switch is cheaper, more versatile, and is a simpler installation.

 

[nikon]

Re: Want to add battery specifically for automatic bilge pump

How about you get the ACR and switch (off-1-both-2 switch). Leave everything else alone, as in your still only starting and using (draining) battery #1. Always keep the switch on #1 and wire the bilge directly to battery #2. If by chance you kill battery #1 you can switch it over to #2 and get home. In normal operation your never running down #2 so you'll always have your fully charged bilge battery. Seems like the most logical way to do it IMO.

 

[glenn property of pam]

Re: Want to add battery specifically for automatic bilge pump

if the boat is slipped with a cover then any battery set up already discust is fine. if the boat is open to rain water which goes to the biege and you have no power at the slip then i would install a second bilge pump wired to a cig lighter socket slightly lower than the original or higher then swap the wires over from the original then you can bring a charged battery and just plug it in. its amazing how much rain water can fall over the period of a week in florida no idea what your weather is like. so i like a back up plan thats simple to use. if you have power at the slip then just buy a battery charger and leave that on.