Adding 2nd battery

[SweeperForce]

Hello,
I've seen boat having multi batteries with a swith to select one or the other and even an off switch. Do they make a kit to buy of is this a homemade job.
How hard are these to put in?
Thanks,
tom

 

[cedarjunki]

Re: Adding 2nd battery

have you tried using the search method? there are many discussions on it

 

[Bifflefan]

Re: Adding 2nd battery

Hello,
I've seen boat having multi batteries with a swith to select one or the other and even an off switch. Do they make a kit to buy of is this a homemade job.
How hard are these to put in?
Thanks,
tom

You need a Perko or simular switch and a batt isolater is a good idea too.
There is a wiring diagram with a good switch, and also with a good isolater. wire them as directed and have fun.
You can get these at you favorite boat supply.

if you have an OB you may only want charge one batt or at least one at a time. use one for starting only and the other for anything else. your OB may not charge 2 at a time.

 

[skargo]

Re: Adding 2nd battery

have you tried using the search method? there are many discussions on it

x2, it's a good habit to search first, then start a thread later if you don't find the answer to your question

 

[NYBo]

Re: Adding 2nd battery

You may be able to find one or two here.

 

[Silvertip]

Re: Adding 2nd battery

If you are not electrically savy then this job is best left to the professionals. If you understand basic electricity, know how to terminate wires and battery cables, then this is a relatively simple addition. But before you start, have you asked yourself "why" you want the switch and do you understand what the various settings accomplish for you and when you would select BAT 1, BAT 2, BOTH and OFF. It doesn't help you if you use the switch incorrectly.

 

[SweeperForce]

Re: Adding 2nd battery

I have been working with 12 volt for about 10 years now, so I do know my way around most cars. Now an OB is a different beast altogehter. But the laws of 12 volt still apply. I plan on using battery 1 for cranking. Battery 2 for trolling, radio, fish/depthfinder, and trim/tilt. While on the trailer turn it to Off. Under what condition would I need to select Both? Sorry for not seaching better of this topic.

Thanks,
Tom

 

[cedarjunki]

Re: Adding 2nd battery

I have been working with 12 volt for about 10 years now, so I do know my way around most cars. Now an OB is a different beast altogehter. But the laws of 12 volt still apply. I plan on using battery 1 for cranking. Battery 2 for trolling, radio, fish/depthfinder, and trim/tilt. While on the trailer turn it to Off. Under what condition would I need to select Both? Sorry for not seaching better of this topic.

Thanks,
Tom

im not too familiar with outboards but ive heard they may not put out enough to charge 2 batteries.....
the reason i use 2 and the switch is 1 for only start/running and 2 for all my other stuff. marine radio, tunes, lights, livewell, etc...
i usually switch to both when i cruise from spot to spot....but the reason you would need to select both is if something happened to cause battery 1 to discharge(charging system fails) and you left your radio on or lights or whatever draining battery 2. neither battery has enough juice to start the engine switch to both and then your combining the power of both and might get enough to start it instead of paddling

 

[Silvertip]

Re: Adding 2nd battery

12 volts in a car behaves exactly the same as it does in a boat so there is no difference in wiring. The charging system in a car works (for all practical purposes) the same as in a boat. Juice is consumed from the electrical system by whatever accessories you have. Juice is also fed to the batteries to charge them. Here is where the switch enters the picture. You have two batteries. Why you added the second one has many reasons, most of which boil down to "just in case my start battery dies". Well -- carry a jump start unit would be a simple and inexpensive fix for that. But - since the second battery is installed you now need a way to charge it do you not? So when adding the switch, all loads (meaning every accessory except for an automatic bilge pump) would be connected to the COM terminal on the switch. BAT 1 goes to BAT 1 and BAT 2 goes to BAT 2. So you can now start the engine on BAT 1, BAT 2 or BOTH settings. When set to BAT 1 everything runs off BAT 1 and BAT 1 gets charged. On BAT 2, everything runs off BAT 2 and only BAT 2 gets charged. On BOTH, both batteries power everything and BOTH batteries get charged. Trolling motors and high power stereos, anchor winches, etc would get wired directly to the house battery. Now then -- for general operation, set the switch to BOTH and go boating. There is absolutely no reason to change switch settings throughout the day UNLESS you beach the boat, listen to the killer stereo for several hours or otherwise consume gobs of power which would deplete BOTH batteries. If you WANT to switch to BAT 2 go ahead. That's what its for and you will shift the loads to BAT 2 thus saving BAT 1 for starting. When you are ready to go again, switch to BOTH or BAT 1. If the engine starts in BOTH both batteries will charge on the next leg of the trip. Or you can switch to BAT 2 to send the highest amount of current to BAT 2 which was the most discharged battery. Again, the engine doesn't care where the juice is going. YOU determine where you want it to go. BOTH is nothing more than a switch that connects both batteries in parallel so the two look like one giant battery to the charging system, Hope this helps you. Many folks see these systems and feel they need one but don't understand why and can't comprehend how it works.