Can I add a second battery to a SX230

[Agnusdei]

@Agnusdei, where are you located? Someone might be able to let you borrow the diagnostic tool.

Is that ok to add a second battery to my sx230 and how should I connect the second one to the primarily as far cabling? Thank you.

(Moved to a new thread by Bruce).

 

[txav8r]

@Agnusdtei , you want to maintain your 12 volts, so your connecting in parallel, not in series. That means your just adding more cells and more amps capacity to your existing 12 volt battery, not creating a 24 volt battery. he positive terminals are connected to each other and then negative terminals are connected to each other. The most efficient way to connect them is a positive terminal of one battery and the negative terminal of the other battery to the load, but it won't hurt to just connect to both batteries + to + and - to - and then the load to one battery.

 

[Bruce]

@Agnusdei, we need a dual batter writeup. I will work on that.

If your electronics are stock then you really do not need dual batteries. I have dual batteries but that is because I have a Refrigerator in my SX230.

I used a $31 Blue Sea 6007 Battery Switch

I mounted the batteries in battery boxes and used battery cables that I purchased at tractor supply to connect the positive terminals on the batteries to the switch. Then I connected the two engine and one house positive leads to the output of the switch. I used another tractor supply cable to connect the negative terminals on the two batteries. Finally I connected the two engine and one house negative leads to the batteries. I put the engine negatives one one battery and the house on the other. The negatives are tied together so it does not matter where you connect the cables. I connected them where they fit most easily.

I normally run on a single battery keeping the second in reserve. Using this method the second battery could be a smaller battery.

Many members install ACR (Automatic Charging Relays) to charge a starting battery before the house battery. We swim a lot when we are out so I do not expect the engines to recharge the batteries when we are under way. I added an on board charger and expect it to charge the batteries when I have shore power. So I do not have an ACR.

I do have a Blue Sea Systems 7635 Low-Voltage Disconnect


It is installed in the house circuit and cuts power if the voltage falls too low. Using it I know that the house circuit can not run the battery low enough to damage it or prevent starting.

 

[txav8r]

Just consider using"tinned" marine grade wiring and cable. Any marine environment is corrosive but boating in salt air and not having tinned wiring is going to set up corrosion faster. While it is more expensive, corrosion causes resistance and resistance is heat. I have numerous battery diagrams but rather than posting them indiscriminately, I would rather know what it is you have and want to do, and give you recommendations that suit your needs.

 

[Bruce]

Just consider using"tinned" marine grade wiring and cable. Any marine environment is corrosive but boating in salt air and not having tinned wiring is going to set up corrosion faster. While it is more expensive, corrosion causes resistance and resistance is heat. I have numerous battery diagrams but rather than posting them indiscriminately, I would rather know what it is you have and want to do, and give you recommendations that suit your needs.

Mel, I appreciate your marine grade battery cables. But if my $20 of tractor supply battery cables fail I will buy another set for $20 and spend 15 minutes swapping them They work just fine on my redneck boat!

 

[Island Jay]

Marine grade cables all the way. Murphy's law dictates they will not ( not if ) when you need it most. AKA a dead battery in the middle of no where surrounded by sharks.

But seriously yes non marine grade will work if it is the right gauge temporarily, but if you are near salt water I would give them 2 weeks, max.

FYI I sell boat battery chargers, not cables, so I am not trying to sell anyone any cables.

 

[ScarabMike]

Marine grade everything. Also, it all depends on what your trying to do with your system. I did a switched separate circuit for my boat because I like to go out in the ocean, and also because I like to play my radio that has 3 amps installed. So I wanted to isolate one battery, and be able to use another for back up. Kinda piece of mind. Or you can have one side a cranking battery, and the other side an AGM battery. You can switch to AGM for play time, and Cranking for the engine. AGM batteries are deep cycle, and have less CCA but will spread the charge out, and will also charge quickly. Cranking batteries will have a high initial spike to start the engines, but the charge will not last as long as a deep cycle.
http://www.boatingmag.com/how-to/how-to-install-marine-dual-battery-system

You can also connect them in parallel with no switch. This will spread the draw between both batteries, and it will give you a better CCA. But unless you have a high wattage alternator, charging times will be longer. Also, if you do this, you have to monitor your batteries condition often. Since there isnt a switch to separate the batteries in the circuit, if one battery is bad or will not hold a charge, it will affect your other battery. Then its a guessing game.

Only wire the batteries in series if you have a 24 volt system in your boat. You will fry almost everything if not a 24V system.

 

[Island Jay]

Marie grade everything. Also, it all depends on what your trying to do with your system. I did a switched separate circuit for my boat because I like to go out in the ocean, and also because I like to play my radio that has 3 amps installed. So I wanted to isolate one battery, and be able to use another for back up. Kinda piece of mind. Or you can have one side a cranking battery, and the other side an AGM battery. You can switch to AGM for play time, and Cranking for the engine. AGM batteries are deep cycle, and have less CCA but will spread the charge out, and will also charge quickly. Cranking batteries will have a high initial spike to start the engines, but the charge will not last as long as a deep cycle.
http://www.boatingmag.com/how-to/how-to-install-marine-dual-battery-system

You can also connect them in parallel with no switch. This will spread the draw between both batteries, and it will give you a better CCA. But unless you have a high wattage alternator, charging times will be longer. Also, if you do this, you have to monitor your batteries condition often. Since there isnt a switch to separate the batteries in the circuit, if one battery is bad or will not hold a charge, it will affect your other battery. Then its a guessing game.

Only wire the batteries in series if you have a 24 volt system in your boat. You will fry almost everything if not a 24V system.

I cannot tell you how many times I get calls from customers who connect a 36v system to a 12v charger, or any combination of things. They assume, don't ask, but, and it cost them more money in the long run.

Charger Guy PSA.... just because you are using a 12v battery does not mean you need a 12v charger. Got questions on this? Feel free to ask.

 

[Glassman]

I have dual batteries but that is because I have a Refrigerator in my SX230.

REALLY? Keep rubbin' it in Bruce, keep rubbin' it in...

 

[Jim Robeson]

Be careful @Glassman...he'll be "On You" before you can play a jazz flute!!

 

[Glassman]

Be careful @Glassman...he'll be "On You" before you can play a jazz flute!!

Oh I'll risk it

 

[ScarabMike]

I cannot tell you how many times I get calls from customers who connect a 36v system to a 12v charger, or any combination of things. They assume, don't ask, but, and it cost them more money in the long run.

Charger Guy PSA.... just because you are using a 12v battery does not mean you need a 12v charger. Got questions on this? Feel free to ask.

Ive seen it happen in my field generator locations a million times. They end up frying the control boards, and then the cell tower shuts down. Oooopps Dead Zone,lol!!