Installing a second battery to help with big stereo...need help PLEASE

[vickerslane]

I have a 98 Sea Ray 180 and I am installing a new stereo system. I am going to be running a 2 channel amp for my tower speakers and a sub amp for my sub. I purchased a second battery to help out with the much larger power draw. I have never installed two batteries together so I wanted to make sure I could just hook up these two batterries together by simply hooking up the positive to the postive and the negative to the negative. I want to maintain 12 volts and not 24 volts. I saw some post saying I needed to install a battery switch but some didn't. I am wondering if hooking these up like this will charge both batteries....please help

 

[Splat]

Re: Installing a second battery to help with big stereo...need help PLEASE

Sounds like you'll he able to play music for everyone on the lake with the stereo your installing.....

What is the current battery powering on the boat you want to tie the new one off with? If its your starting battery I would isolate the 2 personally. I would wire the stereo to the current house battery, but move the start power to the auxiliary batt, then tie them together in parallel with a ACR. This will allow the stereo to run off the house battery while your stopped. When you start the engine the alternator will recharge the starting battery from the engine start, the acr will close then begin to charge both batteries in parallel.

You could use a switch but you would have to remember to flip it everytime you wanted to isolate, or combine the battery banks.

There's many other ways to do this, with many other configurations but this is the route I would choose.

Bill

Someone is gonna say it so I might as well. Sounds travels long distances over water. Many people don't want to hear your music. Please use it responsibly. Thanks

 

[Icyharp]

Re: Installing a second battery to help with big stereo...need help PLEASE

Well I have a switch in my boat as well but have 3 batteries. As you state you can run positive to positive and you will be fine. Anyone argues with that and have them open the hood of a diesel truck and see how the 2 batteries are routed, lol I have a Cummins and that is how they are done.

Reason I used 3 is because I have one for starting and since I have a cuddy we camp so I wanted 2 batteries to use for the lights and stereo and what not. I have 2 amps and 4 subs along with 4 other speakers to push when I am in the mood for some noise, so I added 2 on the other side of the switch.

Enjoy...!!!!!

 

[Silvertip]

Re: Installing a second battery to help with big stereo...need help PLEASE

Well I have a switch in my boat as well but have 3 batteries. As you state you can run positive to positive and you will be fine. Anyone argues with that and have them open the hood of a diesel truck and see how the 2 batteries are routed, lol I have a Cummins and that is how they are done.

Reason I used 3 is because I have one for starting and since I have a cuddy we camp so I wanted 2 batteries to use for the lights and stereo and what not. I have 2 amps and 4 subs along with 4 other speakers to push when I am in the mood for some noise, so I added 2 on the other side of the switch.

Enjoy...!!!!!

Certainly you can parallel the batteries. But unlike a diesel truck that can have six of them in parallel and whose only purpose is to power a a very big starter and a whole bunch of lights and relatively low power accessories, those batteries are also charged by a very big alternator, all of which you do not have. You only have TWO batteries and with a killer stereo, you need to protect the starting battery. You can't get out and walk if you are in the middle of the lake or 10 mles offshore. Battery switches and ACR's are designed for this purpose. If you are "switch challenged" then an ACR makes sense. If you understand the versatility and simplicity of the switch, then it will work. And contrary to popular belief, you don't need to be constantly fiddling with the switch. Set it on BOTH and go boating. If you beach for more than an hour or so, flip the switch to the house battery and know that the starting battery is protected.

 

[Icyharp]

Re: Installing a second battery to help with big stereo...need help PLEASE

I think I stated that I have a switch and was only replying to what he asked if "you could". As for the alternator, i am not even going to bother.........ugh. The question was asked, I answered, but you twisted my post around.

I think if you read my post correctly you will see that I stated that i was switched, so please read correctly before you jump down my throat and make assumptions.....thanks.

 

[vickerslane]

Re: Installing a second battery to help with big stereo...need help PLEASE

What is an ACR? How much are they and where do I buy one? Would an O'Reileys Auto Parts carry them?

Thanks for the advice everyone!

 

[ve3rpm]

Re: Installing a second battery to help with big stereo...need help PLEASE

The only way to run 2 batteries in parallel is if they are identical and bought at the same time. Very small differences because of age, use etc. will make for huge current transfers between the two batteries which is a really bad thing. There are battery isolators that you can buy, which is basically 2 diodes surrounded by a massive heat sink. One alternator in and 2 batteries out. The guys driving around your town with the pounders use these. Talk to a high end stereo installer and they can help out. Also, if your engine battery is down the switch will allow you to use the stereos battery to get you going.

 

[vickerslane]

Re: Installing a second battery to help with big stereo...need help PLEASE

What is the difference between these? Can I just get the ACR? http://bluesea.com/category/2

I am about to buy this and just hook it up to my two batteries. Will this be a good answer to my issue?
http://www.amazon.com/Blue-Sea-Automatic-Charging-Relay/dp/B000OTIPDQ/ref=pd_rhf_p_t_1

 

[Silvertip]

Re: Installing a second battery to help with big stereo...need help PLEASE

Certainly you can parallel the batteries. But unlike a diesel truck that can have six of them in parallel and whose only purpose is to power a a very big starter and a whole bunch of lights and relatively low power accessories, those batteries are also charged by a very big alternator, all of which you do not have. You only have TWO batteries and with a killer stereo, you need to protect the starting battery. You can't get out and walk if you are in the middle of the lake or 10 mles offshore. Battery switches and ACR's are designed for this purpose. If you are "switch challenged" then an ACR makes sense. If you understand the versatility and simplicity of the switch, then it will work. And contrary to popular belief, you don't need to be constantly fiddling with the switch. Set it on BOTH and go boating. If you beach for more than an hour or so, flip the switch to the house battery and know that the starting battery is protected.

So just how did I twist your comment around. My comment was about trying to compare the number of batteries being used and the actual difference between a truck and a boat. Running both batteries in parallel without a switch or ACR does absolutely nothing to protect the starting battery. If you care whether you run down the starting battery then connect them in parallel and go boating. Telling someone you can do something without telling why you shouldn't or what the ramifications are is a disservice. You don't need that protection with a truck since you are very unlikely to run down both batteries listening to the radio you do have. You also don't need a switch or ACR if you have an alternate means of charging the batteries. Once they are combined they are in parallel whether being charged or being discharged.

 

[Icyharp]

Re: Installing a second battery to help with big stereo...need help PLEASE

Silver, you quoted me in that first post and from the looks of it you are directing your statements as, "switch challenged" telling me what I have for an alternator etc...if you are directing your post to vickers then make it be known, but from me reading it with a quote from me it looks as if you are directing this issue towards me. Remember first I said I had a switch, then said I have 3 batteries, and 2 are hooked up the way he wants to do. Only stating that it can be done.
One other thing to remember how many boaters you see on the water with their radios on while swiming etc..with only one battery on board for long periods of time? I see plenty and do not run up to them and tell them they are fools for it. Reason I don't is cause I am on fresh water with lots of other boats in the area.....plenty of people that willing to help out, good grief even I have pulled one of my batteries to help a boater out cause his kid flipped the depth finder bow lights and radio but with no volume on and the boat was anchored for 10+ hours and his weak battery only fired the outboard once then it died, then click...lol. I let him use my battery all weekend as I ran around with his to charge it, then switched back.

Just thinking that when you see a quoted segment in a post most people see it as you are directing your post at them.

So ya I am taking it as you are telling me what to do,