Dual Battery

I'm planning on reinstalling both batteries like I had last year. The way I did it last year was the "house" battery was only connected to the stereo and amp and it wasn't connected to the engine. I threw it on the battery charger at home. This year I'd like them both to be able to be charged by the engine. Here's my set up:

Starter Battery:

Marine Starting (24 Series)
625 CA
500 CCA

"House" Battery":

Dual Purpose (Starting / Deep Cycle)
875 CA
205 Reserve Capacity

**Goal**

Engine always charges batteries individually when the engine is running with priority to the starting battery. When engine is off the drain is always on the "house" battery, or never drains the starting battery below a certain level.

I've started reading about battery switches, relays, voltage sensing switches and voltage sensing relays. It kind of sounds like I should use a switch and VSR, but I'm not sure.

Can anyone provide some feedback or share your setup?

Randy...the link didn't work for me.

Not sure why the link isn't working I don't have time to look at it now..

try doing a search for hellroring on this site....

skicat2001 wrote: Thats a great question, and I have one as well too. I notice when I turn the boat off say for an hr or two, when I recranck the boat, I am down under 12 volts and then she powers back up to normal. For mine 13 volts is where mine normally rides, so if in a hr or 2, you lose volt amps, why does the boat suck that much apm, I dont use any radios to it.. Dont make since.. Is two batteries better to operate off of?

I'm not to sure what you're trying to say! When cranking the volts drop below 12? Then they go up past 13 but after running the engine for awhile it drops back to 12? If so, that would be normal. During cranking the load of the starter will produce a voltage drop. After starting the alternator kicks up to full to replace the power from the battery from starting. Then, the battery becomes fully charged and the alternator takes a rest! Volts go down.

Randy here you go

Hellroaring Battery Isolator

Thanks guys. I'm also looking at the Blue Sea solution. Basically it looks like it just adds a switch to the Hellroaring set up. Either one seems to only charge the battery that needs charging and keep them isolated, it seems to me. Does that seem right to you all?

Andy: Im going to use a Perko switch. They are about 20.00 bucks and you can get them at about any mairne store in Tulsa. You will need the two channle "A/B" switch. Basically you can run your stereo on battery A, When the battery goes dead you can switch to battery B and start your boat. Then place the switch on A&B to charge battery A. It is really simple. This is what my God father runs in both his boats. I don't think he has had a problem out of it yet.

I Sell around 5 a week of the Blue Seas system you have talked about it is one of the better systems on the market, have never had any problems with Corrosion as they are a fully sealed unit and have never had one weld together, as the current is so low (its only the charge current going through the VSR)

we use this system on anything from small boats like ours to 50-60 footers.

the real advantage is that battery switch also it keeps the 2 banks separate then if you ever run your start battery flat cranking you can combine the 2 banks to get the engine started straight away (just like jump starting)

i have not seen very many of the Hellroaring set up's around, seams a lot of people on here use them and are happy with them. the one thing i do not get about the way people seam to set up the Hellroaring system is they do not allow the batteries to be Connected in case of emergency to start the engine, this it one of the main reason i would have a second battery on board.

Randy_in_Ohio wrote: This setup will isolate the Aux. battery from the starting battery when the engine is off and, once the engine is running , will charge the starting battery first and then switch on at 13.4V and combine the batteries so that both are connected to the alternator.

This is from the other thread Randy had going regarding the Helroaring unit.

Here's a couple questions that came to mind when reading through the thread and especially this quote...

1. Combining the batteries sounds like a problem. Doesn't that put twice the load on the alternator?
2. Does the Blue Sea combine batteries or charge them seprately based n which one needs it?
3. With the toggle switch and LED's how are the batteries combined for starting?
4. On the Blue Sea, when the switch is set to combined how are the batteries combined for starting?

Good continued info Randy, thanks. I'll be sure to contact Mike to discuss further.

I like the fact you're still running on the original alternator and haven't killed it.

Okie Boarder wrote: Here's a couple questions that came to mind when reading through the thread and especially this quote... 1. Combining the batteries sounds like a problem. Doesn't that put twice the load on the alternator? 2. Does the Blue Sea combine batteries or charge them seprately based n which one needs it? 3. With the toggle switch and LED's how are the batteries combined for starting? 4. On the Blue Sea, when the switch is set to combined how are the batteries combined for starting?

AS said someone else has said it will bring your 1st battery up to around 80% charge (norm 13.7v) then it will combine them and allow the 2nd one to charge,

2nd, it will combine them (this is no problem at all every boat over 7m will do this)

4th, the batteries are combined in parallel (i hope i have this the correct way around but it still leaves it at 12v the other way would make it 24v)