Dual batteries

[laurido1992]

I'm debating whether to install a second battery. I don't have that many electronic devices. All I have is a radio and 4 speakers. I'm thinking of addind an amplifier. Other than the radio all I have is the normal stuff that comes with the boat (depth sounder, nav/ anchor lights, etc) What do you guys recommend???
Thanks for the input.

 

[bruceb58]

Re: Dual batteries

I would absolutely do it no matter how much electronics you have.

You will be buying a battery switch and some more cables. One more thing I would get is a battery combiner. This allows both batteries to be charged even though the battery switch is pointed to just one of the batteries. I would not use an isolater.

 

[studlymandingo]

Re: Dual batteries

Always nice to know you have another battery if you run one too low.

 

[jtexas]

Re: Dual batteries

only reason not to would be if you couldn't carry the extra weight...doesn't seem to be a factor in your case...depending of course on "cargo"...

8)

 

[laurido1992]

Re: Dual batteries

Thanks for the input. I guess I should get the same battery as the one that came with the boat, right?? I'm going to West Marine to check out the battery switch and the combiner and see how much cable I need.
Again, thanks for all the input. This is why I like this forum so much. You always have people willing to help and advice.

 

[Fishstick1962]

Re: Dual batteries

Yes! Add the battery and a battery select switch. I have a 2004 VIP 185 Vegas, and I carry 3 batteries.
I'm not gonna be dead in the water because of a lack of battery power.

 

[laurido1992]

Re: Dual batteries

I went to West Marine and talked to a guy and he said that probably the best thing I can do is add a deep cycle battery and have ALL electronics to the deep cycle and have the other exclusively for cranking only. Does this sound right?? He also said that if I do it this way, I wouldn' t need the battery switch. Thanks for the input.

 

[jtexas]

Re: Dual batteries

Yes, a deepcycle battery will power all your toys pretty much all day with power to spare; the switch isn't a necessity, you can add it later if you decide to.

Also its okay to leave some accessories on the cranking batt - bilge pump, sonar, nav lights, horn - the "essential" stuff. Alternator keeps it charged.

You could probably get by without another battery but you've got space, why take a chance. Anchoring in party cove with the tunes blasting is where you risk running out of cranking power. That's what I think anyway. If you're always on the move, you won't really drain the battery anyway.

Be sure to charge your new battery right after you get off the water - letting it set around in a discharged state will shorten its life.

 

[whiteman]

Re: Dual batteries

Wouldn't you be better to have both batteries available for cranking? I (manually) switch between my batteries from one trip to the next and trickle charge them if I'm not getting out regularly.

 

[pete963]

Re: Dual batteries

i would prefer to have a switch due to the fact that if one battery is going bad it will draw that much more off the good battery and you were that new battery down real fast...........so for the extra couple of dollars i would keep them seperate

 

[laurido1992]

Re: Dual batteries

I think I'm going to do the deep cycle batt with no switch for now. Maybe later I'll add the switch, although I really don't see the advantage of having it.

 

[jtexas]

Re: Dual batteries

just for clarification...adding a deepcycle without a switch means it will be a completely separate circuit from the cranking battery.


[note to whiteman: just my opinion...having both batts available for cranking isn't a bad idea, just a convenience that you will seldom if ever need. Worst case, you'll have to move batteries around - I carry jumper cables to cover that eventuality]

 

[whiteman]

Re: Dual batteries

jyexas
I carry kids on board and where I live there isn't a lot of traffic so I need to be prepared and having 2 batteries wired in gives me a safety margin. I have yet to need the 2nd battery but when I do, I really will need it!

My boat has 2 batteries with a switch for Off, A, A+B,B. I guess the downside is that I'm either drawing all power from either A or B, or with the switch at A+B, I risk a low battery drawing from a high battery. On the other hand this works really well in practice for my setup as I trickle charge the batteries at home and I feel safe that I'll have power unless both batteries pack it in at the same time.

 

[dingbat]

Re: Dual batteries

I really don't see the logic behind going as far as installing a second battery and then not complete the job with a battery selector switch. How are you going to charge them with only 1 output? How are you going to swap batteries should one fail?

I have 2- 27 series dual propose batteries on a switch and have plenty of power to run a full complement of electronics as well as a 4kW radar unit off of just one. I alternate both as primary supplies to keep them charged but the second is always used exclusively as a back up.

 

[jtexas]

Re: Dual batteries

I really don't see the logic behind going as far as installing a second battery and then not complete the job with a battery selector switch. How are you going to charge them with only 1 output? How are you going to swap batteries should one fail?

The logic is really not that complicated.
Problem: need a deepcycle battery for accessories.
Solution: add a deepcycle battery for accessories.

That completes the job.

To answer your specific questions:
Q. "How are you going to charge them with only 1 output?"
A. With a device called a "battery charger", which plugs into any ordinary household electrical outlet.

Q. "How are you going to swap batteries should one fail?"
A. Step 1: disconnect the failed battery.
Step 2: connect the other battery.
Alternative process:
Step 1: connect jumper cables to failed battery
Step 2: connect other end of jumper cables to good battery.
Step 3: start engine
Step 4: remove jumper cables from both batteries.

You have an excellent solution that works well for you. The one I described works for thousands upon thousands of boaters.

 

[vipzach]

Re: Dual batteries

Worst case, you'll have to move batteries around - I carry jumper cables to cover that eventuality]

This is exactly what I do, just like jtexas said. I two batteries and a set of jumper cables. I have never needed my cables to start my own boat, but I have helped several people get theirs started with them.

I like having two batteries on board, but don't want to bother with a switch. If you charge and maintain your batteries, you will probably never need the second one to get you going.

 

[dingbat]

Re: Dual batteries

I guess different strokes for different folks. Just not into battery chargers and extention cords I guess. d

Be very careful with those jumper cables. We had a guy at our marina blow himself and his boat to pieces while using jumper cables to start his boat. No power equaled no blower….well you get the picture.

 

[klicknative]

Re: Dual batteries

Why not just use an isolator so the accessery battery is being charged when the engine is running? I know running an isolator without a master switch takes away the option of cranking with the second battery but it's there to avoid discharging the main battery.

 

[ricksrster]

Re: Dual batteries

 

[bruceb58]

Re: Dual batteries

Very good point!

Be very careful with those jumper cables. We had a guy at our marina blow himself and his boat to pieces while using jumper cables to start his boat. No power equaled no blower….well you get the picture.