How many Batteries ?

[phwrd]

I am a self proclaimed seaman apprentice, so please bear with my rookie questions.

Just bought a 19 ft. boat that has a two batteries and one battery switch.

Is it possible or practical to add two more batteries, using the same switch? Will one 140 hp motor charge 4 marine batteries at once ?

No trolling motor to drain the batteries but have am/fm, vhf, gauges, pumps, live wells, gps & lorance.

Or is there a better alternative ?

I am going to have to rewire the boat anyway, just a thought as i don't want to get caught out in the Gulf (or anywhere) with no power.

Thanks in advance for your advise.

Pat

 

[Nova II 260]

Re: How many Batteries ?

2 are plenty, carry a jump pack if your apprehensive about your batt power.
And they're always good for free beer at the ramps.

 

[dmcb]

Re: How many Batteries ?

I believe 2 are plenty for your use.
Your switch is for 2 banks of batteries.
A bank is a separate 1 or group of batteries tied together.
What you do is this.
Bank 1. Lets call this your starting battery.
The positive lead from one of your batteries goes to the #1 post of the switch.
Bank 2. Your house battery. The positive lead from the second battery goes to post 2.
Bank 1 is not used at anchor. You leave the switch on 2 for this. If 2 goes dead you sill have a full #1 to start.
You can put the switch on both when the engine is operating and both batteries will charge. Don't worry if one is low and the other is charged. No harm will come and the battery needing the charge will get it. You will not overcharge the charged battery. No chance.
If you know #1 is charged you can start your engine on #2 with no harm.
Just know #1 is always charged and standing by to start if #2 is dead.
That way there is no chance of all going dead.
If you go long periods with a heavy draw, make #2 a large deep cycle battery.
Doug

 

[SuperNova]

Re: How many Batteries ?

I agree, two batteries is plenty, and one switch is all you need. Understood and operated properly this system is more than adequate. Doug and Nova offer very good advice.
--
Stan

 

[Boatist]

Re: How many Batteries ?

I also agree 2 is enough. If the AM/FM is a 1000 watt peice destroyers then get the biggest deep cycle you can aford for Number 2. Goup 27 or 31.

In terms of getting back I would suggest a Kicker motor about 15 hp that can be started with a roap. I go 26 miles out in my 21 foot and many times alone with no buddy boat. I use to really worry that some day the motor would not start and the wind would take me where ever it wanted.

When I added my 15 hp kicker and a EZ steer I no longer have that worry. It is good piece of mind to know I can get back at 5 Miles per hour but be in control. Also use the motor when trolling for Salmon or when backing in to a beach. Always start both motors before heading out then shut down the kicker. VHF Radio is also good to let the Coast Guard know your comming in on a backup motor. They will set up a comm with your and check on your progress. Also a GPS of any size to aid in keeping track of you position should everything go wrong.

We used our kicker one time to head in do to an operator mistake (mine). We were come back form up the coast about 20 miles on a course about 5 miles off shore when we saw 5 Humpback Whales out about another 1/2 mile so we pulled in as close as we felt safe to take a bunch of pictures. I shut the engine down and we took lots of pictures. Very rare to see 5 together.

After the pictures got ready to go and the motor would not turn over. My Wife a seasoned ocean goer was near panic. She never likes whales real close. I Started the kicker and put her on the wheel and gave her a compass heading and she calmed down right away.

At that point I went back and opened the engine up checked for fumes ask the wife to turn key to on postion for the main motor then jumpered the starter solenoide pick terminal with a screw driver. The engine started in less than half of a turn. Decided not to do any more testing until we got in. So closed up the motor and shut down the kicker went on in to port. Of course when we got in it started every time like it always had before. Pased every test.

Normally when I shut down the motor at Sea I take it out of gear and disengage the shifter and adjust motor rpms to about 700 Rpms then turn off. This has been my habit for ever. I Do it because the motor will start instantly at that setting. So if your out in the fog and see another boat or ship headed right at you or a big breaking wave can get under way in 2 seconds.

The day with the whales I am sure I did not do that and left the motor in gear. Ofcourse the netural saftey switch prvented the motor from turning over. Did not think about it at the time.

Whole point is how it calm down the wife and saved the day.

 

[PondTunes]

Re: How many Batteries ?

The two battery setup is a good one.. you already have a primary and a backup if you really have long outings where you routinely drain battery #2 then you should consider changing it to a deep cycle marine battery as suggested. If you STILL need more you could always wire a second deep cycle in parallel with your #2 battery the two batteries would function like one big battery. I really don't see the need for two batteries on bank #1 as it is serving to just crank the engine.

 

[drewmitch44]

Re: How many Batteries ?

I saw a boat this past boating season with 22 bateries. The guy had a I/O set up but inside the doghouse he had 2 electric motors that i think were supposed to be for those hybrid cars. It was pretty neat and the boat would go on plane as i followed him he launched his boat right after mine and i waited in the channel to see what it would do. He was able to get it to about 30mph or so. I followed him and watched my gps speed in mph to detirmine the speed. I dont know the run-time that he had but the whole idea was pretty cool. He wasnt out verry long i dont think. He said he was testing out something cause the whole system was a project he was doing. I bet it was quiet though.

 

[drewmitch44]

Re: How many Batteries ?

Ohh i ment to put in there that it took a whyle for him to get on plane. It did do it though just didnt jump right up like my boat does. I have a 115 on a smaller sea-ray closed bow. Just thought id share about the electric boat.

 

[phwrd]

Re: How many Batteries ?

You folks are great !

Thanks for all of your advise, I will go with the 3 battery setup.
2 deep cycle on # 2. And will start looking for a "rope pull" kicker.

Again, i salute you and thank you for taking the time to help me with your answers.

Pat

 

[PhatboyC]

Re: How many Batteries ?

With the one protective switch and two battery setup, they said not to turn the switch from "1" to "both" when the engine is running. In case the switch doesn't do it's job and kills your alternator. It's also not good to start the boat on the switch set to "both". So how are we supposed to place the switch to "both" safely to charge both battery?

 

[SuperNova]

Re: How many Batteries ?

With the one protective switch and two battery setup, they said not to turn the switch from "1" to "both" when the engine is running. In case the switch doesn't do it's job and kills your alternator. It's also not good to start the boat on the switch set to "both". So how are we supposed to place the switch to "both" safely to charge both battery?

You need to make sure the switch is a "make before break" style switch. You can then switch it with the engine running with no trouble. I do it all the time and I have 2 batteries, 2 engines, 1 switch.
--
Stan

 

[PhatboyC]

Re: How many Batteries ?

Got it, thanks!