Need with what Battery is needed

[Erico624]

Hello, i have a 1985 Wellcraft 248 sportsman. Has a GM 5.7 350 motor in it. Want to run 2 Battery but not sure on CCA for 2 battery's. I have a 800CCA for starting atm.

 

[dingbat]

Hello, i have a 1985 Wellcraft 248 sportsman. Has a GM 5.7 350 motor in it. Want to run 2 Battery but not sure on CCA for 2 battery's. I have a 800CCA for starting atm.

For redundancy, you want both batteries to be able to start the boat on their own.

Beyond that, battery type and size would be dependent on how you want to use the two batteries

 

[Erico624]

For redundancy, you want both batteries to be able to start the boat on their own.

Beyond that, battery type and size would be dependent on how you want to use the two batteries

would like to use 1 for engine and 1 for accessories.

 

[dingbat]

would like to use 1 for engine and 1 for accessories.

Then run one starting battery and one deep cycle battery.

Bear in mind that you still need to charge them on a regular basis. Most don’t put enough run time on a boat to fully charge them after use.

 

[Erico624]

Then run one starting battery and one deep cycle battery.

Bear in mind that you still need to charge them on a regular basis. Most don’t put enough run time on a boat to fully charge them after use.

Ah ok i will look into a charger for the battery.

 

[dingbat]

Ah ok i will look into a charger for the battery.

You can install an ACR that will charge both batteries from your motor while running.

Add-A-Battery Kit - 120A - Blue Sea Systems

Simplifies switching and automates charging for a complete two battery bank solution.

www.bluesea.com

Problem being, most don’t run the motor long enough to fully recharge the primary battery, let alone the house battery.

 

[Erico624]

Ah ok i will look into a charger for the battery.

with 2 batteries should i look into a ACR system?

 

[Chris1956]

A V8 should easily keep both batteries charged. They have a minimum of 40A alternators. Some marine ones are 60A. What kind of accessories are you planning to run? GPS, LEDs and radios take minimum power these days.

I suppose if you ran a 24V trolling motor most of the day and just ran the main engine a short time you might need a charger.

You will want a battery switch.

 

[Erico624]

A V8 should easily keep both batteries charged. They have a minimum of 40A alternators. Some marine ones are 60A. What kind of accessories are you planning to run? GPS, LEDs and radios take minimum power these days.

I suppose if you ran a 24V trolling motor most of the day and just ran the main engine a short time you might need a charger.

You will want a battery switch.

You pretty much summed it up lol. You are the best!!

 

[dingbat]

A V8 should easily keep both batteries charged. They have a minimum of 40A alternators.

That is 40 amps per hour of run time.

Running 15 minutes out to the sand bar, burn up 80 amps of power, then running 10 minutes back to the marina isn’t going to cut it

 

[Chris1956]

What are you going to run that burns 80A?

Gee, switch the battery switch to one battery when you park. Run all your stuff, and then switchover to the fresh battery to start the motor. Switch to both with the engine running and drive home. If you want to be a big wheel, use battery 1 on odd days and battery 2 on even days. That is the way the sailors do it, and they have much less battery power.

 

[Erico624]

What are you going to run that burns 80A?

Gee, switch the battery switch to one battery when you park. Run all your stuff, and then switchover to the fresh battery to start the motor. Switch to both with the engine running and drive home. If you want to be a big wheel, use battery 1 on odd days and battery 2 on even days. That is the way the sailors do it, and they have much less battery power.

Interesting.

 

[dingbat]

What are you going to run that burns 80A?

I use close to that in an hour between fish finder, (20W) chart recorder (20W), 100W RMS stereo (480W), VHF (24W) and radar (80W)

624W/12V = 52 amp per hour just in electronics.

Does not included auto-pilot, phone chargers, lighting, bilge pumps, wash down pump or winch

How many amps do you burn starting the motor?

 

[Erico624]

I use close to that in an hour between fish finder, (20W) chart recorder (20W), 100W RMS stereo (480W), VHF (24W) and radar (80W)

624W/12V = 52 amp per hour just in electronics.

Does not included auto-pilot, phone chargers, lighting, bilge pumps, wash down pump or winch

How many amps do you burn starting the motor?

All those will be on a separate battery no?

 

[Chris1956]

So you run your radar, FF and chartplotter while at the sandbar? Seems unnecessary. Your stereo runs a 40amp fuse? That would require 8ga wire, I would think. Seems like overkill.

 

[dingbat]

So you run your radar, FF and chartplotter while at the sandbar?

I boat to fish…. have absolutely no interest in any “sand bars” except the ones they call the OBX. Those I fish from a beach buggy…lol

Inshore/ Offshore. 12 hour days offshore, 6-8 hour days inshore. Most days are 100% run time. Even then, I typical run a deficit at the end of the day.

All those will be on a separate battery no?

No starting battery. Running two (2) grp. 27 (120Ah ea.) deep cycle batteries with On-Off-Combine battery switch with an ACR managing charge functions.

Rewired the boat to add two (2) 100A fuse blocks (one per battery) at the helm for distribution.

Put essential navigation and communications on one battery. Back up navigation and stereo on the other. House loads are connected to accessory power terminal on battery switch.

Can be feed “house” loads with either battery (remove battery cable from “start” battery and flip switch to combine) should the need arise.

 

[Chris1956]

Gee Dingbat, in post 10 you said you ran out to the sandbar and used 80amps/hour. That was the source of my observations.

Now you say you never go to the sandbar and only fish with the engine running but use so many amps that a marine alternator cannot keep up. That is unusual.

 

[dingbat]

Gee Dingbat, in post 10 you said you ran out to the sandbar and used 80amps/hour.

Either you have taken things out of context to prove self right or you have a reading comprehension problem.

The post below was to advise the OP that rated output of the charging system is per hour of run time.

Where exactly does it say anything about me going to sand bars?

That is 40 amps per hour of run time.

Running 15 minutes out to the sand bar, burn up 80 amps of power, then running 10 minutes back to the marina isn’t going to cut it

 

[Chris1956]

Must be a reading comprehension issue.

That is 40 amps per hour of run time.

Running 15 minutes out to the sand bar, burn up 80 amps of power, then running 10 minutes back to the marina isn’t going to cut it

So you meant other people running out to the sand bar, but not you. It is clear to me now...

 

[KJM]

For redundancy, you want both batteries to be able to start the boat on their own.

Beyond that, battery type and size would be dependent on how you want to use the two batteries

Your situation is probably not typical as you have a lot of stuff running off your batteries. My f90 outboard keeps my one deep cycle battery charged up all season with no need to top up the charge. I seldom need to go more then a half hour from shore and once there, there is a lot of stops and starts to move around as the boat drifts off the fishing spots. That said my only other drain on the battery is a fish finder!