Dual Battery Setup and Battery Charging

frozenpod
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Re: Dual Battery Setup and Battery Charging

Post by frozenpod » Fri Feb 09, 2018 3:16 pm

Sinsemilla wrote:Not sure about tohatsu outboards but usually its just under 2k? Don't quote me though..
Typically the alternator will put out what it can at lower rpms but doesn't reach full current until around 1800rpm. At idle there is more than enough output current to put some charge into the battery if there is minimal load ie sounder radio and motor running.

smile0784
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Re: Dual Battery Setup and Battery Charging

Post by smile0784 » Fri Feb 09, 2018 4:15 pm

sturgeon wrote:
purple5ive wrote:
sturgeon wrote:
purple5ive wrote:if the price quoted is icluding the supply and fit of 2 marine batteries (make sure its the right size), the cabling and the switch, then just get them to do it.
No. Its the price for 1 battery and switch and cables. Not 2 batteries.
did they say what brand and size battery?
Marine century pro 680 I think.
680 it ok to run the electricals from to leave the main battery for starting the motor.

Hydroman
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Re: Dual Battery Setup and Battery Charging

Post by Hydroman » Fri Feb 09, 2018 4:45 pm

smile0784 wrote:
sturgeon wrote:
purple5ive wrote:
sturgeon wrote:
purple5ive wrote:if the price quoted is icluding the supply and fit of 2 marine batteries (make sure its the right size), the cabling and the switch, then just get them to do it.
No. Its the price for 1 battery and switch and cables. Not 2 batteries.
did they say what brand and size battery?
Marine century pro 680 I think.
680 it ok to run the electricals from to leave the main battery for starting the motor.
You need to match the same CCA as the battery currently installed. This is paramount is they are being charged in parallel which most likely they are. Etec's run a separate regulator for twin batteries so I "assume" you may get away with different CCA batteries with an Etec if using the 2nd charging point. If the dealer is offering a different CCA battery I would walk away. You will never get a full charge into the bigger battery if they are different sizes.

sturgeon
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Re: Dual Battery Setup and Battery Charging

Post by sturgeon » Fri Feb 09, 2018 4:55 pm

Mine is not ETEC. By the way, if I get a trolling motor or anchor winch in the future, would the 680 century pro be OK or do I need to have a dedicated deep cycle?

Hydroman
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Re: Dual Battery Setup and Battery Charging

Post by Hydroman » Fri Feb 09, 2018 5:05 pm

680 will be fine if you run everything off the house battery but for the engine start. as long as you have one good battery to start you are fine. I run a portable fridge off mine during summer and I just keep on eye on the battery volts. if they get down too low...i turn the fridge off. The only thing on the main battery is the engine which is a common setup.

But...please be mindful that you need to have the same CCA for the house battery as main battery. this is paramount.

What size battery do you have now?

With the anchor winch.....they pull a few amps so start the engine 1st. This is just good practice anyway as you are going to need the engine anyway. I do not have a winch but start the engine 1st as i do not like the idea of pulling anchor unless i know the engine will start. silly...maybe...but its a habit my father taught me 40 years ago and I wont change now!

smile0784
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Re: Dual Battery Setup and Battery Charging

Post by smile0784 » Fri Feb 09, 2018 6:13 pm

Hydroman wrote:
smile0784 wrote:
sturgeon wrote:
purple5ive wrote:
sturgeon wrote:
No. Its the price for 1 battery and switch and cables. Not 2 batteries.
did they say what brand and size battery?
Marine century pro 680 I think.
680 it ok to run the electricals from to leave the main battery for starting the motor.
You need to match the same CCA as the battery currently installed. This is paramount is they are being charged in parallel which most likely they are. Etec's run a separate regulator for twin batteries so I "assume" you may get away with different CCA batteries with an Etec if using the 2nd charging point. If the dealer is offering a different CCA battery I would walk away. You will never get a full charge into the bigger battery if they are different sizes.
Never heard of that but you're theory sounds solid

Hydroman
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Re: Dual Battery Setup and Battery Charging

Post by Hydroman » Fri Feb 09, 2018 6:40 pm

smile0784 wrote:
Hydroman wrote:
smile0784 wrote:
sturgeon wrote:
purple5ive wrote:
did they say what brand and size battery?
Marine century pro 680 I think.
680 it ok to run the electricals from to leave the main battery for starting the motor.
You need to match the same CCA as the battery currently installed. This is paramount is they are being charged in parallel which most likely they are. Etec's run a separate regulator for twin batteries so I "assume" you may get away with different CCA batteries with an Etec if using the 2nd charging point. If the dealer is offering a different CCA battery I would walk away. You will never get a full charge into the bigger battery if they are different sizes.
Never heard of that but you're theory sounds solid
thanks. I only ever post information that I am sure about. I just went to Dr.google to make sure I was on the money and was not incorrectly recalling something I was told a while back.

https://www.optimabatteries.com/en-us/e ... s-parallel

I actually thought the regulator cuts out at the lower battery. By this article the regulator halves the difference which makes more sense to me now i read it. Essentially you will overcharge one battery and undercharge the other.

PS....i am a real part time poster of this site but I like the way people are able to share views without any aggression. I really should become more active.

smile0784
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Re: Dual Battery Setup and Battery Charging

Post by smile0784 » Fri Feb 09, 2018 6:59 pm

In my old boat i use to run seperate 620 size battery deep cycle for motor and a got a 2nd battery from a 2nd hand parking machine battery to run the gps, sounder and live bait pump and never had any issues.

About 2 years later i decided to install a 3 way switch and joinded them partially together amd always run the switch of both with nil issues.

I set it up so could start the motor off the smaller second battery if needed but never needed.too.

sturgeon
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Re: Dual Battery Setup and Battery Charging

Post by sturgeon » Fri Feb 09, 2018 9:06 pm

Hydroman wrote:680 will be fine if you run everything off the house battery but for the engine start. as long as you have one good battery to start you are fine. I run a portable fridge off mine during summer and I just keep on eye on the battery volts. if they get down too low...i turn the fridge off. The only thing on the main battery is the engine which is a common setup.

But...please be mindful that you need to have the same CCA for the house battery as main battery. this is paramount.

What size battery do you have now?

With the anchor winch.....they pull a few amps so start the engine 1st. This is just good practice anyway as you are going to need the engine anyway. I do not have a winch but start the engine 1st as i do not like the idea of pulling anchor unless i know the engine will start. silly...maybe...but its a habit my father taught me 40 years ago and I wont change now!
Good point about starting the engine. True you should start engine before pulling anchor. :-)

sturgeon
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Re: Dual Battery Setup and Battery Charging

Post by sturgeon » Fri Feb 09, 2018 9:12 pm

Was just on the century pro website. https://www.centurybatteries.com.au/pro ... ualbattery
It says for dual battery system, they recommend that the second battery be deep cycle. If that is the case, it will not be possible for both batteries to be exactly the same. So which deep cycle can I use to pair with the 680?

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