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Starting or Deep Cycle Battery

twinrigskier

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Engine is a EFI (Autronic system). Boat has a small stereo and is set up with two batteries. Should one battery be a "Starting" battery and other be a "Deep Cycle" or what is your guys opinion? Whenever I run the boat I would have to run it on the Starting Battery and switch over to the Deep Cycle when listening to the Stereo? I wouldn't mind having 2 Starting Batteries as they have more juice and I could run them on all if needed. I didn't know if the Autronics EFI worked better with one or the other.
I appreciate your guys time.
 

02HoWaRd26

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I got a lesson from AJ @ Barrett a couple months ago that blew my mind. I went and bought a new “engine” battery, it’s a high cc cranking battery. The electronics in an efi system are a lot more dependent upon the cca than just the starter, come to find out.
 

twinrigskier

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I got a lesson from AJ @ Barrett a couple months ago that blew my mind. I went and bought a new “engine” battery, it’s a high cc cranking battery. The electronics in an efi system are a lot more dependent upon the cca than just the starter, come to find out.
So your thinking maybe run one of each then? Good marine cranking battery for the engine to run off of and a deep cycle for the rest? Was thinking about just going the interstate route.
 

02HoWaRd26

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So your thinking maybe run one of each then? Good marine cranking battery for the engine to run off of and a deep cycle for the rest? Was thinking about just going the interstate route.
I run two FullRiver’s for stereo and an Interstate agm starting for the engine. Way i understand it you’re better with two starting a than two deep cycle but best to rin one of each so they are doing what they are designed to do.
 

DarkHorseRacing

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Engine is a EFI (Autronic system). Boat has a small stereo and is set up with two batteries. Should one battery be a "Starting" battery and other be a "Deep Cycle" or what is your guys opinion? Whenever I run the boat I would have to run it on the Starting Battery and switch over to the Deep Cycle when listening to the Stereo? I wouldn't mind having 2 Starting Batteries as they have more juice and I could run them on all if needed. I didn't know if the Autronics EFI worked better with one or the other.
I appreciate your guys time.
So you have a couple alternatives if you are looking to have the best of both worlds.

1. Optima's Blue Top (Marine) is a deep cycle and starting battery combined.

2. Anything Odyssey Extreme. These batteries have the CCA for a starter and the A/Hr of a deep cycle.

Personally I run (2) PC-2150 Odyssey's, and you can start and run the engine on one, use the other for the stereo, then keep the battery switch to the "stereo" battery and start the engine and let the alternator charge it up on the way home.

Its very important that the batteries have good ground strapping to the engine, so they deliver all the juice anything wants.
 

port austin pirate

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run an optima agm starting battery on one side, and larger deepcycle agm battery on the other, heard some bad reports on optima, but mine is still strong after about 6 years, replaceing it just becuase of age this year cranks 525 efi very well, I usually start en run on one battery and then switch to the other about half the run time, only run on both if it has not been charged for awhile, then switch back to one after it starts, one more thing in my boat the deepcycle battery always has some drain ( power to bilge pump ect) when I store the boat even though I charge batterys it will draw down even when bat switch is off so I just disconnect positive cable, other bat will open hatch.
 

rivermobster

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So the alternator makes a decision about what to do, based on the voltage it sees.

It does Not see two separate batteries, unless it's an outboard, that was designed to charge two batteries independently.

Point being?

Let's say your starting battery is fully charged. Your stereo batteries are depleted.

The alternator makes a decision based on the highest voltage it sees.

Add to the fact different type batteries require different charging rates. (look on your battery charger in your garage...you'll see a different setting for deep cycle, AGM, etc...)

See where I'm going with this??

I would run matching batteries no matter what, on a single alternator/voltage regulator system.
 

twinrigskier

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Is it okay to switch the Perko switch over from 1 to 2 while the engine is running ?
 

rivermobster

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Is it okay to switch the Perko switch over from 1 to 2 while the engine is running ?
I sure wouldn't. Alternators don't like that sorta thing. Neither do any of the other electronics in a modern boat.
 

twinrigskier

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Awesome. Thank you guys for your input. I appreciate your guys time.
 

yankcan0

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I have used Diehard cranking batteries in my Spectra 24XS for years. I use the Perko switch for A or B or Both. I installed a battery isolator in the system to keep one from drawling the other down if it becomes weaker. I usually run it on both while under way then will switch to just one if over nighting or parked for extended periods. That way I always have one up to cranking the engine in the morning. This has worked for me since 1978. My current batteries are going on 9 years and still good.
 
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