Off Topic Wiring & Battery Questions

[sterlingz]

Hi all,

Hoping to get some advice on wiring, batteries, charging, etc.

I have a bare boat with tons of gear to wire up. Mildly confused but I think I have it figured out. Just want some confirmation and maybe clarity on some questions below.

Here's what I have:

• 2x downriggers
• Fish finder
• Ulterra (36v)
• 3x lithium batteries (100Ah each)
• Cranking battery

Plan so far:

• Lithium batteries in series to produce 36v.
• 8AWG with proper disconnects and 60-70A plug to Ulterra.
• Step down to 12v to power fish finder and downriggers OR power from cranking battery (undecided).
• Charge all batteries from outboard.

And now my questions:

• Boat is docked with no shore power. I take batteries home to charge, would you guys recommend a 36v charger (43.2v to be exact) or a 3-bank charger? I'd like to keep the batteries connected as a bundle so I'm leaning toward the 43.2v charger. Am I missing anything here?
• Is stepping down to 12v ok? I see conflicting information online, and my intuition is that stepping down to 12v from 36v is probably best. Others suggest powering all low draw equipment from the cranking battery.
• What's the best approach for distributing power from the alternator to the 36v bank?

I appreciate any input!

 

[Outdorman]

I always had a battery switch to make sure I could always use the trolling battery to back up the main battery for starting, not sure how you would do that with a 36v though.

you will probably be installing new toys down the road, so kinda like a house, do some pre-wiring for lights, speakers, power seats etc. Maybe even lay down a pulling cord, I'm thinking a bundle of wires in a loom/tray and have all cables together which is like my King Fisher.

sucks having to take 3 batteries in and out every time

 

[Wildfire]

I did everything you mentioned, but with SLA batteries which make it a whole heck of a lot easier. I don't think the solutions to do what you're asking are quite there yet with lithium. It's the charging from the outboard part that's difficult.

 

[G.Mech]

There's quite a lot to unpack here, but the biggest thing I see is that you do not want any of your electronics wired to your trolling motor batteries... The motor will almost certainly cause all kinds of interference. You may want to consider a house battery for your electronics, a cranking battery for your engine and whatever you need for your 36 volt trolling motor completely separate. The house and cranking batteries can be connected through a switch or automatic charging relay, but that system really needs to be separate from your trolling motor system.
This really won't lend itself to battery removal for charging so without shore power I'm not sure how practical this all is....

 

[FrankTheTank]

I always had a battery switch to make sure I could always use the trolling battery to back up the main battery for starting, not sure how you would do that with a 36v though.

you will probably be installing new toys down the road, so kinda like a house, do some pre-wiring for lights, speakers, power seats etc. Maybe even lay down a pulling cord, I'm thinking a bundle of wires in a loom/tray and have all cables together which is like my King Fisher.

sucks having to take 3 batteries in and out every time

imisscomunicatingif you run your wires thru a conuduite live a pvc pipe or add one for later down the road upgrades as long as you leave both ends visable you can either wire snake with the metal snake or a string in one end and a shop vac taped to the other you can eisly chase new wires back and forth after the remodle and for the cost of the pipe it would be worth it to do now. Im sure a year or 2 fishing on your boat and your goi g to want to change things up a little to suite your style better

 

[Black Baron]

I have a separate battery for the Riggers and electronics , 1 for Cranking , 1 for riggers and Electronics , and 3 for the Ulterra Quest..
I have 2 on board Chargers a 2 bank for the Cranking and Electronics Battery , and a 3 bank for the Bowmount. in your case I can see the hassle of not having shore power it sucks that you have to take the batteries home to charge .. However I have had the situation last year on 2 occasions where I drained my cranking battery by running my electronics from my cranking battery so I added a dedicated deep cycle just for the electronics.

 

[rockin-steelhead]

This is how I have my boat wired up

2x group 27 batteries for bow mount
1x battery that my kicker motor is connected to that runs all the toys..riggers..finders etc
1x cranking battery for the big motor

I also carry one of those battery booster packs with me for if ever I need it or someone else on the water needs a boost. Way easier to use that to boost they using booster cables etc.

 

[Windy Point]

I am in the process of doing/ installing....36v Terrova, Minn kota 4 bank 15 amp battery charger and wired it for shore power.

Personally I would have zero confidence your main motor has anywhere enough alternator to charge 4 batteries , unless you ran around the next day at wot, all day.

I went shore power hook up because I felt it was easier carrying a hundred foot extension cord than disconnecting four batteries, dragging them out from their hiding places and lugging them back and forth twice a day. To me that would get old Very fast. But the charger did cost me a few bucks.

 

[Windy Point]

Well your motor is not going to charge a 36v battery system, it is not designed for that. You will have to wire things so your motor charges your three batteries in parallel - 12v,12v,12v plus 12v for your cranking battery.

 

[rastam4n]

I have more concerns with your plan than I have time or effort to explain.
In all honesty. If you have to ask you should hire a professional.

You will likely save money.

 

[HTHM]

I have more concerns with your plan than I have time or effort to explain.
In all honesty. If you have to ask you should hire a professional.

You will likely save money.

If you go this route, I would strongly suggest Grimsby Tackle, he does extremely good work.

 

[Fshrmn4life]

Have you considered adding a Minn Kota
Alternator to the boat? If you added a house battery for all your electronics this would the house as well as your main were always charged. Only thing I am unsure of is if the Minn Kota Alternator is capable of charging Lithium batteries on the go, but maybe someone else with more knowledge of them can chime in on that.

 

[Bandwagon]

This is how I have my Ranger rigged.

3 X 12V 100AH lithium batteries for my 36V trolling motor.
1 x 12V size 31cranking AGM battery (4 graphs, power poles and pumps)
4 bank charger rated for both AGM and Lithium batteries.

I will be adding a exclusive battery for graphs in the coming weeks as I can not fish the day on that single AGM. I would exhaust every effort the find shore power.

 

[sterlingz]

This is how I have my Ranger rigged.

3 X 12V 100AH lithium batteries for my 36V trolling motor.
1 x 12V size 31cranking AGM battery (4 graphs, power poles and pumps)
4 bank charger rated for both AGM and Lithium batteries.

I will be adding a exclusive battery for graphs in the coming weeks as I can not fish the day on that single AGM. I would exhaust every effort the find shore power.

Yeah I'm thinking of just moving the boat to a different spot strictly for shore power.

sucks having to take 3 batteries in and out every time

Wouldn't be every time, probably every 3-4 outings, and I take nothing with me usually.

I did everything you mentioned, but with SLA batteries which make it a whole heck of a lot easier. I don't think the solutions to do what you're asking are quite there yet with lithium. It's the charging from the outboard part that's difficult.

Check this thing out, it's made specifically for this application: https://drewcraft.com/product/yandina-trollbridge-36-12-to-36-volt-battery-charger-combiner/

But unless you're using your main engine quite a bit, the extra recharge isn't really worth it, so I'm not going to bother.

There's quite a lot to unpack here, but the biggest thing I see is that you do not want any of your electronics wired to your trolling motor batteries... The motor will almost certainly cause all kinds of interference. You may want to consider a house battery for your electronics, a cranking battery for your engine and whatever you need for your 36 volt trolling motor completely separate. The house and cranking batteries can be connected through a switch or automatic charging relay, but that system really needs to be separate from your trolling motor system.
This really won't lend itself to battery removal for charging so without shore power I'm not sure how practical this all is....

It's practical if the cranking battery can stay charged (it should).

I have a separate battery for the Riggers and electronics , 1 for Cranking , 1 for riggers and Electronics , and 3 for the Ulterra Quest..
I have 2 on board Chargers a 2 bank for the Cranking and Electronics Battery , and a 3 bank for the Bowmount. in your case I can see the hassle of not having shore power it sucks that you have to take the batteries home to charge .. However I have had the situation last year on 2 occasions where I drained my cranking battery by running my electronics from my cranking battery so I added a dedicated deep cycle just for the electronics.

Have you noticed a difference in the Quest power consumption?

Have you considered adding a Minn Kota
Alternator to the boat? If you added a house battery for all your electronics this would the house as well as your main were always charged. Only thing I am unsure of is if the Minn Kota Alternator is capable of charging Lithium batteries on the go, but maybe someone else with more knowledge of them can chime in on that.

No it can't, you have to use the trollbridge for that. It supports balancing a house and cranking battery. But I may still use a Minnkota alternator and keep the trolling batteries separate.

 

[Black Baron]

I just got the quest 3 days ago so I have not had any time on the water yet, I am hoping that it is more efficient than the older brushed model

 

[Windy Point]

Was thinking last night, no shore power - install a four bank battery charger, wire for shore power, buy a Honda 2000 generator- power anywhere anytime.

 

[Wave Runner]

Have you considered adding a Minn Kota
Alternator to the boat? If you added a house battery for all your electronics this would the house as well as your main were always charged. Only thing I am unsure of is if the Minn Kota Alternator is capable of charging Lithium batteries on the go, but maybe someone else with more knowledge of them can chime in on that.

I have a Minn Kota alternator to help charge my trolling SLA batteries but it's not compatible with lithium LifePO4 batteries.

 

[Twister]

The Binnicale has great prices on Marine wire . You need to use Marine wire unless you want to redo it all every 5 to 7 years or you love that corroded green colour. I always run a separate wire for my fish finder and put a circuit breaker close to the batteries. I hook my depth finder to my start battery as they don't like dropping below 12volts and I draw my trolling battery below that. Id do what the manufacturer say about charging lithiums