Need with what Battery is needed

[cyclops222]

Post #20 is all I do with the 1986 30 hp motor. I just did a FULL 4 hour recharge at 10 amps 2 days ago. After 6 ? years of winter storages in upstate N Y. No trickle charge. Just read 12.5 volts on rested battery. It was at 12 .3 right out of winter storage. A careful 10 amp charge rate does wonders.
I have 3 boat speeds. OFF Trolling and WOT.

 

[dingbat]

Your situation is probably not typical as you have a lot of stuff running off your batteries.

Don't know about that…….stereos draw huge amounts of current.

Don't see any “fishing” boats with wake towers and high powered stereos..

May not be typical of a small boat owner, but boats on our waters typically run a full compliment of navigation equipment and accessories as I do.

Anyhow, the point I’m trying to make is that charging is a function of charging system output over time.

You can’t properly size batteries w/o without taking into account total demand and charging resources. Nothing kills batteries quicker than sitting around semi-discharged for any length of time. Starting batteries are the worst offenders.

 

[ESGWheel]

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.

As to your original question about CCAs for a 2-battery set up, it more proper to think in terms of Amp Hrs (Ah) vs Cold Cranking Amps (CCA). Ah is the amount of energy the battery will put out. So, if running a device that draws 10 Amps a 100 Ah battery would theoretically run it for 10 hrs (Hrs = Ah/Amp or 10hrs = 100Ahr/10Amp).

CCA is all about starting an engine in cold weather, hence the name. Is CCA related to Ah? Well, yes. In general, a higher CCA means higher Ah. Here is a link to understand the relationship between the two.

So back to your question: it really becomes one of why you are looking to do a 2-battery set up. Per posts 3 and 9, it seems you are looking to have a “house battery” that will be heavily loaded and desire 2 batteries to be confident you will be able to start after a long day of having fun.

Thus, the idea of using a “starting battery” for the engine and a “deep cycle battery” for the house loads is appropriate.

This can be accomplished a number of ways, including the aforenamed Blue Seas Add A Battey kit mentioned by Dingbat in post 11.

But there are considerations including the run time you spend vs. the having fun for the day.

So, as mentioned in post 22 by Dingbat, this is what it comes down to: figure out the house loads you plan on using (i.e. the total amps being pulled while your engine is shutdown) and for how long (this will give you Ah needed for the house battery) vs. the amount of time you will spend with the motor above idle, as in running out to your fun time spots (this will give you the approx. amount of Ah your alternator will put out using 60A x time). If unsure of the amp draw of a particular house item, look at the data plate or use the fuse size for it (i.e., if fuse if 5A assume it’s a full 5A draw, while it will not be, it’s a conservative value).

Post that that evaluation along with your backup data and folks will be able to guide you as to your best fit solution.

 

[cyclops222]

Basic GOOD logic to have the best chance of not being stranded.
But the BEST thing to do ? Is a BIG battery ON OFF switch setup.
Only the motor starter circuit on 1 battery.
ALL else is on the house battery.

Note about the A C R type of charger on the boat. MANY will automatically ONLY ....FIRST..... start continuously recharging the more run down house battery. All that time each start up of the ENGINE battery is getting more run down.
Solution ??? If you do not have 120 vac power to plug into each day. You have a lot of reading about each of the ON BOARD battery chargers. Ideally you would want them to give you a couple ..... PRIORITY ... choices. Namely Engine fully charged FIRST !!!!!! Then do the house battery.

 

[Erico624]

Thank you all for the Great information. Won't be running anything crazy at first just want the boat to start and the outboard hydraulic pump and engine bay blower to run. Other stuff like fridge and stove and sink will come later. Just want to be in water and see how it goes.

 

[ESGWheel]

Just want to be in water and see how it goes.

Sounds like you are still digesting and reflecting > that is good as there is lots to digest. Here is the best article I have read yet on ACRs: link. Also while you are contemplating which way to go, get one of those LiPo ‘start’ batteries, something like this: link. That way you have a piece of mind for about 100 bucks with your current single battery set up while you figure out what you are going to do. When you do get to your decision point, post it for feedback and shared learning.

 

[dingbat]

Note about the A C R type of charger on the boat. MANY will automatically ONLY ....FIRST..... start continuously recharging the more run down house battery.

Interesting…..those I’ve worked with only close (combine) the two batteries once the “primary” (start) battery is fully charged and the motor is producing excess current.

Closes:
13.6 V for 30 seconds
13.0 volts for 90 seconds

Opens:
12.35 V for 10 seconds
12.75 V for 30 seconds

 

[ESGWheel]

Note about the A C R type of charger on the boat. MANY will automatically ONLY ....FIRST..... start continuously recharging the more run down house battery.

Interesting…..those I’ve worked with only close (combine) the two batteries once the “primary” (start) battery is fully charged and the motor is producing excess current.

Gents, while others may have different set points, they do tie together the two sides: house and start or more specifically A to B from the relay’s perspective, which is well understood. The side (A or B) the alternator is connected to will be the first receive charging but, at least for the Blue Sea ACR, they do not monitor the Status Of Charge (SOC) of either battery. Instead, it senses the voltage being applied and if reaches a particular threshold as described above, the relay closes connecting the A and B, thus charging both. Said another way, even if A was the side with the Alt. connected to it and A battery as low as 50% SOC the ACR will, within a few, close connecting A & B charging both sides. This link provides this info as well as ‘why two thresholds’ and much more in detail. Highly recommend reading.

Which ACRs monitor SOC? I would like to investigate those along with the Blue Sea I am considering. Thanks!