Batteries

[Shackleton]

I have decided to replace the two batteries that came with my used 2008 Searanger HT that I bought last fall so that I can start out with confidence in my new batteries.  What I pulled out of the boat was an Autocraft M24-1 Starting Marine with a CCA rating of 500 and an MCA rating of 625as well as a Kirkland Signature Deep Cycle Marine battery with a rating of 700 MCA and85 Amp hours with a group 24 DC label. My boat has the battery switch that can toggle between battery 1, 2 and "both".  What I have been reading online is that I maybe should buy 2 identical starting/deep cycle batteries to replace the set up that I pulled out?  I don't know anything about wiring and for this season plan to have simple electronics with GPS chart-plotter, depth-sounder, VHF, running lights, music radio.  The boat foes not have a kicker and I would say that we might sit at anchor with the boat off listening to music with our anchor light on and maybe an interior house light on.
Am I better off with 2 of the deepcycle combination batteries that are identical?

[Threeweight]

The way your boat is set up, it sounds like everything runs off one battery at a time.  So you are either running off battery #1, or battery #2, or they are combined.

I'm not a fan of that set up, but if you want to stick with it for now I'd get a couple of combination deep cycle/starting batteries.  Costco's prices are hard to beat.  You probably don't need a lot of CCA/MCA for you application... I'd try to find something with 525 CCA or better.

I had that same switch on mine, and I replaced it with a Blue Sea "add-a-battery kit.  My switch options are "on, off, combined".  When on, the engine is connected to one battery, the electronics to the other.  The kit includes an auto charging relay which allows the main motor to charge both batteries when running, but that keeps them isolated when there is no charging source.  With this set up, I like to run one starting battery, and one deep cycle.

[jamaica]

3wt... did you use the mini add-a-charger or the 120amp one? It appears to me that the mini should be ok and save some $.

[GregE]

Mini will be fine for Arima size applications

[jamaica]

Thanks Greg

[Yachter Yat]

   Switching and charging notwithstanding, I'd go with two deep cycle batteries.  The potential for my boat battery to get drained to lower levels than in my vehicle is what worries me.  I don't think draining cranking batteries is ever a good idea.  I replace my Sears Marine/RV deep cycle Die Hard every three years.  Need it or not, it gives me piece of mind.  I get a small trade-in allowance to boot.    :twocents:

   BTW, Shack, if your reading this, make sure you join Boat US.  You can do this on line or probably at West Marine up in Seabrook.  Cheap insurance.

Yat

[milos dad]

My Honda main only has a 6 amp charging system, and as I have added an electric Scotty downrigger, I am also installing the Blue Seas add-a-battery kit, with 2 deep cycle marine batteries.  I have isolated the starting battery from the house battery and the automatic charging relay will hopefully keep both batteries charged, or allow to 'combine' if needed.  I also bought a Costco lithium portable jump start kit, should I be unable to start the main via the battery combine function.  My kicker is manual start, so hopefully that would provide alternate mobility, albiet somewhat slow.  For redundancy, a manual start kicker with a charging system would be ideal.

M D

[Shackleton]

   Switching and charging notwithstanding, I'd go with two deep cycle batteries.  The potential for my boat battery to get drained to lower levels than in my vehicle is what worries me.  I don't think draining cranking batteries is ever a good idea.  I replace my Sears Marine/RV deep cycle Die Hard every three years.  Need it or not, it gives me piece of mind.  I get a small trade-in allowance to boot.    :twocents:

   BTW, Shack, if your reading this, make sure you join Boat US.  You can do this on line or probably at West Marine up in Seabrook.  Cheap insurance.

Yat

Yat - I do have the towing and Insurance through boat US.  The batteries that I pulled off the boat were 2013 and 2014 so I am probably overthinking things as the previous owner must have been all set for at least a couple of years with the set up the way I found it. I do plan on replacing them regularly.

[Threeweight]

Mini is fine for a 4 cylinder Arima-sized motor.  I went full sized because the 225 on my new boat can put out 90 amps.

Deep cycles and starting batteries are designed to do different things.

A deep cycle is designed to be slowly discharged, and can be drained very low and recharged with minimal effects.  Quality/power is usually measured in amp hours, which gives you an idea of how long it can run your downriggers, fish finder, etc...  Starting batteries are designed to put out a big burst of power quickly, in order to overcome the compression of you motor when you are trying to start it.  Quality/power is usually measured in cold cranking amps (CCA) or marine cranking amps (MCA).

If you look at the cold cranking or marine cranking amps rating on a deep cycle, they will typically be considerably lower than a starting battery or a dual purpose battery.  A starting battery on the other hand won't last long if you use it for power down riggers and drain and recharge it repeatedly.

AGM's are often the best of both worlds.  A good dual purpose AGM will often have more amp hours than a dedicated deep cycle, and more cranking amps than a starting battery.  Also sealed, so no risk of acid leaks that are possible with a flooded cell battery.  Of course, more $$$.

[T-Rex]

What Engine  ?
You should look up the Required CCA & Amp Hour Capacity for your engine first..... when you shop you will at least know if they meet the manufacturers specs or not....

[Shackleton]

2008 Honda 150 HP 4 stroke.  I'll check

[Full-Pull]

FWIW, the Blue Sea "Mini Add-A-Battery Kit" is intended for 65A Max charging systems.
The Blue Sea Standard "Add-A-Battery Kit" is intended for 120A Max charging systems.

https://www.bluesea.com/products/category/35/89/Add-A-Battery_Kit

According to the following link, the '08 BF150 has 51A charging output:

http://www.nielsens.com/new_vehicle_features.asp?veh=64572&CatDesc=

So the "Mini" should be fine for your application.
51A sounds about right for that size motor - But I'd definitely double check with a dealer, OEM manual, etc.

[DevMah]

Gents to add to threeweights comments.

There are two different types of lead acid battery, Starting and Deep Cycle. If a starting battery is routinely deep cycled (discharged below 20%-50% of max capacity) it will generally fail after 30-150 cycles. The same starting battery will last for thousands of cycles if it is just used normally.

A starting battery is designed to start a combustion engine (car, truck, boat etc). Inside a starting battery it will have more plates, thinner and often made of a lead "sponge" (looks like a foam sponge). This gives the plates more surface area in the solution than a Deep Cycle battery this allows them to draw larger currents much quicker than a Deep Cycle battery. Also allows the battery to recover faster between heavy draws and recharges faster.

A deep cycle battery has much thicker plates and they are solid. These thicker plates have less surface area so less of the instant power that a starting battery has. Deep cycles can be discharged down to 20% of their maximum charge repetitively with no damage to the battery.

You can use a Deep Cycle battery as a starting battery provided that you take into account the lower CCA of a Deep Cycle battery. As a rule of thumb it's a good idea to upsize the battery by about 20% to deliver the same amount of cranking amps from a deep cycle battery.

The starter draw on your engine will be around 150-200A, as mentioned above you have a 51A charging output. All you have to do is figure out your draw for your accessories then get a battery suited for your application. Here is a link to a calculator https://www.batterystuff.com/kb/tools/calculator-sizing-a-battery-to-a-load.html

FYI:

Cold Cranking Amps (CCA) is an indicator of the amount of current a battery can deliver for 30 seconds at zero degrees Fahrenheit without dropping below 10.5 volts.

The Amp Hour (AH) specification provides a measurement of battery capacity.  In other words, it is an indication of how much energy can be stored by the battery.

Tight Lines
Dev

[rasslingref]

Thanks for that simple explanation DevMah


Sent from my iPhone using Tapatalk

[DevMah]

Forgot to mention that combo starting/deep-cycle batteries are a bit of both worlds.

Hard to ague the advantages of Absorbent Glass Mat (AGM) Batteries only disadvantage is cost.

Keep in mind a poorly maintained battery (overcharging or under charging) regardless of being flooded or AGM will have the same end result.... premature failure.

Tight lines
Dev