How much "CCA" do I need on my starting battery?

[afsigma21]

Is 550 CCA enough? (625)

I was going to switch my batteries to a Deep Cycle House battery and a Dual Purpose for the starter, so when my Deep Cycle is drained because I play the stereo too loud too long, the starting battery had some capacity.

When researching, the DP battery is barely more CCA then the DC. Can I use the DC as both batteries?


Dealer gave me 2 starting batteries, I have not had a problem, just want to do the upgrade before I get to a failure.

Stock 212 Ltd S with a single Rockville 800w amp wired to the house battery. Plan to add a GPS and VHF in the near future.

I think it will be OK, just wanted some other opinions.

2x
https://shop.advanceautoparts.com/p/autocraft-marine-battery-group-size-24m-550-cca-24dc-1/2080060-P

or 1 of those and 1 of
https://www.batteriesplus.com/productdetails/sli24mdp

lowest price combo is 2x the Autocraft

 

[biffdotorg]

CCA on a pair of waverunner engines is less than minimal. You will be just fine especially when you compare the batteries you are looking at to the batteries installed in a waverunner using the same engine which are 200-270cca. You will not have an issue with your plan. But you are right, get the electronics off of a cranking battery.

Good luck

 

[2kwik4u]

Do charging amps available relate the same way between a traditional I/O and the smaller jet motors? What is a reasonable expectation for "recharging" the system? Can we just run around the lake for 20-30min to recharge the system?

I'm running a TINY electronics setup (stock AR190 head unit and speakers with 200W Class D amp in the sound bar. I only have a single starting battery that the dealer installed for me, no idea on the rating. I throw it on a Battery Tender after every outing just to keep it topped off, but is that something I really need to worry about?

I have considered running a "small" AGM battery for starting purposes, and replacing the stock battery with a deep cycle. Any thoughts on those types of batteries?

 

[Mainah]

I could write half a book on this topic but will keep it simple. If essentially stock audio system and no ballast pumps and no extended float times with the radio on then a standand start and marine deep cycle setup will do the job. Anything other than that AGM batteries are the best for boats in our price class IMO. Size right for your needs as going bigger than needed adds uneeded weight and cost.

In high end boats the debate is not between start, deep cycle, and AGM anymore. It is now between AGM and LFP. LFP aka lifepo4 aka lithium iron phosphate and sometimes confused with lithium ion produce twice the useable amps at half the size, half the weight, 3 times the life span, and significantly less volatge drop. The issue is the cost being 3x AGM for same useable amps if no sustained high discharge is needed (.2c to 1c) and 5x for sustained high discharge (2c to 5c). Most of us are not going to drop $1k on a 100ah high sustained discharge rate LFP though.

 

[Jgorm]

Imo agm is only worth the cost if you operate in very hot areas, batteries are located in a difficult to reach area, and leave the boat unattended for long periods. Agm usually had less Ah than lead acid for the same group. If you keep lead topped off they work just as well. Agm shines on things like jetskis and dirt bikes where tipping over is a possibility. My boat has lead acid. Waverunner has sealed lead acid (i don't think it's agm). Rv has lead acid Trojan deep cycle, mustang has agm, Jeep has agm, but it's dead and I'm going back to acid. Agm is usually near double the price. Make sure you really need it. They don't have more power, and they don't last longer. They do take serious abuse a little better, but it's better to not abuse then! I have 12 batteries between all my vehicles and I've had lots of lead and agm failures over the last 10-15 years. The single most important thing for battery life is a quality 2 or 3 stage charger with a 13.0 v float. If you don't drive it every week it should be on a charger.

 

[2kwik4u]

Sounds like I don't need to change a thing then. I have a relatively small stereo, not many other loads, and not overly long run time. It sits on a tender in the garage between outings.

We did run the stereo fairly loud with the soundbar fairly loud a few weeks back. I checked the voltage every few hours, and ended up starting the boat once to bring the voltage back up. Essentially let it idle for about 10-15 minutes while I got a drink and made a sandwich. No idea if that was really necessary or not, but made me feel better. Let the stereo run for another 4.5hrs after that and it still started like nothing happened.

What wattage of stereo should I start looking at a house battery? Currently have the stock head unit powering 4 POS speakers, maybe 45w total there? Then the Soundbar with a 200W internal amp running. Would like to upgrade the cockpit speakers to something a little nicer (Pold DB65's seem to be popular), and then an accompanying amp to drive them. Will that warrant the upgrade to a second battery and associated cabling and switch? What about just getting a jump pack to restart at the end of the day? Any rules of thumb for when to upgrade the power bank?

 

[biffdotorg]

We did run the stereo fairly loud with the soundbar fairly loud a few weeks back. I checked the voltage every few hours, and ended up starting the boat once to bring the voltage back up. Essentially let it idle for about 10-15 minutes while I got a drink and made a sandwich. No idea if that was really necessary or not, but made me feel better. Let the stereo run for another 4.5hrs after that and it still started like nothing happened.

Keep in mind, these motors have a stator, just like the Yamaha outboards. So unlike a true alternator, they are not generating much current at idle. You gotta get the RPM's up to generate anything. That being said, you may not have drained it all that much to have any impact.

My buddy's 150hp Yamaha Outboard (with stator) will actually draw more power at idle than it can generate. So it actually depletes the battery at idle. My Yamaha 4-cylinder and 3-cylinder sleds will not warm up the grip heaters until they come off idle. We used to add boosters that would draw from the battery to warm up the handlebar while warming up the engine. As the system would not put out enough current during warm up. Nothing like leaving in -15f with cold handlebars.

Textron's new Yamaha powered Wildcat XX has an alternator option for those adding stereo, gps, light bars etc. As the stator on the Yamaha 998cc triple will not put out enough juice to maintain the battery.

Good luck!

 

[Weeb]

I could write half a book on this topic but will keep it simple. If essentially stock audio system and no ballast pumps and no extended float times with the radio on then a standand start and marine deep cycle setup will do the job. Anything other than that AGM batteries are the best for boats in our price class IMO. Size right for your needs as going bigger than needed adds uneeded weight and cost.

In high end boats the debate is not between start, deep cycle, and AGM anymore. It is now between AGM and LFP. LFP aka lifepo4 aka lithium iron phosphate and sometimes confused with lithium ion produce twice the useable amps at half the size, half the weight, 3 times the life span, and significantly less volatge drop. The issue is the cost being 3x AGM for same useable amps if no sustained high discharge is needed (.2c to 1c) and 5x for sustained high discharge (2c to 5c). Most of us are not going to drop $1k on a 100ah high sustained discharge rate LFP though.

Lithium makes me nervous with all the toys phones and ecigs blowing up. I have a lithium jump starter I’m afraid to leave on the boat.