May we discuss start batteries?

My current setup:


Twin yanmar 4lha-stp, 240 hp.
Single 4D start battery, West Marine dual purpose, FLA (5 years old and dead)

House bank is 4 6V GC batteries, FLA (6 months old)
Banks are connected via an ACR. 50 amp shore power charger.



My start batt has recently bitten the dust and is no longer holding a charge. The 4D has worked pretty well, but they are sort of uncommon, expensive and heavy. Also, I'd like an actual start battery rather than a dual purpose. I looked but couldn't find a 4D start battery when I put this one in 5 years ago.


I'm not real happy with the longevity of this battery, it leads an easy life, not sure what caused such an early demise.



I'm considering going to a group 31 start battery. CCA are very similar, it's 1/2 the cost, easier to install and takes up less space. I reckon that if needed I could always get a second G31 and parallel it, cost of two would be about the same as one 4D.


Any thoughts? Any idea how many amps I need to crank my motors?


Thanks!

Check out this link for recommended starting battery: https://shop.toadmarinesupply.com/s...finalcrumb=Yanmar+Marine+Battery+Requirements

As always...double check with Yanmar's operators or service manual for your engine.

A good grp 31 should do the job just fine. I use a single grp 31 to start my 8.3liter engine which is more than twice the size of your Yanmars. It starts fine down to an engine room temp of about 40-45F, the coldest it gets here. I have a manual switch to parallel it to the house bank, but have not needed to.

I'd say go grp 31, but have a way to parallel it to your house bank if needed.

I'm pondering a different path...

We have a GB70 Genius Boost jump start battery and it's got me thinking about doing away with a starting battery altogether. It's easily recharged via the 12 volt cigarette lighter and with a full charge will supposedly start 40 diesel engines larger than our Yanmar 4JH2.

Interestingly, we have the same house and starting battery set up as yours. If there's any logic to my idea we should be able to keep the same 100 amp alternator, increase the size of the house bank by 25% to 50%, have only one simple ON/OFF switch, get rid of three 1/2/ALL/OFF switches and probably dozens of feet of wiring.

Crazy? Maybe...

My boat has 2 4D start batteries, probably overkill but the box is glassed in and would be a lot of work to change it. Last year one of them went bad so I replaced both with Interstate 4Ds. They were supposed to be starting batteries but I don’t remember the model number right now. If CSR disease doesn’t kick in I will check tomorrow and see what model they are.

My Cummins 6B engines have OEM a 8D starting battery for each engine.
The 8D battery has approx 1400 CCA rating (interstate batteries)

My Cummins 6 cyl diesel powered pickup has two group 65 batteries which have 750CCA each as a OEM installation.

My thought is that two different manufacturers opinions of the battery recommendation for a Cummins B series 6 cylinder engine result in 1400-1500 CCA.

I think I’ll stick with their recommendatons.

Starting batteries -- one 4D compaird to couple Group 31's

------- BOAT Starting batteries. -- a discussion.

The 4D's & even 8D's are batteries that are very heavy to handle at way over 120 + lbs. or more each & who needs the aggravation of finding someone to help you move them around.
.
The big rig trucks & many boaters today are now going to a Group 31 battery & never look back. -- SKI in NC know what he is talking about.

There are a lot of good group 31 starting batteries with built in Stud terminals so no post adapters needed with up to 1,000 CCA's on tap and still priced very reasonable & if your really worried, put two in parallel & have more than you ever had with the 4D for your starting battery.

Newer technology that has been introduced in the Group 31's & is a big step above the 4D's & are cheaper, easier to handle, take up less space, have better warranties, and last just as long, if not longer.

OP - Doug Cole said "

I'm considering going to a group 31 start battery. CCA are very similar, it's 1/2 the cost, easier to install and takes up less space. I reckon that if needed I could always get a second G31 and parallel it, cost of two would be about the same as one 4D

Click to expand...

." - and your thinking process stated above is right on target
. ----- There is no down side ---- ! -
---------------------- Make the move to G31's. --------------

I have converted my Kadey-Krogen 42 to all group 31 batteries for all my battery needs - be it usual starting, typical house deep cycle & Thruster AGM's & have not regretted it.
---- In fact, I would never go back - it is that much better.

There is a good wide range of selection of different levels & types of G-31's out there, at every price point & quality level & battery type, so shop around & do your homework.

My recommendation is to go that route.

Good Luck with your project.

Alfa Mike

Our boat (twin Lehmans) has a house bank of eight golf car batteries, no separate starting battery. Those engines start in 1 or 2 seconds. I see no need for engine starting batteries in my case. However, I do have two Group 27s to start either of the two on board generators that could be used to start the engines in the highly unlikely event that the house bank was far too depleted. I once started the engines easily when I depleted the house bank to 20%. The two Group 27s for the generators is overkill. One would suffice. Charging is through a Blue Seas ACR.

Dougcole said:

My current setup:


Twin yanmar 4lha-stp, 240 hp.
Single 4D start battery, West Marine dual purpose, FLA (5 years old and dead)

House bank is 4 6V GC batteries, FLA (6 months old)
Banks are connected via an ACR. 50 amp shore power charger.



My start batt has recently bitten the dust and is no longer holding a charge. The 4D has worked pretty well, but they are sort of uncommon, expensive and heavy. Also, I'd like an actual start battery rather than a dual purpose. I looked but couldn't find a 4D start battery when I put this one in 5 years ago.


I'm not real happy with the longevity of this battery, it leads an easy life, not sure what caused such an early demise.



I'm considering going to a group 31 start battery. CCA are very similar, it's 1/2 the cost, easier to install and takes up less space. I reckon that if needed I could always get a second G31 and parallel it, cost of two would be about the same as one 4D.


Any thoughts? Any idea how many amps I need to crank my motors?


Thanks!

Click to expand...

IF you are a warm area boater a single quality GP 31 should be fine.

If you need to start around or below freezing with no block heater a pair would be a better choice.

Thanks for all of your replies everyone. I think I'm going to go with a group 31.

We have a simple set up like Catalina Jacks. 4 golf carts are both house and starting. Normally run them as a single bank but can split for fast charging with a 50 amp inverter/charger and 50 amp stand alone charger. Never a problem starting the single 3116 CAT. Generator has it's own group 24 starting battery.

Personally I don't like the combined house / start setup. Not so much for lack of starting power (rarely an issue if the house bank is big enough), but because of the voltage dip all of the electronics see during engine start. Better to keep that isolated when possible.

I've got 3 banks personally. House (2x L16), Start 1 (grp 27), Start 2 (grp 27). House is isolated from both start banks, connecting them would require jumper cables. So house is an on/off switch. Each engine and the generator has a 1/2/both/off switch to select its power source. Normally the port engine starts from Start 1, starboard and the generator are set to use Start 2. Makes it hard to end up in a situation where I can't get something started and it also keeps house loads separate from cranking current.

Dougcole said:

Twin yanmar 4lha-stp, 240 hp.
Single 4D start battery, West Marine dual purpose, FLA (5 years old and dead)

I'm considering going to a group 31 start battery. CCA are very similar, it's 1/2 the cost, easier to install and takes up less space. I reckon that if needed I could always get a second G31 and parallel it, cost of two would be about the same as one 4D.

Click to expand...

Dougcole said:

Thanks for all of your replies everyone. I think I'm going to go with a group 31.

Click to expand...

Your Yanmar manual will specify minimum cold and marine cranking amps. I'd bet a single Group 31 would do it. You might compare brands, 'cause some offer higher or lower cranking amps.

Your engine alternators ought to keep the batteries charged. If you happen to chose AGMs, they don't self-discharge very much... but if easily servicaable, FLAs can be great value.

A parallel switch can be a good thing.

You could maybe consider a G31 for each engine. A parallel switch connecting those would operate independently of your house bank.

-Chris

If one is concerned with a voltage dip on start-up and its affect on electronics, simply start the engines, then turn on the electronics.

rslifkin said:

Personally I don't like the combined house / start setup. Not so much for lack of starting power (rarely an issue if the house bank is big enough), but because of the voltage dip all of the electronics see during engine start. Better to keep that isolated when possible.

I've got 3 banks personally. House (2x L16), Start 1 (grp 27), Start 2 (grp 27). House is isolated from both start banks, connecting them would require jumper cables. So house is an on/off switch. Each engine and the generator has a 1/2/both/off switch to select its power source. Normally the port engine starts from Start 1, starboard and the generator are set to use Start 2. Makes it hard to end up in a situation where I can't get something started and it also keeps house loads separate from cranking current.

Click to expand...

This is the 4Ds that I installed last year as starting batteries. I know they are overkill but the battery box is glassed into the hull and not worth changing it.

catalinajack said:

If one is concerned with a voltage dip on start-up and its affect on electronics, simply start the engines, then turn on the electronics.

Click to expand...

That's how I used to do it before I put in a separate house bank. But it's nice to not have to worry about it. Especially when picking up anchor where the plotter is already on (from being used for an anchor alarm), for example.

catalinajack said:

If one is concerned with a voltage dip on start-up and its affect on electronics, simply start the engines, then turn on the electronics.

Click to expand...

We have never had any issues with electronics and starting even though they are all on the same bank. Even the inverter never blips during startup. Might be because the CAT starts with just a touch of the starter each and every time.

My group 31 Lifeline AGM start battery has been flawless for the past six years, my house bank is a pair of Lifeline 4D AGM's. The house bank isn't running my Webasto heater except when the engine is running (last trip out only) and checking the voltage it isn't holding it's charge (only 12.55V). With an average of 5 months a season of hard running I think they have hit the projected lifespan of the number of cycles with 100 plus cycles a season and relatively deep discharges.

I am considering replacing the start battery as well as the house bank before the next season begins. There doesn't seem to be any issue with the start battery but it's hard to get to. My engine is also a Yanmar (4JH) and starts pretty much instantly when I hit the key.

AKDoug said:

My group 31 Lifeline AGM start battery has been flawless for the past six years, my house bank is a pair of Lifeline 4D AGM's. The house bank isn't running my Webasto heater except when the engine is running (last trip out only) and checking the voltage it isn't holding it's charge (only 12.55V). With an average of 5 months a season of hard running I think they have hit the projected lifespan of the number of cycles with 100 plus cycles a season and relatively deep discharges.

I am considering replacing the start battery as well as the house bank before the next season begins. There doesn't seem to be any issue with the start battery but it's hard to get to. My engine is also a Yanmar (4JH) and starts pretty much instantly when I hit the key.

Click to expand...

Geez Doug!

In your gorgeous Willard (yes folks I’ve seen it and it is flat gorgeous) your engine is about the same size as a garden tractor A group 31 is overkill. You could start that thing with a couple of old D cells strung together

"Personally I don't like the combined house / start setup. Not so much for lack of starting power (rarely an issue if the house bank is big enough), but because of the voltage dip all of the electronics see during engine start. Better to keep that isolated when possible. "

The simple seamless solution is to power the electronics from the ACC terminal of a auto style key switch.

Cole Hersey sells proper marine versions of this style key switch.

A simple relay might be requred if there are lots of electronics.