What Starter Battery???

Nov 13, 2020
57
Hunter H34 Chesapeake Bay
When I bought my H34 a few months ago it came with two Season All deep cycle batteries. After letting things play out for a few months, I’ve decided to buy a starter battery. For those of you whom have a dedicated starter battery, what group and brand do you have, and are you happy with it?

I’ve used Optima Red tops in my vehicles for 20 years. However, I’m hoping to learn something here about boat batteries.

thanks,

John
 

Ward H

.
Nov 7, 2011
3,129
Catalina 30 Mk II Barnegat, NJ
A deep cycle battery works fine as a dedicated starting battery. There is no advantage to buying an automotive type starter battery.
Here is a good article on deep cycle batteries. What is a Deep Cycle Battery?

The short story is our diesels start fine on a deep cycle battery. They are made for deep discharging where as auto starter batteries are made to put out a lot of juice and be recharged quickly.
This allows a dedicated deep cycle starter battery to be a good back up for your house bank but a starter battery will not as they are not designed for deep discharge.
Deep cycle batteries have thicker lead plates, withstand more abuse and will last longer than automotive starter batteries.

Many boaters think they need a "starter" battery for starting their diesel inboards but a deep cycle battery offers a lot of benefits.

Here is a link to the forum with several good threads on electrical and batteries. Musings With Maine Sail
Check out the 2nd (on battery switches) and 4th (AGM Batteries) pinned threads.

Hope this helps.
 
May 24, 2004
6,793
CC 30 South Florida
As far as starter batteries they are the same as used in cars. The boat can use a smaller battery as the starter will require less cranking amps than the usual power hungry automobile. I have experienced that the best battery is the one with the best and longest warranty. I recommend that you purchase your battery from a national retailer as when travelling you can redeem the warranty anywhere. Even the top manufacturer batteries can die prematurely and that is why they all offer warranties which by the way you pay for. The secret to long battery life besides buyers luck is in the maintenance. Charge them back to full after every use, maintain the acid solution level and keep the poles clean and the connectors tight. In hot humid weather check the acid level more frequently. You will have to decide how you are going to recharge the battery whether exclusively from the alternator or a dual source of alternator or inboard battery charger. The problem with sailboats is that we crank the engine ON but then don't run them long enough to recharge the battery fully. Because of battery chemistry even a small discharge will require an hour or two of charge. By installing an Echo Charge at around $130 you could charge both the starter and house bank simultaneously with a suitable inboard charger. Just food for thought, do what will work best for you.
 
Feb 14, 2014
5,710
Hunter 430 Waveland, MS
I bought a Walmart special , lead acid, for my size engine, 50 HP.
They replaced one free.

My Start Battery also powers my 1500 lb electric winch and windlass. Deep Cycle is only used in a pinch.

Jim...
 
Nov 6, 2006
9,225
Hunter 34 Mandeville Louisiana
Probably should be the same type battery because the charger might get confused and overcharge//undercharge one or the other.. a dedicated start battery is unnecessary on the H-34 .. even with a much depleted bank, the engine can be decompressed, spun by the depleted battery and it will start when the decompress levers are flipped back on. or if that makes ya nervous, a small jump pack will crank the engine.
 
Jul 7, 2004
8,013
Hunter 30T Cheney, KS
Probably should be the same type battery because the charger might get confused and overcharge//undercharge one or the other..
That would be my input. have a 2 batt Home bank and a 1 batt Start bank. All the same deep cycle type
 
Feb 6, 1998
11,436
Canadian Sailcraft 36T Casco Bay, ME
On a boat with a second bank try not to think of it is a "starting battery". It may some day be your "start/reserve/emergency" battery! For this reason a deep-cycle battery will not only last longer, more robust build but will also have way more than enough amps to start your engine and be used as a reserve/emergency bank when or if you may need it. Use a start battery as a deep-cycle bank, even once, and it can suffer permanently..
 
Nov 13, 2020
57
Hunter H34 Chesapeake Bay
Thanks everyone for the responses. I'm aware of the ideology on MarineHowTo.com regarding using deep cycles in lieu of a starter type battery. It was for that reason I chose not to install a starter battery when I first bought the boat. I figured I'd give it a try and see how it played out. It seemed fine until last weekend when my engine didn't start after about 10 seconds of cranking. When I attempted to start it a second time, there wasn't enough juice to crank it over. I checked the battery voltage and it was at 12.5. Fortunately, I had a portable battery pack that I put on it and was able to start the engine. My experience has been that in a perfect world, the deep cycles would probably be sufficient. However, I do not live in that world. It seems that if the engine doesn't start right away, the deep cycles don't have enough cranking amps for a second attempt. It is for that reason I've decided to install a starter specific battery and use the two deep cycles for the house bank.
 
Feb 6, 1998
11,436
Canadian Sailcraft 36T Casco Bay, ME
Thanks everyone for the responses. I'm aware of the ideology on MarineHowTo.com regarding using deep cycles in lieu of a starter type battery. It was for that reason I chose not to install a starter battery when I first bought the boat. I figured I'd give it a try and see how it played out. It seemed fine until last weekend when my engine didn't start after about 10 seconds of cranking. When I attempted to start it a second time, there wasn't enough juice to crank it over. I checked the battery voltage and it was at 12.5. Fortunately, I had a portable battery pack that I put on it and was able to start the engine. My experience has been that in a perfect world, the deep cycles would probably be sufficient. However, I do not live in that world. It seems that if the engine doesn't start right away, the deep cycles don't have enough cranking amps for a second attempt. It is for that reason I've decided to install a starter specific battery and use the two deep cycles for the house bank.
If the batteries are healthy, a deep-cycle house bank will easily out crank a single starting battery even at 50% SoC.. (this is not made up or theoretical but rather real world data). If the bank has been abused, has poor wiring, terminations etc. then that would be true for any type of battery. Keep in mind that most "deep-cycle" labeled G-24, 27, 29, 30 or 31 batteries have very similar construction to a cranking only battery only with thicker grids, better envelopes etc... When you place two or more house batteries in parallel the single start battery can't hold a candle to them. Here in the shop we started a large Yanmar over 40 times on a single deep-cycle battery with zero charging in-between. My guys finally got bored and stopped... If your deep cycle battery dies after 10 seconds of cranking, it had some major issues.

Heck the batteries for all our heavy equipment up North, a Cat D3 dozer (12V), Cat 320L excavator (24V), 40HP Kubota (12V) and a F550 dump body (12V) are all used marine deep-cycle batteries that still had life left in them when the owners upgraded to AGM, GEL or even LiFePO4. We've never once had a non start issue. We've had to crank the D3 quite a bit to bleed the system and the used DC batteries still pulled it off. The Kubota is the same exact engine used in boats. It has had a single used group 24 deep cycle battery in it for 3 years now and we run that tractor year round often starting in in below 0F temps.. In a starting only application I can get about 3-5 more years out of these batteries, and they're free.
 
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Ward H

.
Nov 7, 2011
3,129
Catalina 30 Mk II Barnegat, NJ
While checking battery voltage can give you an idea of state of charge, it can also give you a false reading if the voltage is read with no loads on the battery.
Try checking the voltage with several loads turned on or while cranking. If the battery cannot maintain voltage with loads applied the battery is probably bad.

Kind of like getting in your car, turning the key to run and dash lights, interior lights, etc come on. You try to start the engine and the lights dim and the engine won't crank.
 
Feb 6, 1998
11,436
Canadian Sailcraft 36T Casco Bay, ME
While checking battery voltage can give you an idea of state of charge, it can also give you a false reading if the voltage is read with no loads on the battery.
The open circuit voltage has no direct comparison to state of health of the battery. I can't even begin to tell you how many deep-cycle batteries we've run 20 hour tests on, that can deliver a perfect 24 hour resting voltage of 12.72V or higher, and that will still pass specific gravity readings perfectly. Some of these even pass a Midtronics test! When tested doing a 20 hour test to BCI standards, they can't even deliver 30% of their rated Ah capacity..

This post is a prime example of this: How to Murder Batteries in Half a Year


Try checking the voltage with several loads turned on or while cranking. If the battery cannot maintain voltage with loads applied the battery is probably bad.
The best way to do this is with a DVM that can record or "hold" a peak low voltage. Simply clip it to the battery terminals, set peak hold (not all DVM's can do peak low hold) and hit the starter. Now check the peak low voltage..
 
May 19, 2020
65
Hunter 30 Quincy
I've got a cheap Costco group 31 battery isolated from my main house battery and charged via an ACR. I followed Marine Sails' instructions and replaced some of the existing wiring (good experience with Genuine Dealz, cheesy name but their stuff appears to be good quality).
My engine is a 2GM20F
I would've gone smaller but the G31 battery was the smallest I could find that was still a dual purpose which I wanted as it's my "backup" house cell, not that I intend to ever use it as such.
 
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