Starting battery

kappykaplan · Jul 9, 2023

fred1diver said:
could it be because I used a deep cycle as a starting battery?

No.

dlochner · Jul 9, 2023

fred1diver said:
could it be because I used a deep cycle as a starting battery?

No.

fred1diver said:
What would you suggest as a good starting battery?

A good deep cycle battery.

What is a Deep Cycle Battery? - Marine How To

Light Cycle vs. Deeper Cycle NOTE: This article deals with FLOODED marine batteries, not AGM or GEL batteries. The Problem: The problem, as I see it, is one of dishonest marketing where multiple battery types wear the same clothes (sticker) and will perform differently when

marinehowto.com

Automotive Alternators vs. Deep Cycle Batteries - Marine How To

A Deep Cycle Battery Assassin The alternator pictured here helped to destroy a very expensive bank of TPPL AGM batteries in under two years. These batteries need an absorption voltage of 14.7V. The highest voltage I recorded on this vessel was 13.58V at the battery terminals. At this

marinehowto.com

Davidasailor26 · Jul 9, 2023

What are you doing to keep the batteries charged? It’s much more likely that charging routine or excessively deep discharges are at fault.

Don S/V ILLusion · Jul 9, 2023

Davidasailor26 said:
What are you doing to keep the batteries charged? It’s much more likely that charging routine or excessively deep discharges are at fault.

Good point!
If a battery doesn’t last as long as it should, the problem is generally caused by improper charging.

dlochner · Jul 9, 2023

Don S/V ILLusion said:
Good point!
If a battery doesn’t last as long as it should, the problem is generally caused by improper charging.

Or discharging too deeply and/or too often.

Don S/V ILLusion · Jul 9, 2023

dlochner said:
Or discharging too deeply and/or too often.

Unlikely on a ‘start’ battery.
How are the batteries interconnected for charging?

Scott T-Bird · Jul 9, 2023

fred1diver said:
I will probably switch from deep cycle (only one at the moment for the house bank) to golf cart batteries.

Golf cart batteries are very good deep cycle batteries. If you don't describe your charging circumstances, nobody can help you - besides, we don't even know what batteries you installed. How do you know one battery is going bad?

capta · Jul 9, 2023

Golf cart batteries are very heavy. And pretty expensive. And have a limited number of charging cycles.
If you intend to keep this boat for at least 5 years or so, I would suggest that you consider LifePO batteries. They are worth every penny of the extra money, if you care for them properly, and they should cost you less in the end, as they will outlast LA batteries many times over.

Tally Ho · Jul 9, 2023

I use two Duracell 6-volt Golf Cart batteries I picked up at Sam’s Club for about $150 each…

These 2 batteries serve as both my house batteries and they start my engine. They give me about 215 AH @12 volts.

They are about 3 years old now, used 6 months a year, and left on the boat over the winter.

I do plan to add a starting battery on a separate circuit at some point so I don’t find myself out on the hook for a few days and find out I don’t have enough juice to start the engine. But I have been out for a few days, and haven’t had a problem yet.

My boat is on a dock with power and I am mainly day sailing, so my batts are fully charged every day.

Cheers And good luck,

Greg

FastOlson · Jul 9, 2023

Our battery usage is similar to Greg. On the shore power charger all the time unless out sailing or gone for a month cruising.
My previous bank of two Trojan T-145+ batteries lasted 9 years, and the current bank of same model batteries is now getting replaced because they will not charge up all the way. They are about 7 years old.
While I would probably like some new high-tech batteries, I would have to change our alternator to an external-regulated model. And.... our present "old" flooded technology meets our needs. We do use our 260 AH house bank for everything including starting our 25 hp diesel. I have a reserve 'emergency' bank of a single 12 v. AGM which we test out several times a year.
Keep us posted on the battery replacement. I find that the present high price of lead has doubled the cost of batteries. Bit of a "sticker shock" , as they say.
Oh well, maintaining a sailboat is another First World Problem, as the saying goes!

Ward H · Jul 9, 2023

Similar to Greg I installed two Duracell 230AH batteries in 2018 at a cost of $115 each for my house bank.
I when not sailing Im on shore power with the batteries being charged with a 30A Sterling Procharge charger.
I leave the batteries on the boat each winter after fully charging them, then disconnecting completely.
It takes about a month of use for the SG200 monitor to report State of Health at 100% after being disconnected each winter.

My start battery is a standard "deep cycle" Grip 31 FL battery installed in 2017. It handles starting my M25XP just fine and can back up my house bank if ever needed.

For my use true deep cycle FLAs work well for my use.

dlochner · Jul 9, 2023

fred1diver said:
2 bank 10 amp charger does what is expected.

This may be part of the problem. A 2 battery 10 amp charger will only provide 10 amps of charging, meaning if both batteries need charging they will each get 5 amps or less.

Benny17441 · Jul 9, 2023

No, not for using as a starter battery for a small diesel auxiliary engine.. Many batteries die a premature life while others seem to live forever and the manufacturers have no clue why is that so. This is the reason for the different warranty plans they all offer. You are basically purchasing a set length of power service. The same battery is basically sold with different labels from Standart to Gold Premium Deluxe depending on the terms of the warranty plan and the price option you choose. Take the battery back to the dealer so they can run a diagnostic on it and get a replacement or a prorated allowance according to the terms of the warranty. Do your homework and read up on batteries and how to best maintain them. Two things are very important 1) Promptly recharge batteries back to 100% capacity after every outing. 2) Do not discharge a battery deeper than 50% of its rated capacity in Amps. A 10 Amp charger is fine as long as you are not running any concurrent loads and allow for the additional time to get both batteries to 100% capacity.

dlochner · Jul 10, 2023

fred1diver said:
Just came back from getting the battery checked, they say it is still in excellent condition, but it doesn’t give me much power, I don’t get it.

Battery testers are not all that accurate. Based on voltage alone the battery could near its end of life but still show good voltage. The most accurate measure is a 20 hour discharge test. A load equal to 5% of the nominal amp hour capacity is attached to the battery. A battery with full capacity will take 20 hours to reach 10.5 volts. If the battery reaches 10.5v in 10 hours it only has 50% of its capacity.

Battery capacity, the number of amp hours available is a function of the amount of clean lead on the plates. As batteries age lead sulfate forms on the plates and essentially insulates them from the electrolyte and makes the lead unavailable to produce current. Each cell in the battery still produces the same voltage, but the capacity becomes diminished.

The two biggest causes of a battery's early demise is discharging the battery too deeply and undercharging. Deep discharging, below 50% of capacity (state of charge) allows too much lead sulfate to form. Undercharging at too low a voltage or too low a current does not provide enough energy to reverse the sulfating process, thus not enough sulfate is removed to restore the battery to full capacity although the voltage appears fully charged.

Flooded Lead acid batteries generally like to have an absorption charge of around 14.8v and at 10-15% of their amp hour capacity. A Group 24 battery has an amphour capacity of around 70-75 ah. Charging current should then be between 7 and 12 amps doing the bulk stage. A Group 27 battery has around 90 ah and a group 31 around 100 ah.

This is just a quick over view of the issues. Take a look at the articles I posted earlier.

Don S/V ILLusion · Jul 10, 2023

fred1diver said:
Just came back from getting the battery checked, they say it is still in excellent condition, but it doesn’t give me much power, I don’t get it.

How did they test it? Magic wand?

Johnb · Jul 10, 2023

Don S/V ILLusion said:
How did they test it? Magic wand?

You apply the leads of your battery tester, read the voltage, then press the button and get a reading of the cranking amps. Takes about 2 seconds.

To the OP I suggest you clean and tighten all connections. If any one of them is dirty or loose all of them were due for TLC also. If that fixes your problem mazeltov. If not time to get scientific.

Davidasailor26 · Jul 10, 2023

Johnb said:
You apply the leads of your battery tester, read the voltage, then press the button and get a reading of the cranking amps. Takes about 2 seconds.

Yep, that’s pretty much how it’s usually done, but that’s not necessarily an accurate indicator of a battery’s ability to provide many amp hours over an extended period. The quick test shows how much current the battery can deliver. For an actual deep cycle test the 20 hour routine dlochner recommended is more reliable.