Batteries lasting only 2 years - AGM any better?

[purplesunrise]

If you are using multiple flooded batteries it is essential to have a good watering system with visual level indicators. We just installed the US Battery watering system on our 10 deep cycle 6 volt deep cycle batteries (1180 Ah) and it works much better than the Flowrite because we can the see the water levels.

[Compass790]

Sorry if I'm stating the obvious but have you tested to see if there is any drain on the batteries with everything switched off?> 2 years is not anywhere near right

[belizesailor]

Originally Posted by Caliber40

What was the voltage before you keyed the switch? A fully charged battery is 12.8 V and 12.4 represents approx a 50% charge. On a regular basis how often do the batteries go below 12.3V ? If often how low do you let them drop to that level.

Very possible you have a starter/solenoid issue. Some boats have too small of a connector wire from the ignition switch to the solenoid causing below satisfactory drop in voltage. I dont remember what engine you have but Yanmars are notorious for this.

If you are starting with a 12.8V battery and getting "clicking" I'm betting it's not the battery.

Good luck

My thoughts too, if its only drawing down to 12.4, then the problem is likely elsewhere. Starter solenoid or cable connections to start batt/starter are likely culprits.

Load testing the start battery would confirm whether that is an issue.

[Mike Banks]

I replaced my flooded cell tractor batteries every two years. They may have lasted longer--but that was the advice I was given by the commercial fishermen using the same system as I.
.

[arthur.watson.1]

Also, make sure your batteries have adequate electrolyte levels. If you don’t regularly replenish your battery fluids the batteries could dry out and will not perform for you.

[Compass790]

Originally Posted by Mike Banks

I replaced my flooded cell tractor batteries every two years. They may have lasted longer--but that was the advice I was given by the commercial fishermen using the same system as I.
.

If I was in Aus, I'd gladly take your old ones. The commercial fisherman probably gives his a much harder life but it depends on your system. If you are keeping them topped up with a solar panel they should do better than that even if they aren't deep cycle

[rosco4271]

Originally Posted by Caliber40

What was the voltage before you keyed the switch? A fully charged battery is 12.8 V and 12.4 represents approx a 50% charge. On a regular basis how often do the batteries go below 12.3V ? If often how low do you let them drop to that level.

Very possible you have a starter/solenoid issue. Some boats have too small of a connector wire from the ignition switch to the solenoid causing below satisfactory drop in voltage. I dont remember what engine you have but Yanmars are notorious for this.

If you are starting with a 12.8V battery and getting "clicking" I'm betting it's not the battery.

Good luck

I am an electrician I don't believe you have a battery problem, sticky solenoid sounds the most likely or the engaging gear is catching on the flywheel,
As a test get another battery and jumper it to the existing battery, if it still clicks it definitely in the starter, it could be you have a lazy solenoid any way It could be poor connection at the battery or at the starter solenoid, remove both clean the crimps and teminal posts with a wire brush and reinstall ensuring there is a good wide washer and spring washer over the crimp lug. I also put a washer under the crimp lug. Simple things are usually the issue.
Good luck

[Mal Reynolds]

Originally Posted by rosco4271

I am an electrician I don't believe you have a battery problem, sticky solenoid sounds the most likely or the engaging gear is catching on the flywheel,
As a test get another battery and jumper it to the existing battery, if it still clicks it definitely in the starter, it could be you have a lazy solenoid any way It could be poor connection at the battery or at the starter solenoid, remove both clean the crimps and teminal posts with a wire brush and reinstall ensuring there is a good wide washer and spring washer over the crimp lug. I also put a washer under the crimp lug. Simple things are usually the issue.
Good luck

^^This. Also try tapping the starter with a hammer to get the solenoid to unstick.

[Joe500]

Thanks to all for the suggestions. It sounds like many of you think the problem may not be the battery. So I just ordered an Ansel Ba101 digital battery tester on amazon so I can test the CCAs coming out of the battery. I also ordered some jumper cables (4 gauge, 20 feet) Cartman brand so I can easily connect the batteries to the solenoid without moving them. I guess shorter would have worked better but that's what they sell.

To answer some questions, the solar panel is hooked up to bank 1 and charges that bank all the time via the Victron MPPT. Charging bank two is harder. I can either switch both banks to "on" while the engine is running or while the solar panel is on. The boat has been unused for 18 months, so I just left both banks on all the time. This is probably a bad idea because the fully charged voltage on the starting battery is higher than on the deep cycle batteries, but without additional equipment that was the only easy way to keep both charged for a long time. All batteries are under the aft berth, right next to the engine which is located under the stairs.

The loads and cycles on these batteries when I did use them (for just one season in 2016) were not significant. We would only use the boat on weekends. Sometimes we would leave the refrigeration on for the weekend, which is old and draws about 6amps/hour, and that would discharge the batteries over a weekend, but I would watch the voltage and not discharge them too much.

The Victron saves a history of 30 days and I can tell you that recently the solar panel has been doing a good job keeping batteries charged with daily minimums of around 12.8 and maximums of 14.x. I can't remember exactly. In the winter these number are lower, probably between 12 and 13, I imagine just because it's colder and fully charged voltages are lower.

Joe

[Joe500]

By the way, there does not seem to be any loads draining the battery when everything is off. I have a battery monitor that I put in front of everything, and it records a daily history of loads.

The battery cables from batteries to switch are new. The cables from the switches to the engine may well be the originals, which would make them 30 years old. So based on the comments you all sent, I suspect those cables could be the problem.

[chef2sail]

Along with proper watering and the loads do you equalize you batteries and blow the sulfates off the lead plates. If not you may be suffocating them.

We have 6-6 volt Lifeline AGM . Our first bank lasted 10 years

[Zil]

You are killing your flooded batteries. You will kill the agm as fast. Only it will cost you more money. Batteries that are charged do not freeze.

[mikereed100]

I too think your problem is electrical, rather than batteries. You can check voltage drop simply by checking voltage at the solenoid while someone turns the key. If it is less than 90% of the voltage at your battery monitor, indicating a voltage drop of greater than 10%, you may have an issue with bad connections or undersized wire. The solenoid may have enough juice to "click" but not enough to make a good connection at the high amp terminals inside. Another easy test is to simply use a screwdriver to "jump" the solenoid from the battery terminal on the starter. If this turns the starter you know you have a wiring problem and that the solenoid is OK. Be sure your engine compartment is well ventilated before doing this. If this does not work you can try jumping directly from the battery terminal on the starter to the output terminal on the solenoid, effectively bypassing the solenoid. If this works you likely have a bad solenoid.

[hellosailor]

Joe-
No offense meant, but the question is akin to asking "Honey, why are we out of milk again?" As you can see from the responses, there are SO many other factors that have to be looked at. What Arthur Conan Doyle referred to as the 'relentless application of logic'.
I think you can bet on a starter problem, because you say the voltage only drops to 12.4 when you turn the key, presumably to engage the starter. If a starter is getting full battery power it will pull the system down to around 10 volts. That is not happening, so it suggests the wiring and connections to the starter/solenoid are corroded or loose, and the starter is not getting power. Typically there's something like a 10g wire to the solenoid, but the starter motor itself is cabled directly to the batteries with a proper heavy cable, which the solenoid relay engages.

I'm an AGM fan, mainly because acid always finds a way to eat something I valued. But I think throwing money into AGMs would be a waste right now. If you can order one of the excellent books by Charlie Wing or Ed Sherman on boat systems, or the "12 volt doctor" "12 volt bible" books (the latter two being older, smaller, not as comprehensive but less reading) they'll show you step by step how to first, confirm that your starter wiring and starter are OK or not. Once you see how simple it is to do that (and it is the same on cars or boats) you will be able to save yourself a lot of grief over many years.

Similarly, the two bigger books will cover the charging system and specifics of how to verify that's working correctly. There are unfortunately no short cuts, but the good news is that it really is NOT complicated, if you have good instructions. And I favor BOOKS over the internet for that, because the books tend to lay it out step-by-step without little omissions. Heck, a lot of libraries have those books available, or can get them on loan from other libraries, for free.

Eliminate the starter issues first, because they're the simplest. And from the 12.4 volts, perhaps the most likely. And those books, really, are not hard reading. Especially if you're stuck someplace less convenient than your home dock.

[sailah]

I have 2 group 31 house, and 1 group 31 start. 2 are AGM, 1 is a diehard deep cycle platinum.

I'm on a mooring in MA with no charging other than alternator. In winter I have my boat plugged into 120 outlet which keeps batteries charged.

5 years still top shape. I think it's you. 12.4v should spin a starter easy. I'd be checking grounds