AGM Batteries

[Seevee]

Charles,

Great to hear from a very experience boater........

Question: Why do you use a portable generator?
And, assume you have no 220v appliances on board, all 120 or 12?
----
My set up is similar, but a bit smaller:
I have 4 (6v) Lifeline GPL-4CT batteries in the house bank (220 amps total usable without going less that 50% charge)
I have a single Lifeline Starting GPL3100T battery

For single engine charging I have an 80a alternator, with a Balmar MC-614H - High Performance External Alternator Regulator, giving 3 stage charging.
For the shore or generator, I have a Magnum Energy MS2812 which also is 3 stage charging and inverter.

All work GREAT! I'm totally sold on AGM batteries, especially the Lifeline (Concord). I've used them in my plane for years with superb results, and their customer service is second to none.

For "me" that's enough power to anchor up mid day, micro a short dinner, a bit of TV, computer that evening, and coffee in the morning before starting the genny or engine. Hard to go 2 full days on anchor, but that's fine for us.

Often for several nites on the hook, we'll crank the genny for dinner, and grill or use the stove as it provides power and charges the batteries.

Now, question:
Considering solar, what would I want to look at to give us enough to provide additional ~220a per day?

(PS Charles, you'll LOVE Georgian and the N Channel for anchoring!)

You asked for experiences with AGM batteries. As had been said, in a nutshell, what I got/get may not be what you get.

Regardless, AGM BATTERIES are only part of the equation. In and of themselves.

As may have been mentioned, AGM batteries have a different CHARGING characteristic than wet cell (FLA). Do you have a charger that handles different charging characteristics?

Along with that do you have a charger that provides a 3phase charging pattern, Bulk, Absorb & Float?

What do you have that will charge the house bank AGM? Are you still going to have FLA batteries for the engine?

My experiences; In '16 I had a house bank installed of 6 L16 6V AGM batteries. Each battery has about 400Ah and they were wired in series & parallel. When this was being done I had 2 4D FLA engine batteries. My charging profile setup in my Xantrex SW3012 charger/inverter was set to AGM, which I knew was not the best for the FLA batteries. Do you have an inverter?

The pervious OEM alternators on the Ford Lehman engines was 60A ea (we have twin engines) which were not the best for charging the banks I had installed, soooo, in went 2 new Balmar 120A/ea alternators. Also installed were 2 Balmar regulators, then 2 Duo-chargers and a centerfielder. The centerfielder decides where to send the charge, house or engine bank.

So, for underway we charge with 1 capability and at the dock, charge with another.

The Xantrex has a control panel so we can see at a glance that status of our house bank. I'm adding a Balmar control panel to keep an eye on the engine batteries that have been changed to 2 4D AGM batteries.

We are on the Loop and last winter we were on the hard on 1 of the Finger Lakes. There on the hard I had no power into the boat and everything shut down in the boat. The AGM stayed around 6V all winter. The FLA had to be charged 4 times. That is why I went to AGM this past spring for engine batteries.

The boat is now in Canada on the hard and I will be going for a visit mid-January to check the batteries. I'm anticipating, based on my experience with the L16's in the Finger Lakes region, that everything will be fine.

We are conservative in our power usage. We can pull into an anchorage, on a wall or mooring early afternoon. Go that day, the next whole day and the next and if we are going to stay longer I will break out our portable generator sometime in the morning and run it for several hours to charge the batteries back up. If we aren't staying the engine batteries have just been sitting waiting so we'll start our engines and move along. A normal day run for us will charge the house bank completely. Currently we have a 2500W charger, but I'm upgrading to a 3500W for '19.

I'm also installing solar panels for '19 as well, hoping to keep up with our usage. IF all goes well, I may install a fuel cell in '20.

We like to anchor and will be doing more as we transition Georgian Bay & the North Channel this coming season. I'm told 1 of the nicest area for anchoring.

BTW, when I was having all of the electrical work done I also installed an ELCI and a Galvanic Isolator. The ELCI helps with different dock power supplies.

Hopefully this shows that AGM batteries are not just AGM batteries. There are a lot of extraneous items necessary to charge and maintain properly the expenditure for AGM batteries.

So far, but mid-January will tell, they are meeting my expectations.

Any questions, email me.

Best regards,
Charles
Charles Williamson
m/v Nepidae
Albin 43 Sundeck
Nepidae.trawler@gmail.com
MTOA 3927
AGLCA 12114

Please keep in mind that emails show no emotion, often omit words, and may be perceived as the opposite of what is intended. A simple phone call is the fastest way to straighten out any misunderstanding or questions.

 

[DFlucker]

AGM or Golf Cart Batterys

I have had my 8 golf cart batteries going for over 12 years on my Morgan trawler. I check the fluid levels ad top up as needed every month. The charging system is supplied by a multi step 3000 Zantrex inverter charger. I checked them last spring they were showing power level like new. They were only cheep Mexican made. I will check them again in the spring and keep my fingers crossed.

 

[MurrayM]

I have had my 8 golf cart batteries going for over 12 years on my Morgan trawler. I check the fluid levels ad top up as needed every month. The charging system is supplied by a multi step 3000 Zantrex inverter charger. I checked them last spring they were showing power level like new. They were only cheep Mexican made. I will check them again in the spring and keep my fingers crossed.

Welcome aboard from up-coast a bit

 

[BrianSmith]

I thought I understood a good bit about batteries and charging, but I don't recall ever seeing a reference to "0.3C", "0.5C", etc. What's the "C"?

 

[RCook]

Refers to the AH capacity of your battery bank. So if your bank was 1000AH, charging at .3C would mean charging at 300 A.

 

[Insequent]

C Rate Explained | All About Lead Acid Batteries

 

[HopCar]

I thought I understood a good bit about batteries and charging, but I don't recall ever seeing a reference to "0.3C", "0.5C", etc. What's the "C"?

Brian, thanks for asking. I had never heard the term either but was too embarrassed to ask.

 

[Delfin]

Refers to the AH capacity of your battery bank. So if your bank was 1000AH, charging at .3C would mean charging at 300 A.

While the "C" value reflects the amount of current you are throwing at a battery from your charging equipment, the battery being charged "CAR", or charge acceptance rate over the full range of the charging cycle, has a big impact on longevity. AGMs are touted as having a higher CAR than traditional LA batteries, which they do. For a portion of the charging cycle, but not that much different over the entire cycle, or at least that is my experience. Since a chronically undercharged AGM or LA battery will have a short life, and since many people don't want to run a genset for hours to complete the charging cycle, or lack sufficient solar or wind to keep them topped up, it is understandable why other chemistries for boats have increasing appeal.

Carbon enriched anode batteries like the Firefly are appealing because they don't die if you undercharge them, but have pretty much the same CAR as other batteries, so if you do want to fully charge them, the last 20% of the cycle will take longer than the first 80%.

Lithium Phosphate has pretty much a flat, and very high CAR, so from beginning to end whatever your C capacity is, LiFePO4 batteries will suck it up (within reason). And, like carbon anode batteries, undercharging them (the dreaded PSoC or partial state of charge) doesn't hurt them.

Some people figure it is easier to just use wet cell LA batteries as you find convenient, then change them when if/they die young.

Which approach one takes is a matter of how much you are willing to pay for certain benefits.

 

[BrianSmith]

Thanks for that good info, people. Sounds like if I have a smart charger (I do), and I have it set to the correct battery type (I do), then the "C" isn't something I really need to worry about. Whew! I really didn't want yet another thing to have to worry about!

 

[firehoser75]

Hi Brian,
According to a very well respected and knowledgeable source on many of the forums (MainSail) who is a marine electrician, boat batteries don't usually die, they are murdered by their owners. He only recommends the extra expense of AGM batteries if they are treated properly, meaning using the correct charging profiles and equally important recharging them FULLY to 100% very regularly. As Delfin has stated, the dreaded partial state of charge will fairly quickly kill (compared to proper treatment) even expensive AGM's, so if that is the way you normally operate (cruise) your boat, then maybe lead acid is a less expensive way to go in the long run. Now AGM have some other advantages (eg. less maintenance, less likely to leak, etc.) so maybe that is important to you and cost is secondary.

Without solar charging, wind charging, or regularly (every few days going to shore power) a boater at anchor either running the gen set or engine for charging is not getting a full recharge, as you would have to run a very long time as the "top up" or last bit to make it to 100% takes a long time.
MainSail has written many great articles on this and many other good subjects, so check out his material. I think his website is PBase.com and you can search his many posts on sailnet or sailboatowners or cruisersforum. Like some members here, very informative!
Merry Christmas,
Tom

 

[RCook]

Hi Tom,

CMS's excellent website used to be on pbase (IIRC), but now he has his own at http://marinehowto.com

 

[SeaMoose]

The AGM's in my truck stay outside all winter, w temps to 10 below F. Those in my 26-foot trailer boat as well. If they are well charged, no problem.

Thanks very much. Must have been a bad battery.

 

[twistedtree]

Hi Brian,
According to a very well respected and knowledgeable source on many of the forums (MainSail) who is a marine electrician, boat batteries don't usually die, they are murdered by their owners. He only recommends the extra expense of AGM batteries if they are treated properly, meaning using the correct charging profiles and equally important recharging them FULLY to 100% very regularly. As Delfin has stated, the dreaded partial state of charge will fairly quickly kill (compared to proper treatment) even expensive AGM's, so if that is the way you normally operate (cruise) your boat, then maybe lead acid is a less expensive way to go in the long run. Now AGM have some other advantages (eg. less maintenance, less likely to leak, etc.) so maybe that is important to you and cost is secondary.

Without solar charging, wind charging, or regularly (every few days going to shore power) a boater at anchor either running the gen set or engine for charging is not getting a full recharge, as you would have to run a very long time as the "top up" or last bit to make it to 100% takes a long time.
MainSail has written many great articles on this and many other good subjects, so check out his material. I think his website is PBase.com and you can search his many posts on sailnet or sailboatowners or cruisersforum. Like some members here, very informative!
Merry Christmas,
Tom

This is all very true, but I think a lot less of an issue/risk on power boats vs sail boats. On a power boat, if you are underway for 4-5 hrs, that will get you charged back up too, and be just like plugging into shore power. The same is true for a sail boat while motoring, however they tend to have smaller alternators so need more time to charge. And of course if you are actually sailing, you are not charging and instead using power and making the problem worse.


The key is to be sure to get the batteries fully recharged every few days. How you accomplish that will depend on how your boat is set up, and your cruising pattern.

 

[Donna]

I just replaced mine the end of November. I had AGM batteries and replaced them with the same lifeline AGM. Yes expensive but for me totally worth it no to have to maintenance them. Unfortunately I can’t lift them. Batteries bought online, delivered on a pallet to the marina, $1,800.00. $90.00 install fee. Super happy I have new ones? Priceless!

There is already so much maintenance on the boat for me, it’s nice not to worry about the batteries.

I have only had the boat for 3 years. She sat for 18 months before I purchased her. There was no date in the old AGM batteries so I am assuming 5 years is prettty accurate from what I researched.

 

[firehoser75]

"The key is to be sure to get the batteries fully recharged every few days. How you accomplish that will depend on how your boat is set up, and your cruising pattern."


TT is totally correct in the above statement. However, the battery acceptance rate (which decreases as the battery charge increases) is the true limiting factor, not the size of the alternator, charger, etc. (Except of course the bulk stage where a larger charge source will allow faster recharging but only to about 85% of a full charge). The last 10-15% of the charge takes a long time, and for a lot of boaters, they do not achieve the required (for optimum battery life) full charge (very often). A good battery monitor is required to really know what is going on with your batteries (charge percentage). For example, I have a 100 amp alternator (car style - stock with the engine) with an internal regulator. It does a very poor job of charging my house bank, but keeps my start and windlass (bow thruster) batteries right up! I have solar, and that charges my house bank to 100% (on most days).
Don't get me wrong, AGM (especially Lifelines) are great batteries, I am just saying that you may be spending a lot of money to avoid checking the water (acid) level.

 

[greatpapabear]

A question that doesn't seem to have been adressed, is whether to leave your battery charger on when connected to Shore Power and absent from the boat.

i've always done this for two key reasons. To ensure the batts are all fully charged; and in case the bilge pumps start and need continuous power.

Your collective thoughts?

 

[Comodave]

We have 2 Promarimer chargers that are multistage so we leave the boat plugged in whenever it is at the dock, which is most of the time. The chargers come up to full charge and then shut off. If we use some lights, for instance, after a while the chargers will come on for a while and then go back off.

 

[Maerin]

My 12V system has evolved over 10 yrs of cruising. I murdered an expensive 1200AH bank of (6) Lifeline L16-2V batteries with chronic PSOC charging. We spend considerable time on the hook. Several changes were key in correcting the PSOC charge issue.

• Changing to a high output (250A) alternator and tweaking the Balmar regulator eliminated any charge issue while underway. My bank now goes to 100% on a typical full day cruise. Perfect for our cruising style since we typically move every few days.
• Added 480W of solar, easily the most beneficial modification! Now, I can run the genset for about 2 hrs in the AM to bring the SOC to about 90%, and the solar will bring the bank to 100% SOC during the day. (the sun must shine!) I also retained my old Freedom 30 as charger only, so with the Magnum 2812, my absorb rate goes to nearly 250A. It works out well for our routine since we can charge to 90% SOC, do a load of wash, make water to offset the wash and supplement, cycle the water heater, make ice, and run our power intensive loads while running the genset. Also loads the genset nicely. By late afternoon, the bank is 100%. Battery capacity is significantly improved since the cumulative loss of capacity with PSOC charging is eliminated.
• We typically shut down the inverter to reduce standby overhead. It's not insignificant. I've also implemented 12V devices in place of wall warts where practical- e.g. USB devices. Not a lot, but makes it more convenient to get the inverter off line for longer periods.

I'm in full agreement that most battery banks are murdered.

 

[Codger2]

...... whether to leave your battery charger on when connected to Shore Power and absent from the boat.

I've always done this for two key reasons. To ensure the batts are all fully charged; and in case the bilge pumps start and need continuous power.

I've been doing it this way since 1995 and have had no problems.

 

[DDW]

We typically shut down the inverter to reduce standby overhead. It's not insignificant. I've also implemented 12V devices in place of wall warts where practical- e.g. USB devices. Not a lot, but makes it more convenient to get the inverter off line for longer periods.

This is often overlooked. If shopping for a new inverter, find one with low idle power. Magnum and Xantrex products are very poor in this regard, many of them drawing as much as 4 amps doing nothing at all. The Dutch products (Victron and Mastervolt) are much better.