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Best AGM battery


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1 hour ago, wheels said:

Good catch mcp. You are correct. As usual, these subjects are always more complicated than simple explanations.
The Epever has a user defined set up. So I am pretty sure it can be configured to suit. In saying that, it may well be more complicated and involved than Sabre wishes to get.
However, as said just above in Aleana's post, AGM's are not all created equal either. The specs are extremely important to understand and the charger needs to be set up just right, or the batteries will die in a very short time.

Sabre, it is probably well worth buying from someone that can install and also set up the charger for you.

Sooo, what were you charging before. The LC batteries should accept a much higher Charge Current than any FLA of same Ahr capacity.
You do not have to charge at the full charging current. If you are currently charging FLA with say 50A, then the LC batteries will charge just fine. (not factoring the voltage as in the above discussion)It is just that they are capable of taking much more. If we look at the Narada, they are only 6V Batteries, so you need 2 to get 12V. Thus they are capable of handling 140A being fed into them.

I didn't consider Firefly as I don't know of a NZ supplier.

Sorry Sabre no hijack here as carbon are essentially AGM but carbon variety and as Wheels said a serious contender if they be charged at 0.5C, and you have the means. Also tolerant of Psoc and have a longer plateau at beginning of absorb.

Wheels I thought the same but when I called Peter 6 months ago he said to maintain warranty I would have to restrict the 12v series bank to 75A.

So I immediately discounted them as a possible as my bulk charge is 110A.

I just left a msg to clarify as I’m keen again owing to FF’S being off the cost effective list.

Difficult to separate fact from fiction, as usual.

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My experience last 12 months tells me that is a recipe for disaster.... I had 4x big expensive AGMs fitted to my boat last year by a well known professional marine electrics company and they made

What type of boat are you building?   Money no object,  no question, Lithium titanate for any purpose.   Otherwise for a cruiser/liveaboard Lithium Iron Phosphate or Lead carbon from a reput

1 hour ago, waikiore said:

I believe that you are one of many Aleana, a year ago I did a lot of research on AGM batteries as I needed a good reliable start battery for a classic car that did not have room for a properly sized FLA. I discovered that one Auckland marine sparky crowd had been supplying sets of AGM batteries (of good quality) to a number of craft but not checking on the boats charging regime. For these batteries to last and give the paid for life -your charger has to be capable of charging at a rate of over 24% of the batteries A/H rating -when required in the bulk phase. To ignore this  little fact is to accept very much shortened life and battery performance.  Only this week I discovered another boat set up this way.

Yes I agree, I suspect there are lots of boats out there with a mismatch between the battery’s ideal profile and the charging system’s actual profile. And some of those have been setup up by so-called experts.

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From horses mouth, 50A continuous and 75max short duration 2x6v in series.

Regarding Narmada carbon 6v 300Ahr. At 6v,  6.9v Max voltage the internal resistance + battery emf will not allow more than 75A as long as it’s not below 90%  Depth of discharge.

At 12v and double above “resistance” same scenario.

If you up the voltage to more than 13.8 you will get more current and gassing and your AGM will be toast.
Ive been thru this before as not what I want. Sabre if you can adjust your voltage they may be just up your alley.

Dont know about longevity. Bit of punt as I know none with them.

FireFlys are different in as much they will take o.5c iircly. Cutting edge carbon.

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Great info.. thank you all. It will take me awhile to process it all.

I was quietly hoping the choice would be made super simple for me but alas....... 

One thing that has been made clear is that even the "experts" get the set up wrong so I need to figure it out and install it myself.

Wheels, my current set up is a 110a/h FLA house plus a seperate start battery. It is charged by 150w solar through the Epever. I also have the standard alternator charging through a BEP dual battery charging cluster.

I set all this up when I bought the boat and it has served me well but this summer I added a fridge which has seen my battery struggling a bit in the evening and I feel its performance is dropping.

I also like the idea of getting away from an FLA to eliminate the gassing issue.

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OK Sabre, here are my suggestions. Get a PDS for your existing battery. Ensure that the EPever is set to exactly those volts, for both bulk and float, measured AT THE BATTERY. Not out by 0.1v, exactly right. EPever units are not that bright, and will only do bulk for a set time, not by volts or current. Some have a constant, non configurable gap between bulk volts and float, especially if yours is one of those, you may want to consider a better one.

Even if you upgrade the battery, you will have to do a matching alternator/ regulator setup, so step 2 would be a decent external regulator for the alternator, with alternator temp sensing and batt temp sensing, AND compatible with Lithium ability in case you want to go there. Then have the existing alt modified (not expensive) to use the new regulator, and set it for the right parameters for all three charge stages, bulk, absorb and float. 

Third would be to see if that is sufficient - it will reduce your charging times on alternator by 30% or more over a fixed voltage regulator.

If that is not sufficient, THEN look at the newer battery technology, which will be much more "drop in" than for your existing  system. Alternator could also be replaced with a larger unit if required. Also more solar???

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Thanks IT.. the PDS is in the boat so I will have a look at that. Is the DVSR on the BEP switch not up to the task?

I'm trying to avoid relying on the alternator for any house battery requirements so I don't need to run the motor for anything other than motoring.

I have fairly modest electricity needs so I think I would be there with just a bit more storage for night time. My battery doesn't take long to top back up the next day...

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Mine very same as Sabre's(120a. AGM, 160w solar) And just fired up new install of sm frig. All coping OK so far.Trouble tho, with adjusting epever Tracer AN1210. Wont download to ph(my only device) or do I need to buy an accessary to do that?

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9 hours ago, Sabre said:

Thanks IT.. the PDS is in the boat so I will have a look at that. Is the DVSR on the BEP switch not up to the task?

I'm trying to avoid relying on the alternator for any house battery requirements so I don't need to run the motor for anything other than motoring.

I have fairly modest electricity needs so I think I would be there with just a bit more storage for night time. My battery doesn't take long to top back up the next day...

Actually, it takes up to 10 hours to get an agm back to 100 percent. Regardless of your charging system, it’s in their nature! (well, chemistry). So if you think you have done it in an hour or two you are mistaken. It’s fully charged when it’s at the absorption voltage, and the tail current is about 1 percent of capacity. If you can’t measure that, you don’t know how charged it is.

So “all I added was a little fridge”. How much does it draw? Does it cycle or run all the time? So then, from amps draw and time on, you can work out amp hours. Once you know that, add 10% for charging losses. Now, with lead acid, most boats don’t get back to over 80-90% of charge every day, and lead acid should not be discharged over 50%, so you have 30-40% of useful capacity. 
 

Say your useable batt is 40 a/hrs. Fridge draws 4 amps. You can run it 10 hours. Then you must recharge. But don’t forget other loads, like lights, stereo, anything else in your calculations.

Now, the best way is to use a decent alternator while the battery is accepting lots of current (amps). So that’s first thing in the morning. Once the battery is accepting only about 5% of capacity, the solar can finish it off.

To have this data, you NEED a battery monitor, volts won’t do.

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43 minutes ago, vic008 said:

Mine very same as Sabre's(120a. AGM, 160w solar) And just fired up new install of sm frig. All coping OK so far.Trouble tho, with adjusting epever Tracer AN1210. Wont download to ph(my only device) or do I need to buy an accessary to do that?

You have to have one of the accessories, wifi or Bluetooth. Ebox-wifi-01 or Ebox-BLE-01. There is also a wired solution, but I’ve never seen one...

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