Battery options

[mikeracca]

So what I’m gathering from all of you, is the problems with unbalancing batteries is not as much or any issue today. I would imagine higher quality controls and better building techniques would alleviate this as an issue, or at least make it rare. Ok got it 2 GC2 batteries are going to serve me well….

As for how can there be a difference between 1x6 cells and 2x3 cells. Simple… it goes back to quality control and variations between batches. I said it already there can be differences in batteries built at the same month if they are from different batches. A single battery will be built in the same batch and have the exact same chemistry through each cell. If all batteries were always built exactly the same and all batteries were built perfectly then there would be no need for a warranty because every battery would be perfect. We all know this to not be true. I sold auto parts for 15 years and while not as common in modern batteries as it was in batteries when I first started you do get bad ones from time to time.

 

[leo310]

I have only used 6Volt GC batteries over the last 20 years. They are the Interstate fld GC 225 amp 6v, total used is 4 to give 450 amp hr/ 175 usable amp/hr. The main thing that you need to do is make sure that the connecting cables (battery) are all the same length the only one that can be different are the take off to the main bus's. The Pos to the bus bar is from 1 battery the Neg is from a different battery. Charging is done with 1 12 volt charger during the winter and summer its done with solar panels (350 watts), so far in the last 4 years the lowest discharge I've done is 35% of capacity (1 week no sun on anchor).

 

[jssailem]

I bought my first pair of batteries in 2015. I upgraded the charger to a Sterling PCU 40Amp at the same time. Then in 2020, I bought a 3rd batter to be my start battery and upgraded my Alternator. I will be adding Solar in the next year or so to enhance my stay at anchor time.

 

[Stu Jackson]

So what I’m gathering from all of you, is the problems with unbalancing batteries is not as much or any issue today. I would imagine higher quality controls and better building techniques would alleviate this as an issue, or at least make it rare. Ok got it 2 GC2 batteries are going to serve me well….

Thx, Mike.

 

[BigEasy]

So what I’m gathering from all of you, is the problems with unbalancing batteries is not as much or any issue today. Ok got it 2 GC2 batteries are going to serve me well….

But you might want to consider using your two 6 volt GC batteries for the house bank and installing a separate Gp 29, 12 volt battery for a dedicated starter bank wired into your battery switch ...just in case one of the 6 volts fail or the batteries become depleted.

 

[mikeracca]

So I’m looking at a replacement battery charger as my boat still has the flyback fire starter onboard. The model I want isn’t available any more, it has been replaced by a new version. Thank you @Stu Jackson for the rabbit hole I have went down researching battery chargers. Before I pull the trigger on one I wanted your guys‘ opinions on my selections.

ProMariner

https://www.amazon.com/ProMariner-44012-ProSportHD-Battery-Charger/dp/B081VVKCH6/ref=pd_vtp_5/134-4057389-0125644?pd_rd_w=V6GlV&pf_rd_p=016e3697-91be-4dc2-9533-ef9350e7e73d&pf_rd_r=Q32NJXYTGMZKT5NY2J0D&pd_rd_r=c576c9ef-e8fe-4d1d-a120-e6fd81453f41&pd_rd_wg=36eYR&pd_rd_i=B08FY8LTDP&th=1

Noco (I really wanted the Noco Genius G4, 4 bank charger but I can’t find it anywhere)

https://www.amazon.com/NOCO-GENPRO10X3-Fully-Automatic-Temperature-Compensation/dp/B08G3DLYX8/ref=pd_lutyp_ci_mcx_mr_typ_d_1/134-4057389-0125644?pd_rd_w=VDjUt&pf_rd_p=f6afbe6e-f56a-4b64-9493-07a01722d421&pf_rd_r=G51S25ZVXTWSRVQEGZTD&pd_rd_r=032d09d1-1c16-4dec-a8f5-cd97cbd2d5ad&pd_rd_wg=DhDUu&pd_rd_i=B08G3DLYX8&psc=1

NOCO was the brand of the balance charger that I used to have that found a new home with a “friend”, so I am very well familiar in the quality of their products.

These 2 chargers are well in my budget and I feel from my time in the rabbit hole will serve my needs perfectly. Features I wish each one had was remote indications so I could see a readout of battery status from the charger but at my chart table or another convenient location. The chargers that do offer this are about 2x the money and really only offer that one extra feature over these. So I’m not sure that’s much of a value, especially since I still have to spend another $60+ on the indicator panel.

 

[jssailem]

Here is the 20amp version of the Sterling. Reasonable price. Has the ability to set your own profile to match the batteries you get.

Sterling ProCharge Ultra Battery Charger

Sterling Power ProCharge Ultra World-Voltage Battery Chargers: Award-winning design and performance! Select your model above.

baymarinesupply.com

 

[DayDreamer41]

Yea, I think these are the old almost square 4D group batteries. I couldn’t get a good look at the label. I just recognized them as 6v with only 3 fluid caps. They look almost exactly like these.

View attachment 202833

After much research I replaced my 4D batteries on our ship with the Trojan T105's, they are the best bang for the buck, true deep cycle batteries, there are no better FLA batteries for a sailboat than these.

 

[jeepbluetj]

You don't need a triple charger if I understand/remember what you're planning for battery banks. You may wish to have a dual or just a single.

From upthread, I assume you'll stuff 2 6V GC2 batteries under the chart table as a house bank, and may want a starting bank elsewhere. So you can save a few pennies and go with a two bank charger. There are other options with an ACR if you're interested in going that direction.

I solved the exact same problem with a 1 bank charger for the house + a very small battery tender for the start. The start never really gets drained unless you leave the switch on "both" which nobody should do

 

[Stu Jackson]

Wiring a new charger From Maine Sail:

Marine Battery Chargers - Installation Tips & Considerations
and
Installing a Marine Battery Charger - Marine How To

IMPORTANT Advice on these charger settings: Electrical Systems 101

and

Making Sense of Automatic Charging Relays (2019)
Making Sense of Automatic Charging Relays - Marine How To

 

[Benny17441]

Hey, we all have our preferences. I like batteries that will last long when used and maintained well, but that are not that expensive that I would not dare to abuse them when needed. I also like readily available batteries that wherever I can get off the boat I could easily find a replacement. I like fresh batteries and not ones that may have been sitting on the shelf for months and I like batteries with good warranties that are honored at any national retailers.

 

[mikeracca]

I was planning on using a 3 bank charger in the case that I expand in the future. I find spending an extra $60 now to get a 3 bank charger will save me $300 in the future if I decide to add a bank under my settee.

Here is the 20amp version of the Sterling. Reasonable price. Has the ability to set your own profile to match the batteries you get.

Sterling ProCharge Ultra Battery Charger

Sterling Power ProCharge Ultra World-Voltage Battery Chargers: Award-winning design and performance! Select your model above.

baymarinesupply.com

This is actually the charger I really wanted… well the ProNautic version, but even in its cheapest form it was still more expensive than the others that were in my budget. Here is well within what my wallet can take and it’s the model I’m looking for! Thank you again. Looks like the first round is going to be on me when we get to meet up, you have been a great help!

 

[Stu Jackson]

I was planning on using a 3 bank charger in the case that I expand in the future.

Mike, what 3 banks would you conceivably think you'd install?

 

[Maine Sail]

The balance issue is real but extremely rare if the batteries are properly commissioned. Thes is as easy as it gets. Wire them in paralleland charge at the rec absorption voltageand let the accepted current decline to below0.5% before putting them series. Done. We do this for every series wired battery we install..6V GC2 batteries are a far better solution than any flooded 12V battery you will find unless you spring big money for Rolls.The next best solution would be the Trojan SCS series but these are not even half the battery a T105 is...
if you have a Victron battery monitor it can be set up for mid point monitoring..The money yousave using GC2's will pay for the battery monitor..

 

[mikeracca]

Mike, what 3 banks would you conceivably think you'd install?

Right now I have starting and house. If I built a 3rd bank I would either tie it into the house for longer duration, and or have the 3rd bank on an inverter. That is the general thought at the moment. Further advise or research may change this In the future.

 

[Stu Jackson]

tie it into the house for longer duration, and or have the 3rd bank on an inverter.

House -- then you don't need a separate bank
Inverter -- worst thin g to do is a separate bank because inverters need big backup. The bigger the bank for an inverter the less the voltage sag. That's thing the thing to learn about.

House -- again... then there's this Basic 101:

IS IT BETTER TO HAVE ONE OR TWO BATTERY BANKS FOR HOUSE USE?
(By Nigel Calder - I DIDN’T write this!!!)



This appears in Calder’s excellent Boatowners Manual. I bought the 2nd edition in 1998.

The [formerly – pre-1990s] popular arrangement of having two house banks alternated in use needs scrutiny before I go any further.

LIFE CYCLES: As we have seen, the life expectancy of a battery in cycling service is directly related to the depth to which it is discharged at each cycle - the greater the depth of discharge, the shorter the battery’s life.

This relationship between depth of discharge and battery life is NOT linear. As the depth of discharge increases, a battery’s life expectancy is disproportionately shortened. A given battery may cycle through 10% of its capacity 2,000 times, 50% of its capacity 300 times and 100% of its capacity around 100 times.

Let’s say, for arguments sake, that a boat has two 200-ah battery banks, alternated from day to day, with a daily load of 80 Ah. Each bank will be discharged by 40% (80 Ah of one of the two 200 Ah banks) of its capacity before being recharged. The batteries will fail after 380 cycles, which is 760 days (since each is used every other day). If the two banks had been wired in parallel, to make a single 400 Ah battery bank, this bank would have been discharged by 20% of capacity every day, with a life expectancy of 800 days, a 5% increase in life expectancy using exactly the same batteries!

But now let’s double the capacity of the batteries, so that the boat has either two 400 Ah banks, or a single 800 Ah bank, but with the same 80 Ah daily load. The two separate banks will be cycling through 20% of capacity every other day, resulting in a total life expectancy of 1,600 days. Doubling the size of the battery banks in relation to the load has produced a 210% increase in life expectancy. The single 800 Ah bank will be cycling through 10% of capacity every day, resulting in a life expectancy of 2,000 days - a 25% increase in life expectancy over the two (400 Ah) banks, and a 250% increase in life expectancy over the single 400 Ah battery bank!

There are two immediate conclusions to be drawn from these figures:

1. For a given total battery capacity, wiring the (house) batteries into a single high capacity bank, rather than having them divided into two alternating banks, will result in a longer overall life expectancy for the batteries.

2. All other things being equal, any increase in the overall capacity of a battery bank will produce a disproportionate increase in its life expectancy (through reducing the depth of discharge at each cycle).

FOR BATTERY LONGEVITY, A SINGLE LARGE (HOUSE) BANK, THE LARGER THE BETTER, IS PREFERABLE TO DIVIDED (HOUSE) BANKS.

 

[SycloneDriver]

I've been working with flooded batteries almost ever day for the last 12 years. 24 cells wires in series and generally 2 to 5 strings wired in parallel. They support communications equipment 24/7/365. They float at 52.80 volts, unless they are discharging. I rarely have an imbalance issue. The batteries generally last 25 years. The batteries that do fail are most often cracked cases or leaking post seals, I do occasionally see shorted cells. The shorted cells generally float at 2.0x volts and a normal cell floats at 2.20. Oddly a low cell preforms just fine during a discharge test, but they are generally replaced quickly after discovery. I have one string of 24 cells that are paralleled with 4 other strings, it is now almost 40 years old!

Edit: I have applied a single cell charger to the low/shorted cells. The charger was set to 2.55 volts and limited to 10 amps. The charger was allowed to run for a minimum of 4 days. The following day the low cells would settle back to 2.0x volts. It almost never resulted in cell recovery.

I don't have imbalance issues on my boat, RV, or on my solar project (10 x 12v batteries @ 24v).