So, what battery if you live largely on the hook?

[Franziska]

Hi to the electric specialists out here.

I read the recent thread on Firefly AGM batteries and have the impression that they are perfect for those frequently pulling into marinas and beeing able to give a 100% topup charge.

That does not line up with my kind of cruising, which happens nearly 100% on the hook.

As my current two 90Ah gel house batteries, which came with the boat, will need replacing I wonder what will be the best cost effective(!) option.

For charging I have:

*Solar panels delivering constantly 13.3-13.7Volt with 3-4Amps (they are a bit old &#128117 on a average sunny day.

*Genset which I run every 3-4 days for one hour.
It charges then via the 220V output and a Waeco Perfect Charge 1235 charger. Typical current I see when charging is 14.4V - 14.8V.
I really hate to run the Genset, but can tolerate an hour or so.

*Two Yamaha 9.9 starting and running as well as charging exclusively a separate starter battery.

*Wind gen, to be added soon. I anticipate 3-5Amp constantly from this if there is constant wind.

Most demanding power drain situation is probably sailing at night with Electronics and electrics running:
1xLaptop via 12v DC to 19v DC converter, 1x AIS/GPS, 1xNavtex, 1xVHF, 1xFishfinder/Depth, 1x ST 5000+ Autopilot on tiller, 360 degree Led Tricolor, 3-4x LED interior lights, 1xphone charging.

No radar (yet!), but might be added soon.
So I'll add another 90Ah battery to the housebank (=3x90Ah total).

It can happen that the batteries go down to 11.5V in these circumstances.
I can top them up with the genset but only at a rate if 1hour at a time.

Currently I have no fridge running, but there is a household fridge which could be connected via an DCAC inverter.
Guess I need an extra battery to run this.

I'm wondering now, what's the best deep cycle battery which likes beeing permanently topped up rather than needing those long 100% charges which AGM seem to like.

I'm rather after a solid recommendation for the scenario above and not after a electricians specialist discussion I possible.

PS.:If you recommend brands, I'd appreciate anything available in France.

Thanks so much!



Summer 2016 English Channel & beyond - Catamaran Lady Rovers Website!

[zeehag]

most folks out here are using trojan or similar golf cart batteries, lead acid. some use agm 12 v batteries, depending on storage availability inside boat.
solar and wind, plus occasional engine run to top em off if needed.. why go into marina??
until i had my runaway diesel episode i was always at anchor except cane season. now i repair that which i prolly shoulda repaired before leaving usa, but glad i didnt as it is cheaper and better to fix here.
as battery supplies are not the same world wide, make sure what you change to is available wherever you wish to cruise. there are no lithium ion batteries that i have encountered in mexico.
whatever is in costco, sams club and the brand LTH are available in mexico.
research well. you may decide that the newest and fanciest stuff isnt available world wide. have fun with this.
i donot know france, but i presume the similar issues with supply. please let us know when you are satisfied with your source. i only used mexico as an example of lack of supplies common in other locales.

[dlymn]

I haven't had much luck with AGMs and so am now trying flooded cells. I think my problem was an automatic charger that had lost its smarts and cooked the batteries. The new batteries can be topped up whereas you can't do much with sealed batteries. Given these considerations, I reckon any deep cycle will do. Can you fit 140 AH batteries in? I would be looking at having at least 250ah available for all your expected running gear. That's a total of 500ah when you consider 50% discharge.
We get very little joy from our wind generator. The charge controller cuts the charge at 14.4, the gennie brakes and then starts up from scratch. It won't start charging until it gets above battery resting voltage and so more than 70% of the time the gennie provides no power. We feather the gennie when the wind gets above 20 knots; it's running crazy at that speed

[44'cruisingcat]

More up front cost, but Lithiums (LiFEPO4) are well suited to living on the hook. Really deep cycling shortens the life of lead acid considerably. Lead acid batteries like being 100% charged as often as possible.


Lithiums handle deep cycles better. (As long as you don't flatten them completely) They don't need to be kept close to 100% charged, in fact they'll last longer if you don't charge them to 100%.


They do cost more, but not as much as first appearances suggest, because you can get the same results from a smaller bank. And they SHOULD last longer, in terms of cycles.


Winston brand LiFEPO4 seem to be decent value.

[Sailmonkey]

Generic answer? Golf cart 6v batteries wired in series. These are cheap and forgiving.

But you do need to be sure you're feeding them sort of correctly. How big is your battery charger (amps), the use of the term current and stating voltage is meaningless. I ask as the larger your battery bank, the more useless an hour of charging will do with a small charger.


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[Neptune's Gear]

You don't have much capacity. You have shortened the life of your batts by discharging them too much. You should never let them get below around 12.1v, or 50% of capacity.
Volts is not current. Amps are current, and amp hours is capacity. Most cruisers have over 400 amp hour capacity, some over 1000. Batteries require specific charging voltages, and a bit of understanding to look after them and get the best out of them. Sorry, but it is worth getting a bit technical. Nigel Calders book is a good start. Too much to go into here.

Get a battery computer, but ensure it is installed by someone who understands the correct programming, otherwise they can provide poor information.

Here is an example from my own boat.
I have 2x 220ah 12 volt agm gel hybrid batteries. They are in excess of 12 years old, including over 3 years live aboard, mostly on the hook. I use a BEP battery monitor to provide state of charge information. I have wind and solar power, as well as a Balmar alternator with an ample power next step regulator. All the regulators (alt,wind,solar,shore power charger) have been programmed/setup to exactly meet the manufacturers recommended voltages for the three stages of charging, bulk, absorbtion, and float.
My batts have shown only this year, that they are not what they were, and they will soon be replaced.
In all this time they have been discharged below 50% 3 times, by mistake when away from the boat - failed shore power connections with the freezer left on.

Pretty damn good service from these batts I reckon, and I'll be replacing them with similar ones.

Good luck, but do the math for your boat - daily consumption, recharge rates, time etc to be sure you don't both waste your $, and end up in the same place again in a year or two.


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[Franziska]

Thanks so much.

Zee has a good point on Lithium & equipment availability. Lithium would mean a new charger & new solar controlers, no?
Still they might be good, as a charger does not quit often and if they last well there might be no need to replace any time soon.

My charger does 35amp max if I run it of the genset.

What is the advantage of 6v vs 12v?
So far I thought higher current means less losses.

Hmm. Keep the thoughts coming..

Thanks Franziska



http://ladyrover.jimdo.com/photo-log...hannel-beyond/

[Franziska]

Neptune's

Great info. Came in after my reply. Thanks!

[44'cruisingcat]

Volts aren't current. Current is measured in amps.


Lead acid cells are generally 2 volts. A 6 volt battery is 3 cells. A 12 volt 6 cells.


In general terms the bigger the capacity (lots of amp hours) the heavier the battery. Some big capacity batteries are made in 6 volt, really to make them easier to handle. You would wire two six volt batteries in series to make 12 volts.


Probably all the electrical equipment on your boat will be made for 12 volts.

[a64pilot]

If money is an object, you can't get an amp hour cheaper than in a Walmart or SAMs Club, Costco golf cart battery. I assume there is a French supplier?

If money is no object, then you likely can't beat LifePO, but I believe you have to know a lot about what your doing with LifePO.


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[Franziska]

Guess it's golf cart style batteries this time.
Lithium in a few years time.

Will increase the battery bank size. Still, definitely no Aircon or freezer on this boat.
No electric winch or windlass either.

Yes, boat is fully 12Volt system so far.

Btw. Simplfied I understand the difference between Amps=Flowrate, Amp hours=Tankvolume and Current=Pipe diameter.

One more thing are there low maintenance gel type golf cart batteries?

[Sailmonkey]

You don't want gel if you can't properly charge them.

There are, but you'll spend a lot to get them and you'll kill them early.

And current is amps

Colts is pressure.


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[Franziska]

Monkey, the Waeco Perfect Charge 1235 should be smart enough for the Gel Type, no?

I might need two Waeco Perfect Charge 1235 though, because one can only handle two batteries (+a separate starter battery) at a time.

The new bank will most likely be 4x90Ah.

[Sailmonkey]

As stated in this article, the worst enemy of gel is continuous undercharging. If you're only running a generator for an hour a day with a 35 amp charger, and seeing voltages as low as 11.1, you are most certainly habitually undercharging. This isn't an accusation, it's just a simple reality.

That 35 amp charger, in a perfect world on a good day will only replace 35 amp hours of juice. In reality, less when losses are accounted for. I know you've got other sources, but I'd still bet you're maintaining a perpetual state of charge below 90%.

Are your batteries difficult to reach for service that makes you want gel?


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[44'cruisingcat]

Originally Posted by Sailmonkey

Colts is pressure.

Volts.