What size and type batteries do I need for a crossing.

[Pete7]

Sam, were is the boat in the EU?

That might affect what batteries are available.

Pete

[sebathon]

Originally Posted by Pete7

Sam, were is the boat in the EU?



That might affect what batteries are available.



Pete

Hi Pete,

You think Lifepo4 is a bad option? I can’t really afford to upgrade the whole system to suit lithium. Maybe just the charger system to suit AGM.

Boats in Portugal and have been looking for retailers that post to here. SVB does but they have limited options two of which I’m considering I have listed above.

I do have a hydrovane so there is the option to rest the batteries when the conditions suit.

Thanks

[john61ct]

A solid LFP system can be installed by Victron or MasterVolt, but pricey.

I'm sure same applies to their AGM.

Varta dunno, but known good AGM from NA include Odyssey, Northstar and Lifeline, see if they're available.

If not, Full River, maybe Trojan. Other brands specific to EU may be fine, but get advice from a trusted source, a "deep cycling" label does not necessarily make it so for longevity.

The key is how you treat them, not just the brand.

[ramblinrod]

Originally Posted by sam_hawk

Hi,

Just in the process of upgrading electrics onboard a 40’ cruiser for a planned Atlantic crossing this year and not really sure on the total capacity or type needed for this.Currently have 280Ah ( 2x 140) lead acid cells and it’s never really capable of running the AP for anything longer then an hour or so.

My usage is mainly autopilot between 2 and 8 amps depending on weather, fridge usually 7amps and some basic instruments and lights and device charging.

Have installed silentwind 400w and 440w solar which has helped a little but I’m concerned to total Ah storage is not sufficient.

If anyone’s does a similar trip and knows what’s works well or doesn’t, advice would be much appreciated.

First, it is impossible to advise with any degree of certainty without knowing the system and user needs.

I understand you are crossing the Atlantic soon, but then what?

For example, how long will you own the boat? If a solution consideration has a long pay back, it may be a poor investment, if you sell the boat before it is realized. (Remember that average person owns their "this will be my forever boat" for about 6 years, and then they move up, move down, or move out of sailing.

If you plan to daysail from a marina, the answer is way different than if you plan to live-aboard on the hook.

Anyway, as a general rule of thumb without knowing details, the following should be decent...

Battery Technology:

A) If boat is most often on shore power, and batteries are located in ventilated, unoccupied space, choose standard lead acid batteries.

B) If boat is most often on shore power, and batteries are located in non-ventilated, occupied space, choose a sealed battery technology.

C) If boat is most often off-grid, and you are not sure how long you will own it before changing boats, go with a low purchase priced solution, of A or B.

D) If boat is most often off-grid, and you "know" you will own it at least 4 years, go with a premium-priced solution of A or B.

E) If boat is mostly off-grid, and you "know" you will own it for 7 years or more, consider LFP.

F) If money is no object, do whatever you wish.

Capacity:

Again this is best determined by needs and energy analysis of the particular case, but for a typical cruising boat your size, with the loads you have described, living aboard and rarely connected to shore power, I normally recommend...

For every 1 A-hr of anticipated daily consumption (at anchor)...

1. 3 to 4 A-hrs of house bank.
2. 3 to 4 Watts of alternative energy power generation.
3. 0.5 to 1A of alternator capacity.
4. 0.4 to 0.6 A of shore power charger.

Example: 40 ft boat, having a BD-35 compressor on a normally insulated ice box, with typical complement of vessel systems, instruments, and mobile charging needs.

Being reasonably energy conservative, at anchor, you will likely consume about 100 A-hrs/day.

Then I recommend:

1. 300 to 400 A-hrs of battery capacity (technology doesn't really matter).
2. 300 to 400 W of solar. You could choose all solar, if you hate noise and mechanical device maintenance/repair. If you do wish to have a wind generator, ensure at least 50% of the need is met by solar.
3. 50 to 100 A alternator.
4. 40 to 60 A shore power charger.

If you have higher than "typical" daily energy consumption needs, you will need to step up everything in ratio.

If your consumption is so high the battery capacity at this ratio becomes untenable, you will likely need a generator.

[Pete7]

Originally Posted by sam_hawk

Hi Pete,

You think Lifepo4 is a bad option? I can’t really afford to upgrade the whole system to suit lithium. Maybe just the charger system to suit AGM.
Thanks

Yes unless you want a steep learning curve before you install them and then monitor very carefully. If you are to cross the Atlantic in 2 months time you have far more important things to do in preparation than experimenting with LifePO4, never mind as you say the cost.

This article by mainesail (a member on here) is worth 30 minutes study to realise why not:

https://marinehowto.com/lifepo4-batteries-on-boats/

So what to choose?

These are new and claim 2000 cycles, sadly they hit the market this Spring just after I replaced my house bank

https://www.alpha-batteries.co.uk/12...isure-battery/ Just don't know if they will deliver.

The Varta's 210AH are average, not great, not bad with a claimed 800 cycles. However, prices of batteries in the EU are expensive, SVB included.

How about talking to the local Portuguese Trojan dealer:

Resultados | Daisa

I know you said you wanted sealed batteries, but a bank of Trojan T105s will give you 1700 cycles if they fit, also available everywhere. You need to check the battery compartments. However, they are very good bang for buck and very popular for this reason on here with cruising folk. It would be the safe option.

https://www.alpha-batteries.co.uk/t-...cycle-battery/

Final suggestion, Rolls batteries also very well thought of. The local Portugal dealer even quotes prices of all there batteries:

http://www.ffsolar.com/products/FF_lista_PVP.pdf

[john61ct]

Yes FLA is better value, but both Trojan and Rolls also market AGM.

[Flod]

Originally Posted by Pete7

Sam, were is the boat in the EU?



That might affect what batteries are available.



Pete

I think he is in Norway according to an earlier post.

To the OP. Talk to these guys : https://makspower.no

[tarian]

Originally Posted by ramblinrod

First, it is impossible to advise with any degree of certainty without knowing the system and user needs.

I understand you are crossing the Atlantic soon, but then what?

For example, how long will you own the boat? If a solution consideration has a long pay back, it may be a poor investment, if you sell the boat before it is realized. (Remember that average person owns their "this will be my forever boat" for about 6 years, and then they move up, move down, or move out of sailing.

If you plan to daysail from a marina, the answer is way different than if you plan to live-aboard on the hook.

Anyway, as a general rule of thumb without knowing details, the following should be decent...

Battery Technology:

A) If boat is most often on shore power, and batteries are located in ventilated, unoccupied space, choose standard lead acid batteries.

B) If boat is most often on shore power, and batteries are located in non-ventilated, occupied space, choose a sealed battery technology.

C) If boat is most often off-grid, and you are not sure how long you will own it before changing boats, go with a low purchase priced solution, of A or B.

D) If boat is most often off-grid, and you "know" you will own it at least 4 years, go with a premium-priced solution of A or B.

E) If boat is mostly off-grid, and you "know" you will own it for 7 years or more, consider LFP.

F) If money is no object, do whatever you wish.

Capacity:

Again this is best determined by needs and energy analysis of the particular case, but for a typical cruising boat your size, with the loads you have described, living aboard and rarely connected to shore power, I normally recommend...

For every 1 A-hr of anticipated daily consumption (at anchor)...

1. 3 to 4 A-hrs of house bank.
2. 3 to 4 Watts of alternative energy power generation.
3. 0.5 to 1A of alternator capacity.
4. 0.4 to 0.6 A of shore power charger.

Example: 40 ft boat, having a BD-35 compressor on a normally insulated ice box, with typical complement of vessel systems, instruments, and mobile charging needs.

Being reasonably energy conservative, at anchor, you will likely consume about 100 A-hrs/day.

Then I recommend:

1. 300 to 400 A-hrs of battery capacity (technology doesn't really matter).
2. 300 to 400 W of solar. You could choose all solar, if you hate noise and mechanical device maintenance/repair. If you do wish to have a wind generator, ensure at least 50% of the need is met by solar.
3. 50 to 100 A alternator.
4. 40 to 60 A shore power charger.

If you have higher than "typical" daily energy consumption needs, you will need to step up everything in ratio.

If your consumption is so high the battery capacity at this ratio becomes untenable, you will likely need a generator.

This is the best advice on this thread and you should consider it with great detail,
Remeber that, what is the point in 1000 watts of solar and a windvane , when you recharge your battries by 10am and all that energy gets wasted , look at you power comsumption carefully and plan accordingly , on an Atlantic crossing your windvane will take most of the load so your autopilot will not be needed as much , much less power then neeeded

[Pete7]

Originally Posted by Flod

I think he is in Norway according to an earlier post.

To the OP. Talk to these guys : https://makspower.no

The boat is in Portugal according to post no 17.

Pete

[Sailing4Jesus]

If one remembers the Titanic which didn't have enough life rafts, then in my unlearned opinion it is better you have too many Batteries than to get out in the middle of the Atlantic and discover you don't have enough.

Senior Chief, USN, Retired

[ramblinrod]

Everything needs to be balanced. More batteries than needed is bad, when one had insufficient food and water.

Yes, one can have too many batteries, if it is at the compromise of something more essential.

[TrentePieds]

Sam Hawk:

Start with the easy bit first: AFAIK there are really only two BRANDS of batteries available in Norway: Exide and Odyssey. These days when goods from one manufacturer are sold under divers labels, there is no way for me to know who makes each of these brands. The place to go to find out is:

https://www.gylling.no/batterier.php?do=view&id=17

Your boat is in Portugal, you say. I dare say that the supply situation in Portugal is much the same as in Norway. I think you should be able to do your "homework" in Norway and defer the purchase of anything you may need until you get to Portugal.

It sounds to me as if your existing batteries have come to the end of their anticipated service life. Quite apart from that, since I consider batteries "consumables", if I were setting out across the Atlantic I'd just bite the bullet and replace the existing batteries with new ones. Even for longish cruises I see no need for anything other than QUALITY flooded L/As which are still, I'm sure, the most cost effective, and the most easily handled. PROVIDED your physical battery installation is secure so the batteries cannot be flung about in a seaway, "floodeds" do not become a hazard due to the boats motion even in very heavy weather. Potential hazards emanate from shoddy electrics, but I'm sure you'll see to any such deficiencies before you set out.

You have not said what your destination is, but I assume that you intend to terminate somewhere in the Caribbean perhaps touching in the Azores and the Bahamas to re-provision. I mention that because you mentioned refrigeration. Why impose such a heavy draw on your necessarily limited battery capacity? I don't know that you are a Norseman, but if you are, you'll be perfectly aware that your forebears (and mine) undertook voyages of longer duration than the one you intend many centuries before refrigeration was invented. Careful attention to provisioning will permit you to cross the Pond with the refrigerator turned OFF for your batteries sake. Once you are in the Caribbean your can always turn it on again.

If your only draws while on passage are navigation and interior lights when required, and those lights are LED lights, you will, I believe, save yourself a lot of aggravation. Construct an "energy budget" defining both the energy consumed by your essential electrical devices, and the energy produced by your means of battery charging. Should you come up short on the charging side after having eliminated all "luxury" draws, you might consider a suitable "stand alone" generator rather than more "sophisticated" batteries, since a generator acknowledges that batteries are only a buffer, not a producer of juice. In a forty-footer you presumably have an engine of 35 or 40 horsepower, fitted with an alternator of 60 or 80 amps. Such an alternator is alright for replacing juice used to start the propulsion engine, but I would not rely on it to replace juice used in housekeeping because the engine is so grossly out of proportion the alternator, and you don't want to run the propulsion engine for hours and hours just to be able to read after dark, let alone to be able to keep your beer cold.

Anyway, you may find a look at the Gylling site and a chat with the Gylling people very beneficial.

Best regards

TrentePieds








.

[Auspicious]

Originally Posted by Sailing4Jesus

If one remembers the Titanic which didn't have enough life rafts, then in my unlearned opinion it is better you have too many Batteries than to get out in the middle of the Atlantic and discover you don't have enough.

Yes, Senior Chief. *grin* I've never had any customer say they thought they bought too many batteries.

[sebathon]

Yes the boat is currently in Portugal but started the trip in Norway. So we are looking for somewhere to order the chosen batteries that offers affordable delivery to Algarve.

Thanks all for the informative responses.

My only concern with FLA is the fact that this storage is directly below our bunk and would prefer something fully sealed. Are AGM or Gel better in the respect ?

Have attached a pic below to show the space I have to work with.

Another option I have found is 4 x Victron Gel 110ah for roughly €1200, Or 3 of the 130ah but not sure if that’s possible to have 3 in parallel?

[gcrothers]

I think you have left it a bit late to think about lifepo4 which is unfortunate, a missed opportunity. Talk to anyone who has " gone the extra mile" and swapped from lead acid to lithium and they will tell you they would never go back. I'm also of that opinion. I swapped 560Ah lead acid for 400Ah lifepo4 at about 1/4 to 1/3 the weight. The 560Ah lead acid is actually only about 280Ah useable when brand new and reduces with age. My 400Ah lithium gives me 320 useable staying within conservative state of charge boundaries. I wish now I had gone up to 600Ah.
On my Transat I consumed about 180A per day, I had 400W of solar and every 3rd day I ran the Genny to recharge the batteries and make water. There is a steep learning curve to get to grips with lithium but we'll worth the effort in my view. Others may disagree but it works for me.