Battery Upgrade or install a wind generator

[Donnybrook]

MaungaMoana,

How much power do you use daily under sail and how many days can you sail with solar today before you have to charge? How much can you get with wind? This info will help make your decision.

I'm going through a similar exercise trying to increase the distance I sail before charging batteries. My situation:

I have four golf-cart batteries (430 amp hours total capacity) and no solar or wind. I can sail around 24 hours before batter is close to 50% discharged and I have to charge. I average 7-10 amps/hour with auto-pilot, lights, electronics, etc.

I want to sail at least 72 hours without charging so I figure I need to return 173 amp hours/day (240 amp/hours used per day * 3 days minus 200 amps/hours usable in battery today).

If I add solar that reliably returns 240 amp hours/day then sun permitting I can sail indefinitely. Anything less then I use battery reserves. As long as I return 173 amp/hours per day I'll reach my 72 hour target.

My understanding is measuring battery state of charge by voltage is only reliable if there's not load on the battery. Do you have a battery monitor that shows how much power you've used/returned?

Have you tried equalizing your batteries to get more life out of them?

[MaungaMoana]

Originally Posted by sailinglegend

If you've killed your 6v batteries in just 3 years you shouldn't be looking at possibly wasting money on Lithium. Sort out your charging systems and battery management first.

We purchased the boat 4 months ago and the batteries came with it as is, so I am unsure of how they were used prior. Do you think there is something wrong with our system in place right now? its pretty basic,

Solar -> MPPT charge control -> batteries
and
Engine -> regulator -> batteries

Originally Posted by ranger42c

Are your current 4x 6V batteries GC2s? So nominal initial bank capacity was approx 440 Ah at 12V?

Could you change to 4x 6V L16s? With nominal initial bank capacity of ~600 Ah at 12V? Taller batteries, but roughly the same footprint...

-Chris

Yep they are GC2s, we have 4 x Crown CR220 (6v 220Ah) so like you mentioned nominal bank capacity 440 Ah at 12V (or usable 220Ah since i understand you dont usually want to bring the flooded batteries below 50%)


In regards to the idea of the 4 x L16s, that’s a solid suggestion that would seemingly save us 20% in costs per Ah compared to the cheap CHINS lithium batteries.

[MaungaMoana]

Originally Posted by Donnybrook

MaungaMoana,

How much power do you use daily under sail and how many days can you sail with solar today before you have to charge? How much can you get with wind? This info will help make your decision.

My understanding is measuring battery state of charge by voltage is only reliable if there's not load on the battery. Do you have a battery monitor that shows how much power you've used/returned?

Have you tried equalizing your batteries to get more life out of them?

In average conditions we are seeing about 5-7A (@12v of course) with our chart plotter, radio, AIS, AutoPilot and running lights. We have seen this go as high as ~9A if the autopilot is doing hard work due to conditions

With a full state of charge we can do maybe just shy of 24 hours before battery goes to 12.0-12.2v which is all good and happy if we can guarantee that the next day is going to be sunny for solar, but sadly we can never guarantee that

Right now we are cruising with a few single overnight sails (which again, is usually ok) but we are planning to do a few more 3-5 night sailing this year and just want to be a more comfortable position (mentally knowing we have juice for the following day if there is no sun) hence the dilemma of to chuck on the wind or just upgrade the battery bank, sadly doing both at the same time is eight now out of budget

Oh and also, no we have never tried to equalise our current batteries, I have let them rest with no load or charge overnight to see what their resting voltage is and it seemed to be all 4 to be all close to each other

[Pete7]

Originally Posted by sailinglegend

If you've killed your 6v batteries in just 3 years you shouldn't be looking at possibly wasting money on Lithium. Sort out your charging systems and battery management first.

Either the previous owner or the boat sitting waiting to be sold killed the batteries.

The price of lithium should also include the extra wiring and heavy copper cables are now expensive compared to what I remember. Also any changes to the MPPTs etc and a DC>DC charger.

Perhaps for now replace with lead-acid and increase the solar for the next couple of years to see if they last any better.

Pete

[stormalong]

Originally Posted by MaungaMoana

We purchased the boat 4 months ago and the batteries came with it as is, so I am unsure of how they were used prior. Do you think there is something wrong with our system in place right now? its pretty basic,

Solar -> MPPT charge control -> batteries
and
Engine -> regulator -> batteries





Yep they are GC2s, we have 4 x Crown CR220 (6v 220Ah) so like you mentioned nominal bank capacity 440 Ah at 12V (or usable 220Ah since i understand you dont usually want to bring the flooded batteries below 50%)


In regards to the idea of the 4 x L16s, that’s a solid suggestion that would seemingly save us 20% in costs per Ah compared to the cheap CHINS lithium batteries.

Not familiar with Crown brand. Did the batteries sit for a long time without being charged before you bought the boat? That is a sure way to kill flooded lead acid batteries. How do you know they are only three years old? Was the age from the date code or is that what the previous owner said? There are a lot of poorly made batteries on the market, Crown may be one of them.

[Bill O]

Originally Posted by stormalong

Not familiar with Crown brand. Did the batteries sit for a long time without being charged before you bought the boat? That is a sure way to kill flooded lead acid batteries. How do you know they are only three years old? Was the age from the date code or is that what the previous owner said? There are a lot of poorly made batteries on the market, Crown may be one of them.

We have Crowns and they have lasted a long time for us. Ours are slightly larger (taller) and are 235ah 6v golf cart batteries.
Most of the time we see people forgetting to add distilled water and the cells go dry, killing the batteries. Isn't too difficult to set up a schedule to routinely water them.

[ohthetrees]

I have solar and a very high-quality D400 generator. I think it’s a great wind generator, yet I’m thinking I’m taking mine off as it sometime shades my solar panels, and is weight up high. I think wind generators have completely been overtaken by solar, unless you are trying to do high latitude stuff. My advice would be to upgrade your solar, and if you are on a budget, only get one 300 amp hour lithium battery. 300 amp hour lithium will probably perform much better thann all that lead acid you have now.

[Cheechako]

Originally Posted by MaungaMoana

Yes BUT. The current flooded batteries are old, a test we did was plugging them into stable shore power with our battery charger until they were full, and then let them rest with no load or charge for 12 hours and they settled at 12.4v (showing they are 'well used')






Totally understand and you are right, but this is true only when we are sailing and there is no sun (nights or really overcast days)
While there is a nice sunny day we solar is magical powering our AP and charging our old flooded batteries. But once the sun sets and we stop generating we could keep the AP on for maybe 6-8 hours before we see the batteries reaching the 12.0-12.2v range

Battery capacity always has to be put back in somehow. More batteriy capacity means more charging.
-Running the engine with a good alternator/regulator for an hour at night while on passage is an option.
-Wind charger may be an option, I found mine less than useful for keeping the batteries full though... and that was without running the AP, just sitting at anchor.

FYI: I bought two new batteries and tested resting voltage after sitting over night after full charging. They read 12.45 and 12.46. So you are not too far off.

[AndyEss]

Originally Posted by ohthetrees

I have solar and a very high-quality D400 generator. I think it’s a great wind generator, yet I’m thinking I’m taking mine off as it sometime shades my solar panels, and is weight up high. I think wind generators have completely been overtaken by solar, unless you are trying to do high latitude stuff. My advice would be to upgrade your solar, and if you are on a budget, only get one 300 amp hour lithium battery. 300 amp hour lithium will probably perform much better thann all that lead acid you have now.

This.

Getting rid of all that lead will lighten your boat - and your back will thank you many times over by switching to LFP.
I haven’t checked the price of replacement spines recently.

[waterman46]

Originally Posted by Bill O

We have Crowns and they have lasted a long time for us. Ours are slightly larger (taller) and are 235ah 6v golf cart batteries.
Most of the time we see people forgetting to add distilled water and the cells go dry, killing the batteries. Isn't too difficult to set up a schedule to routinely water them.

You can install automatic watering system but really AGM is a better choice than FLA if you are not able to tend to your batteries weekly.

[leandroflaherty]

Both. Start with the batteries.

[sck5]

If you are going to be sailing in the Eastern Caribbean for the foreseeable future and therefore you are going to be spending a lot of time at anchor, then bear in mind that most long term anchorages and most of the marinas are located on the lee side of the islands and so are not exposed to the trade winds much, if at all.

Add to that the fact that you are unlikely to go on a lot of multi-day sails if you are island hopping. For those occasions when you DO go on a longer passage just run the motor for a couple of hours once or twice and you will be good. You will be becalmed a lot of the time anyway as you sail in the lee of the higher islands and will have to motor. I know that isnt the purist way of doing it and isnt the way I would do it if I were, e.g. crossing the Pacific. But it worked fine in the Caribe (and my boat had the same solar as yours and likely much the same autopilot, radar, etc.)

Wind gens are less noisy now than they used to be. But they can still eat up loose lines and shade solar panels. Solar panels on the other hand are in their happy zone at any latitude far enough south to be in the Caribbean.

FWIW the two big draws on power while under way were the autopilot and radar. I found I didnt usually need the radar most of the time because visibility is typically excellent and traffic not that heavy, esp. the further south you get or at night (when visibility is often still excellent). I actually used it more often to see who was the winner of the game "How far away is that object do you suppose?" than I did to watch other boats.

[Phyrcooler]

Originally Posted by Cheechako

Battery capacity always has to be put back in somehow. More batteriy capacity means more charging.
-Running the engine with a good alternator/regulator for an hour at night while on passage is an option.

This ^^^ If you’re happy with your system at anchor, and only issues are those overnight passages a few times a year. Assuming you have a reasonable charging system on your diesel - just fire it up for an hour. Bonus is hot water to shower and wash dishes in the AM The 5 - 10 hours/year of engine usage and 3 - 7 gallons of fuel are negligible. Especially compared to the potential money spent on upgrades.

[jim King]

If you are in the Caribbean I'd go with the wind generators. The wind seems to be fairly consistent from the east at 10 to 20 mph.

[Bill O]

Originally Posted by waterman46

You can install automatic watering system but really AGM is a better choice than FLA if you are not able to tend to your batteries weekly.

Weekly?? My schedule is at the beginning of the month just for ease of remembering when to do it. In reality, could easily go every 2 months to add water.
Fairly easy to add water w/o an automatic watering system even w/8 golf cart batteries (940ah). An added benefit of manually watering the FLA batteries, one can see if any particular cell is possibly going bad which could be missed w/an automatic watering system.