Battery Upgrade or install a wind generator

[MaungaMoana]

Hi all.

We are in a bit of a dilemma of what we should upgrade

Currently we have (3 year old) 4 x 6v flooded batteries as our house batteries (in 12v configuration) and 2 x 205W solar panels.

While on anchorage we are totally ok with their capacity, however while sailing (especially while overnights) we see the batteries go super low when using auto pilot and our sailing electronics, so we end up hand steering in our shifts

Our criteria is to be able to have the autopilot running "all the time" while sailing in regards to power draw which is why we figured we needed a wind generator. (we are going to be in the Caribbean for the foreseeable future)

My Question, should we go with a wind generator installation or should be simply upgrade our batteries and carry on using solar

Option A)
Install D400 wind generator $2100 USD + mounting costs

Option B)
2 x 300Ah cheapo lithium batteries in parallel $2200

Both options would be ending up in similar price ranges hence why we arent sure which we would benefit from the most.

[Rod Headlee]

Option A, you won't regret it. It was a pain to install but quiet and efficient. We have had ours for 10 years, sailed from Annapolis to SF and SF to Mexico. We only have 1-140 watt panel. If you have wind, you have power.

[jt11791]

I would go for better batteries and, if needed, more solar. I've always been disappointed by my windgen's output. Even if it made more power, I would not spend money on another one. In fact, I am considering removing mine because it sometimes shades the solar panels and probably costs me more power than it ever makes.

[wholybee]

A single 300Ah Lithium would be more usable power than 4 T-105 6V batteries. Even more so if the Lead Batteries are 3 years old and have been abused.

So option 3 would be 300Ah of Lithium, and more solar. (or wind gen)

[Off Trail]

I think you answered your own question. If you need to run the AP "all the time" and you can't now, your goes-in energy isn't keeping up with your goes-out. So more battery capacity will only delay the inevitable. Lithium does have higher efficiency so you would get some gain but likely not enough to change the situation.

So you need more energy coming in. Wind, solar or fossil fuel.

[Dsanduril]

When your batteries go "super low" are your current solar panels able to get them fully charged before the next evening?

If yes, then your current panels are keeping up with total energy usage and more batteries will reduce your depth-of-discharge and give you more buffer. Of course, if you will be using the AP more after this upgrade then your total energy usage will increase, so factor that in.

If no then your current charging system is not keeping up with total load and you need more charging capacity. In that case wind gen or more solar might be suitable depending on how/where it gets mounted, etc.

We have settled on solar only (have had both solar and wind in the past), but we have room for the solar. Wind gens, IME, generally deliver less than you expect but can still be quite useful, especially in providing at least some charging at night.

[BillKny]

You should never be making a choice between more battery OR more generating capacity. to solve an electricity problem. If your generating capacity is not adequate to keep up with your usage, you will eventually run down even the biggest battery bank and then struggle to fill it back up again. It is kind of like putting in a bigger gas tank to save money on fuel, it doesn't work that way.

Sounds to me like you need to either reduce your usage, or increase your generating capacity or both.

For the kind of money you are looking to spend you could install a wind vane and get a more reliable steering system, and cut your passage power consumption dramatically.

Do remember, that wind generators will make VERY little power when sailing downwind.

If you do go with wind generator you will almost surely need the battery expansion as well since wind power is very irregular.

[MaungaMoana]

Originally Posted by Dsanduril

When your batteries go "super low" are your current solar panels able to get them fully charged before the next evening?

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')

Originally Posted by Off Trail

I think you answered your own question. If you need to run the AP "all the time" and you can't now, your goes-in energy isn't keeping up with your goes-out.

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

[SVTatia]

Originally Posted by BillKny

You should never be making a choice between more battery OR more generating capacity. to solve an electricity problem. If your generating capacity is not adequate to keep up with your usage, you will eventually run down even the biggest battery bank and then struggle to fill it back up again. It is kind of like putting in a bigger gas tank to save money on fuel, it doesn't work that way.

Sounds to me like you need to either reduce your usage, or increase your generating capacity or both.

For the kind of money you are looking to spend you could install a wind vane and get a more reliable steering system, and cut your passage power consumption dramatically.

...Do remember, that wind generators will make VERY little power when sailing downwind.

If you do go with wind generator you will almost surely need the battery expansion as well since wind power is very irregular.

This^^^^
Your option C.

[RaymondR]

I removed the wind generator from the boat I now have a short time after I purchased it. It was the second wind generator I have had and my experience with both of them was unsatisfactory. The damned wind just would not blow when I wanted it to.

I then used an inverter genset with a battery charger for about two years until the electronics on the genset went out and my experience of poor reliability with the genset decided me to disabuse myself of it. One of the times the batteries most needed an alternative to the solar panels for charging was when the sky was overcast and it was raining for a couple of days. Keeping the genset dry whilst avoiding carbon monoxide poisoning proved difficult and I think water ingress into the genset electrics was the failure mode.

I then rigged up a small Honda gas engine with two belt driven auto alternators for battery charging and so far am satisfied with it although it is very noisy.

I try to avoid overnight sailing but on the couple of occasions I have had to do so have found the good charging characteristics of the small gas engine driven charger allowed me to get by with a single charging session during the dark hours.

[Bill O]

Option D is possibly a hydrocharger. Downside is you need to be able to do at least 6kts for a decent output.

[GreenWave]

I think the answer is a little of both. Add more battery capacity and add more solar. While you could add wind gen, I think Solar is a better option.

[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.

[stormalong]

Originally Posted by sailinglegend

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

:
Good point. I get eight to ten years from my six Trojan T-105s. If you are only getting 12.4 volts on fully rested three year old batteries they have not been properly maintained or they were low quality to start with.

When I did long ocean passages I had solar, wind and hydro. The three together provided all the power I needed, including 24/7 autopilot. Contrary to another post, in strong downwind tradewinds wind generators produce a lot of power.

[ranger58sb]

Originally Posted by MaungaMoana

Currently we have (3 year old) 4 x 6v flooded batteries as our house batteries (in 12v configuration) and 2 x 205W solar panels.

Originally Posted by MaungaMoana

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')

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