Battery Upgrade or install a wind generator

[roverhi]

Don't know what the exotic batteries cost but lead acid are really cheap. Obviously your autopilot is an energy hog and needs more of everything, battery storage, charging, etc to keep up with its demand. For the Caribbean wind generators can work at anchor because of the windy anchorages but aren't a good generating source for most other areas of the world. They really require 15k wind to generate much electricity.

Another possibility is a wind self steering. Auxillary rudder systems like WindPilot Pacific Plus or Hydrovane work well and can act as a replacement for the boat's rudder should something happen. They don't eat electrons and can be set up to steer magnetically with a tiller pilot for ultra low drain auto pilot. They aren't cheap but very low, if any, maintenance, silent and no electrons required.

[Adelie]

Originally Posted by 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.

4 T-105’s at 12v is 450Ahr new. That’s 225Ahr usable.

410W of panels should provide about 136Ahr/d normally.

AP should be drawing about 50Ahr/d if you’ve trimmed you sails to be balanced or almost balanced.

A fridge is about 50Ahr/d

What instruments do you really need on passage?

What other demands are there?

If you are running both AP & fridge you probably are exceeding your generation. Add another 100-200W solar on its own controller and see what happens.

[Adelie]

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.

How is an AGM a hood choice for house loads on a sailboat?

They stand up to vibration better than FLAs but a sailboat is not a high but ration use.

They can accept high charge currents but I order to do so you need a high output alternator which would also require a depending belt. Both of which are high ticket items all to save on the order of 30min per charge cycle to 50%.

Maintenance free cuts both ways. If you abuse the battery you can’t add water to maintain it.

What are the down sides to AGM?

They really don’t like PSoC operation. If you can’t get them to 100% almost every cycle, lifecycles suffers.

If you’ve gone down to 50-60% you really need to be bulk charging at high amps or cycle life suffers. High amps as in 0.2C minimum, 0.3-0.4 much better. Most people that talk about getting 5-7-10yr from an AGM bank, if you talk to them about the rest of the system, they have very large banks and a lot of charging sources and capacity. They rarely go below 70% and they get fully charged most days.


If I had problems with access to perform maintenance or had trouble remembering I would get Gels.

[Locquatious]

It seems to me that your needs may change when you get to the Caribbean. The auto pilot, once you are there, becomes less important than refrigeration, keeping healthy batteries, running your electronics, and making water. But that depends on what you plan, or end up doing.
Some do the Caribbean zipping up and down island. They need the autopilot. And they probably need fuel.
Some find a bay of anchored/moored "cruisers" and let their anchor chain grow barnacles. They invest in solar panels or wind generators depending on the local conditions. They add batteries to keep the bank healthy.
We have solar panels and wind generators (Kiss and Kiss Extractors). We also have supermarket refrigeration with cold plates, so we need to run a generator. We avoid using an inverter.
We run computers and internet electronics with DC-DC controllers. They are 95+% efficient. Inverters are probably less than 35% after all the conversions.
If we need water, we move our anchorage to a location where there is more wind. There our 12V water maker refills our 400 gallon tankage in a few days.

400 gallons!.. you say. Well yes. Your decisions regarding solar, wind, batteries depend on the capacities of your boat, the location of your boat, your cruising lifestyle, your electrical efficiency knowledge, your electrical diligence and other inclinations. There is no fixed answer.

[Frankly]

All these different solutions and not one suggested looking at the type of auto pilot (other than a vane). If you drive directly from the wheel/ shaft the energy requirements are reduced significantly compared to typically driving the rudder directly. Driving my IP rack and pinion from the wheel shaft my biggest power consumption in moderate conditions (other than frig) is listening to Jimmy Buffett on the stereo (no I am not deaf).


Frankly

[BillKny]

Originally Posted by Locquatious

Inverters are probably less than 35% after all the conversions.

I don't know where you came up with that number, but it is VERY, VERY far off in any modern system.

Our actually measured value show we get 100 Watts out for 108 watts in, (that's 92%) and better than that at higher draws. Over the last few years in total we have pushed 595kW-hrs into our batteries and pulled 518 kW-hrs out, for an overall battery efficiency of 85%. As I figure it, from charging source to AC user we are close to 80%, with most of that lost in battery inefficiencies, which would be identical if we were powering a DC load.

I am not sure WHERE you think you are losing 65% of your power, but looking at it more accurately you might find inverters are a better choice than you think.

We routinely use inverters to power loads of 3000 Watts. If we had an inverter efficiency of as low as you quote, there would be parts of our electrical system glowing red hot with the wasted power.

[SaltyMetals]

Three points not so far mentioned in this thread.

If not already done, change ALL you lights (except perhaps the steaming light) to LED. THis includes the nav lights.

When using the AP you could set the Response level down to the minimum which would slightly reduce the amount of current used by the AP

At night or poor vis when using the radar you could set it to scan intermittently instead of leaving it ON all the time in Transmit mode.

I agree with earlier comments that it is best to max the number of solar panels installed. I have a windgen (Rutland 400) that will generate at least 20A at 30 knots of wind but typically in the Med it is only providing 15% of the power input compared to my 2 x 150W solar. Possibly 30% in the winter. So go for max solar depending on space. One of my 150Wpanels is zipped onto the rear fixed part of my bimini.

Best of luck with your "new" boat.
Andrew

[Locquatious]

[QUOTE=BillKny;3475386]I don't know where you came up with that number, but it is VERY, VERY far off in any modern system.

Thank you for the correction. I was thinking of our older inverter which I used as an electronic load for wind generator research on the boat. I was trying to keep the batteries at constant voltage. Just turning the thing on with no load would easily dissipate the wind generator power in low to moderate winds.

But DC-DC converters are still more efficient compared to going from DC to AC and back to DC.

For example, if you have solar or wind generated DC power converted to AC at 85% and then convert the AC back to DC to charge your computer (~72% average for modern chargers VI rated below 5W) you have 0.85 X 0.72 =61% efficiency. You could achieve the same thing with a 12V to 15V DC-DC converter and be in the 95% efficiency range. The AC wall plug chargers drop in efficiency toward the end of computer battery charging. At 5W the efficiency is ~78% while at 1W it drops to 67%.

Keep in mind that people tend to leave the wall chargers plugged in even when disconnected from what they are supposed to charge. And electronics like TV's and microwaves create a parisitic load, even when they are not operating. If one has one boat inverter, they have to unplug or switch off the unused electronics. You may be energy aware, but others in your boat-hold are likely oblivious regarding parisitic loads.

[salfarina]

I agree with BillKny. Minimize your consumption first ( wind vane), LED lights, tablet chart plotter. Then re-assess your requirements vs capacity.

[lordgeoff]

Originally Posted by 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.

If your batteries need charging while sailing at night then run the engine for an hour. A Lt or two of diesel is a pretty flexible solution. How often do you cruise through the night?

[Painless]

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

Remember that the charge curve on LifePo4 batteries is much steeper than your FLA batteries. They will absorb every bit of energy
from your panels whereas the FLA have a very flat curve to get to float.

[leehaefele]

1) Replace the batteries. 4 good GC2 batteries will definitely sail overnight, if you start with a full charge.
2) Replace or convert engine alternator to one that has a 3 stage regulator. This will cut engine charging time from 6 hours to 2 hours.
3) Install battery monitor, otherwise you do not know your state of charge.
4) Consider adding more solar. Note, MAKE SURE THERE IS NO SHADE ON YOUR SOLAR PANELS. Move the boom as needed.
A small generator and a 60+ amp 3 stage charger is another option.

[Lateral Hazard]

Our surveyor is a very wise old sailor and power boater who knows more than anyone I have met. When dreaming what I wanted to do with the boat, Lithium batteries, wind generator etc he said.
1. Cost of lithium batteries and component replacement is way to high right now. Forget it
2. John, fix the problem you have now and figure out how to lower consumption before trying to find ways to increase capacity. Your problem now is the batteries. Replace with AGM.
3. Throwing money at things rarely works and what you buy ends up in the garbage. Keep it simple. Solar works, Wind generation is so so and having good batteries is a must.

[Riggerman]

40 years of boating here with 20 living on the hook. Forget the wind generator. yes they are an add up, but they are for top off at best. I have tried Aerogen 600 I now have a D400 and yes they help but that is about it. Lithium give you better usage of the existing capacity. If it was Me, I would go as big solar panel I can go, with as many lithium I could fit. 4 X 6volts T105 were replaced by 8 or 2 time 360 amp lithium for a total of 720 amp that can be used up to 80%.

[Jimmyhenry]

We have a Superwind generator and 300 watts of solar. On extended multi day passage (Sth Pacific) the wind generator provides ample power for all electronic and AP. we have 4 x 6 volt lead acid batteries. 540 amp hours. Never get below about 80%.