Illustrated Guide to Solar Installations on Boats

[MLOI]

Originally Posted by bcboomer

Awesome!

This is much better looking than the rigid panel bimini I've been considering.
Are your panels aluminium backed?

No - just the normal PE or whatever the flexible panels are made from.

It would be more robust if I added Ali strips under the panels, and even more so if I added ali channel between the bimini bows. Idea would be to have shallow ali channel - maybe 25ish wide by 20 deep - with holes at each end that align with the grommets. Glue the panels to the channel and it would both take the tension off the panels and ensure that they were unable to flap.

But I didn't do it - in part to see if this simple setup would work, in part because I ran out of time.

I can take the panels down in about 5 minutes each, but it takes a good hour or so to set them up again and get all the tension even. And it took about 4 hours of assembly and disassembly to get the height right, cutting the bows a little bit shorter each time.

Note that if you go this route that it doesn't do a great job of keeping water off the helmsman. The gap between the panels seems to let a whole lot of rain fall on my head

Mike

[Pelagic]

Originally Posted by MLOI

Note that if you go this route that it doesn't do a great job of keeping water off the helmsman. The gap between the panels seems to let a whole lot of rain fall on my head [emoji2]

Mike

That was my first thought as well Mike, but a nice lightweight installation.

Have you thought about modifying the tubing with additional rail so that you can stretch a watertight Bimini cloth under the solar panels?

[MLOI]

Originally Posted by Pelagic

That was my first thought as well Mike, but a nice lightweight installation.

Have you thought about modifying the tubing with additional rail so that you can stretch a watertight Bimini cloth under the solar panels?

Nope. I don't dissolve in water, I've tested that thoroughly

Besides, as you can see from the photo, we have a Golem that does all the driving anyway. Anytime we are driving, it's because we want to, or because Golem has given up... which it has been my experience only happens when it's bumpy and the rain is coming in sideways and the sea coming across the bow anyway. When I've paid any attention to rain coming between the panels, it has been light rain in warm conditions, and I've just moved sideways a bit. Mostly I've been driving for fun, if it actually annoyed me I could put on waterproofs, shorten sail, put on the autopilot, or all of the above.

Where we have cruised I care a heap more about keeping the sun off, which this does. If I was sailing somewhere I wanted a bimini to keep the rain off, I'd want to go the whole way to a pilothouse design. Or move somewhere warmer.

Mike

[waeshael]

Here are my photos and guide to Solar that I use on my boat.
Solar

plus boat details and RF issues and so on on other pages.

This is private non-commercial site for my friends and family.

[twohapence]

So........ Photos to follow.

I have fitted 4 * 150 watt panels to my Lucia 40 catamaran. They are 24 volt semi flexible panels bonded to the fibreglass. They're wired in series/parallel to give me 48 volts. This may, or may not be the right thing to do but my reasoning is that efficiency of the panels drops as they get warmer. A nominal 12 volt system would stop charging the batteries as the voltage drops due to temperature or shading. A 48 volt system will still charge. 100 volts "feels" like too many in a marine environment. I may add diodes later.

The key is "Temperature coefficient Pmax" and a panel on a roof may well be losing 10% of its efficiency or more during peak sun. Add in a little shading and a 12 volt system may well stop charging.

The panels are connected to a Victron Smart Solar 100/50. Two are mounted in the built in "tray" behind the mainsheet track. Two on the roof.

I have fitted 2 * 200AH lithium batteries in place of the 300 AH LA house bank. Each battery is comprised of four Winston LiFePO4 cells with a Smart BMS installed. I added a starter battery for the starboard engine, it previously used the house bank. I then fitted two Sterling 60 amp Baterry to Battery Chargers, one for each alternator. These trick the alternator regulator into supplying power and are current limited so that the regulator isn't running the alternator at full tilt all the time which can lead to premature failure.

I also have a Victron 3000VA inverter charger. Interestingly this can't be set to a Lithium profile using the dip switches. You need to have a Victron VE Bus to USB interface. My supplier lent me one so I could configure the system. Thanks Andy! Products – Power Saving Solutions if you need great prices and fabulous service.

The system works well although there was a scare half way across the bay of biscay when the house bank died..... The solar charge controller had gone into float mode when connected to shore power and stayed there even though the voltage was dropping. Turning the engines on so the B2B chargers started supplying amps and then connecting to the solar charge controller via bluetooth and turning off charging and then turning it back on again kick started the system into life again. I need to talk to Victon about this.

Since then it's been running fine. Keeping the fridge cool and running the watermaker.

The battery cells and management system are a little bit "Heath Robinson" and in retrospect the ease of installation of Victron LiFePO4 batteries probably would have offset the fact they cost twice as much as the Winston cells. (£1,000 for a 200AH battery and BMS from EV-Power. £2,250 for the Victron 200AH unit with built in BMS and interfces to the Victron network.)

The engine compartment is just a little bit cramped now....... but the plan is long term cruising and staying away from Marinas reduces costs. That means being as self sufficient as possible for power and water.

[CatNewBee]

Congratulations to your LFP install!

What bugs me, is your float setting of the solar controller. Maybe you read too many scaring stories and set the value too low. Otherwise FLOAT would have kept your batteries at 90% as long as the sun shines (and your fridges/electronics running on solar during daytime).

Maybe re-consider your settings of the chargers....

Mine is set to 13.6V FLOAT. I use a reduced ABSORPTION to 14.0V, so the battery is charged only to approx. 95% (3.5V per cell). Manual equalisation would kick it to 3.60 Volt at 14.4V. It is very conservative, but I have a nominal 1000Ah bank, so 100Ah less does not hurt.

Another problem may be your serial wire up and partial shading underway from the boom, sails or sheets, that can jeopardize any significant power output.

[CatNewBee]

[noelex 77]

Originally Posted by twohapence

The system works well although there was a scare half way across the bay of biscay when the house bank died..... The solar charge controller had gone into float mode when connected to shore power and stayed there even though the voltage was dropping. Turning the engines on so the B2B chargers started supplying amps and then connecting to the solar charge controller via bluetooth and turning off charging and then turning it back on again kick started the system into life again. I need to talk to Victon about this.
.

The Victron controllers have a very unusual battery charging algorithm.

The bulk return voltage, or the voltage where the controller will return to bulk phase needs to be set very high for the Victron controller algorithm to work with lead acid batteries. The bulk return voltage is not independently adjustable, as it is on some controllers, but it uses the float voltage for this setting.

So bulk return voltage = float voltage.

The requirements for lithium batteries are very different to lead, but it is important to realise that with the Victron controllers if you set a low float voltage you are also setting a low battery return voltage. This problem is further complicated because the battery voltage with lithium will not decrease as significantly as it does with lead when the batteries are subject to high loads or low SOC.

[CatNewBee]

yes, maybe you just post your settings, then very likely we can sort it out some how.
After lots of testing and tuning I found for my Winston / Victron MPPT combination a FLOAT of 13.6V ideal (it are at the battery round 13.4..13.5V), so the battery remains around 93..95% SOC and solar supplies all electric on board.

[twohapence]

Originally Posted by CatNewBee

yes, maybe you just post your settings, then very likely we can sort it out some how.
After lots of testing and tuning I found for my Winston / Victron MPPT combination a FLOAT of 13.6V ideal (it are at the battery round 13.4..13.5V), so the battery remains around 93..95% SOC and solar supplies all electric on board.

Finally taken my boat over from the delivery crew. And catastrophe............!!!!!!

When I arrived on the boat the delivery crew had left, all the electrics were turned on but I had no power. Lights out across the boat. It was pitch black and while searching for my head torch I discovered the hard way that the safety cover had come off my razor.

The engine start batteries are LA and isolated from the house supply. The B2B chargers keep them isolated. So I started the starboard engine and it the B2B charger started doing its stuff. There was a faint glimmer of light and then eventually the voltage rose enough to let the Victron battery protect pass some volts into the boat. Only for it to die a few moments later.

I got out the shore power cable and plugged that in. Nothing. Eventually found out you needed a prepaid card to load credit onto the meter. Once sorted I eventually had 12 volt power from the inverter/charger. Immediate crisis over I bandaged my finger and headed to bed.

The following morning I had a good look at the system. To recapitulate I have two banks of 4 200AH Wiston cells with a smart BMS from EV Power. These are connected in parallel to give me a 400AH house bank. The BMS on one of the batteries was only showing one cell as being active. The other cells weren’t registering. I had a quick look and only one cell had a flashing green light. On the other battery all four boards managing the individual cells were doing a Xmas tree impression and flashing away merrily.

Then I looked a little closer. On one of the batteries three cells were massively distorted. One was looking normal. I put a multimeter across the cells and shock horror. Three cells in that battery were reading 4.4 volts. The last one was reading 0.001. Fearing the worst I removed the damaged cells from the boat.

The second bank operates just fine and the smart BMS is keeping the cells balanced. The screenshots show the BMS and the Victron charge controller. It is only just sunrise....

My suspicion is that one of the cells in the bank failed and effectively left a bank of three cells. The BMS also failed possibly because it was passing too much current trying to maintain v max at 3.8.

The second bank was operating normally so was happy to accept a bulk charge at 14.2 volts. This is 3.55V per cell. The broken bank was trying to accept charge at an effective voltage of 4.73. Result? Swollen and damaged cells. In retrospect it was not a good idea to have the two batteries in a single bank. I think a tipping point was reached and the voltage dropped enough to kick in the battery protect, isolating the batteries. Interesting to note that the day before I arrived there was no charge supplied to the battery by the solar charge controller.

The response from ev-power was informative but unhelpful. I suspect I need further discussion as I think the failed cell caused the issue.

———————————————————-

From EVPower a.s. - Tech Department


Hello,

we are sorry for invenconience.

Thats a horrible situation for all cells.

4.4V - all 3 cells are damaged. If you disconected the charger what is the
voltage? I reccomend discharge somehow ( maybe with some lightbulb )

0 V means, the cell is damaged. You can you try to revive the cell with a
laboratory supply. Set the 3V and current maximal 1A and slowly charge to
the level where is possible charge with single cell charger.

You do not have to worry about the fire. LIfePo4 is safe technology.

But I mean this situation is bad for all cells in this pack, the cells were
damaged, and even if you manage to get them into shape, their life and
ability to function well will be shortened ...

———————————————————————————-

[CatNewBee]

Originally Posted by twohapence

Finally taken my boat over from the delivery crew. And catastrophe............!!!!!!

When I arrived on the boat the delivery crew had left, all the electrics were turned on but I had no power. Lights out across the boat. It was pitch black and while searching for my head torch I discovered the hard way that the safety cover had come off my razor.

The engine start batteries are LA and isolated from the house supply. The B2B chargers keep them isolated. So I started the starboard engine and it the B2B charger started doing its stuff. There was a faint glimmer of light and then eventually the voltage rose enough to let the Victron battery protect pass some volts into the boat. Only for it to die a few moments later.

I got out the shore power cable and plugged that in. Nothing. Eventually found out you needed a prepaid card to load credit onto the meter. Once sorted I eventually had 12 volt power from the inverter/charger. Immediate crisis over I bandaged my finger and headed to bed.

The following morning I had a good look at the system. To recapitulate I have two banks of 4 200AH Wiston cells with a smart BMS from EV Power. These are connected in parallel to give me a 400AH house bank. The BMS on one of the batteries was only showing one cell as being active. The other cells weren’t registering. I had a quick look and only one cell had a flashing green light. On the other battery all four boards managing the individual cells were doing a Xmas tree impression and flashing away merrily.

Then I looked a little closer. On one of the batteries three cells were massively distorted. One was looking normal. I put a multimeter across the cells and shock horror. Three cells in that battery were reading 4.4 volts. The last one was reading 0.001. Fearing the worst I removed the damaged cells from the boat.

The second bank operates just fine and the smart BMS is keeping the cells balanced. The screenshots show the BMS and the Victron charge controller. It is only just sunrise....

My suspicion is that one of the cells in the bank failed and effectively left a bank of three cells. The BMS also failed possibly because it was passing too much current trying to maintain v max at 3.8.

The second bank was operating normally so was happy to accept a bulk charge at 14.2 volts. This is 3.55V per cell. The broken bank was trying to accept charge at an effective voltage of 4.73. Result? Swollen and damaged cells. In retrospect it was not a good idea to have the two batteries in a single bank. I think a tipping point was reached and the voltage dropped enough to kick in the battery protect, isolating the batteries. Interesting to note that the day before I arrived there was no charge supplied to the battery by the solar charge controller.

The response from ev-power was informative but unhelpful. I suspect I need further discussion as I think the failed cell caused the issue.

———————————————————-

FromEVPower a.s. - Tech Department


Hello,

we are sorry for invenconience.

Thats a horrible situation for all cells.

4.4V - all 3 cells are damaged. If you disconected the charger what is the
voltage? I reccomend discharge somehow ( maybe with some lightbulb )

0 V means, the cell is damaged. You can you try to revive the cell with a
laboratory supply. Set the 3V and current maximal 1A and slowly charge to
the level where is possible charge with single cell charger.

You do not have to worry about the fire. LIfePo4 is safe technology.

But I mean this situation is bad for all cells in this pack, the cells were
damaged, and even if you manage to get them into shape, their life and
ability to function well will be shortened ...

———————————————————————————-

This seems to be a dessign error. If you have 2 batteries and want to connect them in parallel, each string needs a BMS and a solenoid to disconnect the battery if a cell fails. both signals - stop charge AND stop discharge must drop the battery, because you cannot implement 2 independent busses on paralleled batteries (charge bus / discharge bus), there are cross-battery currents.

I assume, you have connected both bms in parallel to the solenoids. One gives the signal OVERCHARGE, while the other signals, ALL OK. The second wins.

There are 2 ways to circumvent this. either you use complete isolation of the batteries with separate soleniods etc, or you parallel the cells with a single BMS and interruptor logic.

Really redundand systems need way more electronics for proper isolation, it is not just put two batteries in parallel. BTW, it is the same for all kind of batteries, you fry your GEL batteries exactly for the same reason, if one cell gets short.

[foggysail]

Originally Posted by CatNewBee

This seems to be a dessign error. If you have 2 batteries and want to connect them in parallel, each string needs a BMS and a solenoid to disconnect the battery if a cell fails. both signals - stop charge AND stop discharge must drop the battery, because you cannot implement 2 independent busses on paralleled batteries (charge bus / discharge bus), there are cross-battery currents.

I assume, you have connected both bms in parallel to the solenoids. One gives the signal OVERCHARGE, while the other signals, ALL OK. The second wins.

There are 2 ways to circumvent this. either you use complete isolation of the batteries with separate soleniods etc, or you parallel the cells with a single BMS and interruptor logic.

Really redundand systems need way more electronics for proper isolation, it is not just put two batteries in parallel. BTW, it is the same for all kind of batteries, you fry your GEL batteries exactly for the same reason, if one cell gets short.

In real life, I have never came across battery banks provided with isolation circuitry, maybe they can be found in very high reliability military applications. The above quote reminds me of something asked me by a senior engineer when I first started in electrical engineering circuit design. He asked “are you designing a brick ****house?”

[john61ct]

This subtopic on "LFP engineering and risk avoidance" really deserves a new thread.

Could twohapence request the mods split it off, or just copy / paste to start one off, then post the link to it here?

[GrowleyMonster]

Originally Posted by a64pilot

I have 1KW on my IP 38, no pics yet and no real data on output etc yet either as I'm tied to a dock with shorepower. Should get some pics this weekend.
However there is a budget way to do things, I bought four left over panels from a large installer and paid 50c a watt, so I have $500 in panels, the frame I built out of scrap 2024 T3 extrusions so that was free and I paid about $500 for my Outback 80.
I have I think about $300 in wire, connectors / fuses etc. and I went overboard and used a fused / lightning protected combiner box.
So I think I have about $1300 in a Kilowatt of Solar, could have done it for $1,100 if I had not gone with the combiner box.

So it can be done on a budget

I gotta say, your setup is a pretty darn good bang for the buck. Close to what I hope to do, which is crowd 2kw on my dismasted 27'er, on a hard canopy covering the whole boat and overhanging the stern a bit, too. I hope to get my panels cheap, by buying a whole pallet. GF wants solar on the roof (for hurricane outages) and any overs I should be able to sell pretty quick at my cost. Canopy will be fiberglass over something something not decided yet. I am a budget oriented guy too... my electric repower cost me about $2400 including 10.56 kw/hr bank so we are on the same wavelength I think. Thanks for the inspiration.

[Bleemus]

Originally Posted by GrowleyMonster

I gotta say, your setup is a pretty darn good bang for the buck. Close to what I hope to do, which is crowd 2kw on my dismasted 27'er, on a hard canopy covering the whole boat and overhanging the stern a bit, too. I hope to get my panels cheap, by buying a whole pallet. GF wants solar on the roof (for hurricane outages) and any overs I should be able to sell pretty quick at my cost. Canopy will be fiberglass over something something not decided yet. I am a budget oriented guy too... my electric repower cost me about $2400 including 10.56 kw/hr bank so we are on the same wavelength I think. Thanks for the inspiration.

That sounds like an interesting boat. Converting a sailboat to a power boat?