8 x 200ah batteries die after 18 months

[vas]

Yes, I ran that calc.
I also read the Victron MPPT manual.
I may have said this before but there is a small catch when using a small number of panels.
The Victron MPPT controller requires that the panels generate at least 5 volts more the battery voltage before the MPPT controller starts.
After that, it only needs 1 volt more than the battery voltage to keep going.
In my case, (24v bank) the voltage could be as high as 28v after the initial charge from the generator and I would want the solar panels to continue charging the final (say) 20%.
The LG panels have a Vmpp of 33.2 volts which is too close to the battery voltage for the MPPT to start (28v + 5v = 33v)
So, if I'm to use 2 panels, they will HAVE to be is series to get a total Vmpp of 66.4 volts (and thankfully within the operating voltage of the Victron MPPT)

yes, you have mentioned it but I thought we should be OK as I was only considering 24V and not what the batteries may have at the time, indeed close to 28V!

Furthermore, considering that you'd like to take advantage of all the sun even when it's at an angle to the panels, which WILL be for much longer than a proper land installation (and I'm not even thinking about the sun tracking systems used in many parks...) it means that for most of the working day the panels wont be giving out that 33V (me thinks!).
So Serial connection is the only way making more important the proper matching of panels (was thinking maybe 2X280 plus 1X200 across at the forward section of the hardtop, which I wont bother now)

cheers

V.

 

[Hurricane]

yes, you have mentioned it but I thought we should be OK as I was only considering 24V and not what the batteries may have at the time, indeed close to 28V!

Furthermore, considering that you'd like to take advantage of all the sun even when it's at an angle to the panels, which WILL be for much longer than a proper land installation (and I'm not even thinking about the sun tracking systems used in many parks...) it means that for most of the working day the panels wont be giving out that 33V (me thinks!).
So Serial connection is the only way making more important the proper matching of panels (was thinking maybe 2X280 plus 1X200 across at the forward section of the hardtop, which I wont bother now)

cheers

V.

Bit of rethinking going on here.

I had an email from RickP - some will remember him posting on these forums many years ago.
He agreed with most of my findings - i.e. don't use stick on or semi flexible etc
He has some good experience with BenQ panels.
See here
http://midsummerenergy.co.uk/buy/large-solar-panels/benq-auo-333W-mono-solar-panel
At first reading, this would be a good alternative to the LG panels.
Rick pointed out that the voltage is much higher on these panels so I could look at wiring in parallel to reduce any shading issues.
However, considering where I am intending installing them, it might make more sense to wire in series and use the extra voltage to reduce any transmission loss.
He also passed on some performance experience and reckoned that I could get what I want from the system.
He also uses The Victron MPPT controllers.
So, I'm "kind of" thinking that I should buy a product that has some experience of working.
I note that the panels in the link above are also waterproofed properly for marine use.

 

[vas]

Bit of rethinking going on here.

I had an email from RickP - some will remember him posting on these forums many years ago.
He agreed with most of my findings - i.e. don't use stick on or semi flexible etc
He has some good experience with BenQ panels.
See here
http://midsummerenergy.co.uk/buy/large-solar-panels/benq-auo-333W-mono-solar-panel
At first reading, this would be a good alternative to the LG panels.
Rick pointed out that the voltage is much higher on these panels so I could look at wiring in parallel to reduce any shading issues.
However, considering where I am intending installing them, it might make more sense to wire in series and use the extra voltage to reduce any transmission loss.
He also passed on some performance experience and reckoned that I could get what I want from the system.
He also uses The Victron MPPT controllers.
So, I'm "kind of" thinking that I should buy a product that has some experience of working.
I note that the panels in the link above are also waterproofed properly for marine use.

impressive specs on these panels Mike, but also impressive price tag... Doesn't look like anyone imports them down here, so it's a no go for me.
Wondering though if there are other brands that output similar voltages 38 to 54 is a great upstep. Wouldn't bother wiring them in serial though as you then need to go to the 150 series mppt and I think that's even more expensive. Would really like to keep my panels/controller to under 1K euro as the whole h/t is going to set me back almost another 2K.
I'll ask my mate what brand panels he's got on the P45, they are already on their 3rd season and has had no complaints, talking to him today and even with overcast and -2~-6C for the last 4days batteries showed 28V or so yesterday (OK, no consumptions are on and definitely no fridge connected )

V.

 

[vas]

Mike,

just had some more quotes, and did a bit of googling...
Best combination of price performance seems to be these AXITEC AC-300P/156-72S (1965X990X50mm, 3diodes, 36.73Vmpp, 8.18Impp, 15.42%efficiency)
They are a old well established brand (it seems at least) featuring this German engineering moto (but most likely China built...) and 290euro a piece (VAT included), not bad.
http://www.axitecsolar.com/
Performance starts at 97% and drops to 85% at 25yrs, which is rather impressive
My only concern is that they are polycrystaline and they are on the heavy side at 23kg each.

Got to decide next week and order them so that the SS fabricator can get to work...

cheers

V.

 

[rafiki_]

I'm very interested in this Vas. I'm not sure however, how you connect successfully into the batteries, and monitor charge etc. I may have missed some important info on here.

 

[Hurricane]

Mike,

just had some more quotes, and did a bit of googling...
Best combination of price performance seems to be these AXITEC AC-300P/156-72S (1965X990X50mm, 3diodes, 36.73Vmpp, 8.18Impp, 15.42%efficiency)
They are a old well established brand (it seems at least) featuring this German engineering moto (but most likely China built...) and 290euro a piece (VAT included), not bad.
http://www.axitecsolar.com/
Performance starts at 97% and drops to 85% at 25yrs, which is rather impressive
My only concern is that they are polycrystaline and they are on the heavy side at 23kg each.

Got to decide next week and order them so that the SS fabricator can get to work...

cheers

V.

I'm having second thoughts about semi flexibles.
I saw some at the London Boat Show last week and it has changed my mind about them.
They looked very robust - "walk ons"
I would need 4 of them but I can still get 600 watts in the space.
I know that they would get hotter not having the airflow underneath.
But the whole installation would then look like it was supposed to be there.
Also, no glass (rigids are made from glass) - and no cleaning underneath.
These semi flexible ones are stuck down - fit and forget were the words used!!
I must admit that I'm very tempted.
They are polycrystaline - each panel is, effectively, wired in two strings with diodes across the strings.
The voltage is lower - so it would have to be 4 in series.
I will make the decision at the end of the month when I'm out on the boat.
At the moment, it looks like semi flexible for me.

 

[Hurricane]

I'm very interested in this Vas. I'm not sure however, how you connect successfully into the batteries, and monitor charge etc. I may have missed some important info on here.

I believe it is fairly straight forward.
Just buy an MPPT solar controller, connect the solar panels to the MPPT and the batteries across the output of the MPPT.
There probably needs to be some fuses and isolators in there somewhere.
The Victron MPPT controller at just over £200 has a bluetooth addon so that you can monitor the solar panel performance using a mobile phone.

 

[vas]

I'm having second thoughts about semi flexibles.
I saw some at the London Boat Show last week and it has changed my mind about them.
They looked very robust - "walk ons"
I would need 4 of them but I can still get 600 watts in the space.
I know that they would get hotter not having the airflow underneath.
But the whole installation would then look like it was supposed to be there.
Also, no glass (rigids are made from glass) - and no cleaning underneath.
These semi flexible ones are stuck down - fit and forget were the words used!!
I must admit that I'm very tempted.
They are polycrystaline - each panel is, effectively, wired in two strings with diodes across the strings.
The voltage is lower - so it would have to be 4 in series.
I will make the decision at the end of the month when I'm out on the boat.
At the moment, it looks like semi flexible for me.

Yes, in your boots I'd do the same if I could find something decent. Flex and semiflex reputation is nothing to write home about (or rather was and that's an issue as it will take time to improve ppl views as things improve)

Mike, did you try altering temps on the victron XL file to see how it affects current and Amps, rather impressive! I did all my calcs with max temp 70C which I think is closer to what you'll measure midday. Redid them with 60C and was a massive improvement, some panels that needed to be in serial, can now be done in parallel. Although I'll probably order the AXITECs which are OK in parallel no matter what temp

I believe it is fairly straight forward.
Just buy an MPPT solar controller, connect the solar panels to the MPPT and the batteries across the output of the MPPT.
There probably needs to be some fuses and isolators in there somewhere.
The Victron MPPT controller at just over £200 has a bluetooth addon so that you can monitor the solar panel performance using a mobile phone.

+1
Paul, it's fairly straight forward and I believe that with the pattern of use I'll be able to keep off-grid with one 80lt fridge and all BMS, AIS and alarms running throughout the year without problems. With 6+ onboard, I'll probably need to topup a bit with the genny once a day (when running the watermaker fe)
Things aren't so bright up there but they may still be okay

cheers

V.

 

[rafiki_]

Thanks a Mike and Vas. Will look into the controller.

 

[BartW]

I'm having second thoughts about semi flexibles.
I saw some at the London Boat Show last week and it has changed my mind about them.
They looked very robust - "walk ons"
I would need 4 of them but I can still get 600 watts in the space.
I know that they would get hotter not having the airflow underneath.
But the whole installation would then look like it was supposed to be there.
Also, no glass (rigids are made from glass) - and no cleaning underneath.
These semi flexible ones are stuck down - fit and forget were the words used!!
I must admit that I'm very tempted.
They are polycrystaline - each panel is, effectively, wired in two strings with diodes across the strings.
The voltage is lower - so it would have to be 4 in series.
I will make the decision at the end of the month when I'm out on the boat.
At the moment, it looks like semi flexible for me.

exactly what I have in mind,
if I can organise the right size of flexible panels on top of the lower helm station roof, it lookds a bit like roof windows,
thats what I'm looking for,
I believe that I can place aprox 1000W of panels on that space,

Have been designing with "Solara" panels a year go, but didn't continue with the project as too many other things on hand,
Now there are more suppliers of semi flexible solar panels, I came across another good one about a month ago but unfortunately I forgot to note the make.

good plan !

 

[rafiki_]

exactly what I have in mind,
if I can organise the right size of flexible panels on top of the lower helm station roof, it lookds a bit like roof windows,
thats what I'm looking for,
I believe that I can place aprox 1000W of panels on that space,

Have been designing with "Solara" panels a year go, but didn't continue with the project as too many other things on hand,
Now there are more suppliers of semi flexible solar panels, I came across another good one about a month ago but unfortunately I forgot to note the make.

good plan !

Doesn't this mean another potential water leak path Bart? Unless you already have a gland in the right area?

 

[Hurricane]

exactly what I have in mind,
if I can organise the right size of flexible panels on top of the lower helm station roof, it lookds a bit like roof windows,
thats what I'm looking for,
I believe that I can place aprox 1000W of panels on that space,

Have been designing with "Solara" panels a year go, but didn't continue with the project as too many other things on hand,
Now there are more suppliers of semi flexible solar panels, I came across another good one about a month ago but unfortunately I forgot to note the make.

good plan !

These are the ones that I'm considering.
https://www.photonicuniverse.com/en...th-self-adhesive-backing-made-in-Austria.html
I was impressed with their build quality.

They also make a 250 watt version:-
https://www.photonicuniverse.com/en...per-van-rv-boat-or-yacht-made-in-Austria.html
I could use these but I would like to get more power and I could only get 2 of these in the space.
Whereas I can (hopefully) fit 4 of the ones in the first link.
The smaller ones in the first link also have an adhesive backing.

As you say, if they are carefully placed, they might even look like roof windows!!!

 

[WhiskeyTownRacer]

You may wish to search scuttlebutt/practical sections of the forum, I seem to recall a fairly substantial number of comments as to the longevity, or lack thereof, in relation to flexible panels.

 

[BartW]

They also make a 250 watt version:-
https://www.photonicuniverse.com/en...per-van-rv-boat-or-yacht-made-in-Austria.html
I could use these but I would like to get more power and I could only get 2 of these in the space.
Whereas I can (hopefully) fit 4 of the ones in the first link.
The smaller ones in the first link also have an adhesive backing.

As you say, if they are carefully placed, they might even look like roof windows!!!

the available space / rooftop on BA is 3,8m wide and 2.1m long, so I could fit 3 panels of the model above,
would have liked 4, but that doesnt fit.
with 3 panels it looks more elegant / better I think,
the project seems very feaseable !

 

[BartW]

Doesn't this mean another potential water leak path Bart? Unless you already have a gland in the right area?

I don't worry about 1 or 2 more cable glands P, if properly installed, and easy acces for inspection or repair...

the main source of leaks on BA is the old plywood deck with worn teak on top, which isn't water tight anymore,
and difficult / impossible to find the route of the water / impossible to repair.

new deck surface and new teak is planned for next winter !

 

[rafiki_]

I don't worry about 1 or 2 more cable glands P, if properly installed, and easy acces for inspection or repair...

the main source of leaks on BA is the old plywood deck with worn teak on top, which isn't water tight anymore,
and difficult / impossible to find the route of the water / impossible to repair.

new deck surface and new teak is planned for next winter !

��

 

[Hurricane]

You may wish to search scuttlebutt/practical sections of the forum, I seem to recall a fairly substantial number of comments as to the longevity, or lack thereof, in relation to flexible panels.

Yep - been there - thats why I had ruled the semi flexible ones out - see my earlier posts in this thread.
But after going to LIBS, I was impressed with the build quality of the ones I linked to above.
They do look very different to most of the other semi flexible panels,
The sales people convinced me that these panels are strong enough and don't suffer like the ones I've read on scuttlebutt.
They also seemed surprised that there were so many disappointments with the semi flexible panels.
Maybe the ones on scuttlebutt are different - these are a little more expensive that the cheapest.

I'm probably going to make a big mistake here but, as I say, I'm very tempted.
Maybe someone has to be the guinea pig!!

Thanks, though, for posting and pointing out the possible problems.

 

[BartW]

Maybe someone has to be the guinea pig!!

I'll join that club,
even if the panels appear not good / better available after a few seasons
at these prices not really a big deal,
I just repace them with new and better.

 

[vas]

You may wish to search scuttlebutt/practical sections of the forum, I seem to recall a fairly substantial number of comments as to the longevity, or lack thereof, in relation to flexible panels.

Not a regular there and haven't got time to go searching for threads, do you happen to remember if the main complains were on output/performance or physical breaking/falling apart?
I'm asking as in both cases of Hurricane and BartW panels wont be stepped on, so in theory no mechanical forces will be exerted upon them.
I'd expect to have serious performance issues as the areas chosen on yachts are most of the time under some form of shadow so they may well not produce much juice anyway...

cheers

V.

 

[WhiskeyTownRacer]

Not a regular there and haven't got time to go searching for threads, do you happen to remember if the main complains were on output/performance or physical breaking/falling apart?
I'm asking as in both cases of Hurricane and BartW panels wont be stepped on, so in theory no mechanical forces will be exerted upon them.
I'd expect to have serious performance issues as the areas chosen on yachts are most of the time under some form of shadow so they may well not produce much juice anyway...

cheers

V.

I know I've read of physical failures recently, have just done some brief searching and failed to turn up much though. It's possible it was on the cruisers forum, but I genuinely thought it was on YBW, my memory is perhaps not what it used to be.

Output loss via shading is something that any boating application is likely to suffer from I guess, but plenty of people use them successfully despite the inevitable losses.