Our first year with lithium

[geem]

The module e

My 200W of Renogy flexible ETFE panels regularly go to 208W on a clear day so perhaps something wrong with yours given your better location.

Efficiency of the 200w panels is quoted as 16.7%. The 50w panels I have are only 14%. I chose the 50w panels for their convenience of being able to store them when not in use. They are mounted on a piece of canvas so when we fold them, 4 panels take up only the space of one when not in use.
I will look out for some higher Efficiency panels when I get back to the UK. I am also considering bifacial panels to replace my guardrail mounted panels. We should see about 10% improvement in output for the same area of panels. Our current 720w of rail mounted panel should be closer to 900w. As the new panels are more efficient anyway.

 

[Trident]

well, i am afraid they will just say "Victron", which are 3 X the cost of others.

I'm trying to have other ideas.

Are Renogy batteries used much in boats?

Victron in testing are nothing like the best batteries anyway. Well know marine brands like Sterling just rebadge cheap Chinese stuff and give very poor advice. Many companies now have passable drop ins (for want of a better word) but the best two independently tested are Renogy and Battleborn. The latter are not available in the UK easily. Fogstar have good reports so far but are new to the LifePo4 drop in game - their previous reputation with batteries is excellent though.

I've fitted Renogy now to dozens of boats in the last few years with no problems what so ever and after hard daily use for cooking and water heating etc on my own boat I have lost just 0.8% capacity in 4 and a bit years. Certainly a lot of people have the Renogy in boats and RVs etc - they even make a seriously waterproof version now.

I'd say if you choose a Renogy or a Fogstar you'll do well - both are well made, have a well know good BMS and are very good on price - I think Fogstar are slightly cheaper if you buy the big batteries (my own preference is however for several smaller -100ah or 200ah - batteries so that if one dies its not your whole bank or a big chunk of it - I have 7 x 100ah Renogy and should one fail I can disconnect it and carry on with 6 until I get a replacement )

I find it odd that insurers care not a jot about people fitting their own lead acid and often rewiring themselves and yet suddenly seem to care about LifePo4 despite it being safer than LA batteries. Also, as there is no legally recognised qualification for marine electricians what counts as certified installer?

 

[Trident]

The module e
Efficiency of the 200w panels is quoted as 16.7%. The 50w panels I have are only 14%. I chose the 50w panels for their convenience of being able to store them when not in use. They are mounted on a piece of canvas so when we fold them, 4 panels take up only the space of one when not in use.
I will look out for some higher Efficiency panels when I get back to the UK. I am also considering bifacial panels to replace my guardrail mounted panels. We should see about 10% improvement in output for the same area of panels. Our current 720w of rail mounted panel should be closer to 900w. As the new panels are more efficient anyway.

All flexi panels are less efficient - its just the nature of the beast. The new 320 framed I got from Renogy are around 6% better than the flexi and so of course produce more - because of this they are also in the best location for maximum sun so I can't do a like for like per sq ft comparison but if you can use framed then thats the way to go.

Last I looked the Maxeon 4 panels were the highest efficiency available at 23% but the new Renogy are only a fraction behind now and they do the bifacial panels and are a lot less expensive.

US readers may have customer service gripes but the UK set up is great - I had 4 panels shipped (2x2) and the carrier broke one in one of the boxes of two . I called Kai, who is in charge at Renogy UK and they sent out a new box within 48 hours with 2 new panels in and when I asked if he wanted one returned as I'd only lost one he just said have it on us for the inconvenience ...

My wife's birthday tomorrow so we had a cake baking in the electric oven for 80 minutes this afternoon - after a day of making hot water and cooking lunch etc as well as PCs, fridge, freezer, tv etc - and finished baking at around 1730. Only down to 92% battery and when the solar clicked off at sunset I noticed we'd fill up to 100% again even with the sun so low in the sky ... the 2S2P framed panel set up working very well

 

[Sea Change]

The obvious thing is to build your boat as a 24v system. It makes lots of sense with lithium as BMS are rated in amps. When you double the voltage to 24v, you half the amps so you BMS effectively handles twice the power. Your cables sizes to everything become much smaller for the same volt drop. As a consequence, the cost of rewiring the boat is much reduced

I think that depends on what you're powering. If fitting a big inverter etc then definitely 24v has huge advantages. Although it does commit you to buying eight cells. So the basic price of entry is higher.
If you're only powering lights and VHF etc, might as well stick with 12v.

In hindsight I would have better going to 24v. But I was trying to complete the project on a very tight budget, so only bought 4 cells initially. I've since upgraded to a bigger battery, but of course I've already bought my 12v inverter...

 

[Sea Change]

I'm curious, if designing and installing a complete rewire of a boat, is there anything that would be done differently if the system was going to be powered by lithium instead of agm batteries?
ie, can I redo my electrics and then decide at the end if I want to go lithium or not for the power?
I was intending to keep it simple, two new 120ahr agms and an engine battery. But I must admit it's tempting if buying batteries from new to just go Lithium from the start.

If you plan for lithium, you will end up with a very robust and safe system with the best available fuses, highly configurable chargers, and alternator protection. You could then stick lead acid in if you want. But why would you? You can assemble lithium batteries cheaper than you can buy AGMs.

 

[Neeves]

If you are wondering about a Lithium build or planning one you need to read this thread and an earlier one by Geem

My lithium build

Kelpie, now Sea Fever posted a thread on his build, maybe he can provide the link and there have been 3 other builds described on PBO (but I forget who).

There will still be missing information - the fact you need 3-4 MPPT controllers was never really undermined previously (and they are neither cheap nor small - so you need deeper pockets and more space). There is a focus on BMS, when building a battery bank, but little detail on where to source one.

Jonathan

 

[Seven Spades]

We installed 600aH at 24V Victron batteries and our experience reflects the comments of others. We only have 380W of solar and when we took the boat to the med we ran the generator for only one hour the whole season.

However the cost to us was considerable. We had to replace our alternator and we installed 2 X 160aH Rolls AGM batteries. These are charged by the Lithiums using DC-DC chargers and are there just to power our 24V Desolator. The Desolator apparently does not like lithiums so now it only sees the lead acid batteries.

We were a bit unlucky as we replaced our cooker with a GN Espace at the same time only for them to bring out an induction version about 8 months later. We have an all Victron system and I am sure paid a heavy price for doing so but... everything talks to everything and the insurance company is very happy with it.

For us the biggest saving is the generator. It used to take about 14 hours on our generator to get the lead acids to float. Now we can fully charge in under 3 hours from 20-100% but in practice we don't need to run the generator most of the time.

 

[geem]

If you are wondering about a Lithium build or planning one you need to read this thread and an earlier one by Geem

My lithium build

Kelpie, now Sea Fever posted a thread on his build, maybe he can provide the link and there have been 3 other builds described on PBO (but I forget who).

There will still be missing information - the fact you need 3-4 MPPT controllers was never really undermined previously (and they are neither cheap nor small - so you need deeper pockets and more space). There is a focus on BMS, when building a battery bank, but little detail on where to source one.

Jonathan

If you want a good bms it's hard to find anything better than JK for the money. They will handle 200A and give you up to 2A of active balancing. Cost around £100. EBay and several lithium battery companies in the UK sell them.
My friend with a cat has 900W of solar and a single Victron BMS. He runs his watermaker, large fridge and freezer but no electric cooking. Alternator charging off both engines with an expensive REC BMS and Wakespeed regulators. Lots of different ways to design your system.

 

[lustyd]

The module e
Efficiency of the 200w panels is quoted as 16.7%. The 50w panels I have are only 14%. I chose the 50w panels for their convenience of being able to store them when not in use. They are mounted on a piece of canvas so when we fold them, 4 panels take up only the space of one when not in use.
I will look out for some higher Efficiency panels when I get back to the UK. I am also considering bifacial panels to replace my guardrail mounted panels. We should see about 10% improvement in output for the same area of panels. Our current 720w of rail mounted panel should be closer to 900w. As the new panels are more efficient anyway.

With the numbers you quoted it sounded more like a problem than efficiency. Renogy flexible panels will deliver slightly more than 100% of their rated power in good sunlight and you said you weren’t close to that so worth doing some investigation. If they’re on canvas and moveable maybe something has been damaged?

 

[Neeves]

We installed 600aH at 24V Victron batteries and our experience reflects the comments of others. We only have 380W of solar and when we took the boat to the med we ran the generator for only one hour the whole season.

However the cost to us was considerable. We had to replace our alternator and we installed 2 X 160aH Rolls AGM batteries. These are charged by the Lithiums using DC-DC chargers and are there just to power our 24V Desolator. The Desolator apparently does not like lithiums so now it only sees the lead acid batteries.

We were a bit unlucky as we replaced our cooker with a GN Espace at the same time only for them to bring out an induction version about 8 months later. We have an all Victron system and I am sure paid a heavy price for doing so but... everything talks to everything and the insurance company is very happy with it.

For us the biggest saving is the generator. It used to take about 14 hours on our generator to get the lead acids to float. Now we can fully charge in under 3 hours from 20-100% but in practice we don't need to run the generator most of the time.

Apologies Seven Spades, you were one of the members who had posted their Lithium experience but whose name I had forgotten. Nothing personal - I'm terrible with names.

Jonathan

 

[vas]

@lustyd Med experience with flexible panels is that they heat up, underperform and soon after fall apart.
I guess geem at the caribbean is facing the same issues.

Where are you based, as I'd expect UK waters to get most out of flex panels than hotter climates.

 

[Sea Change]

There will still be missing information - the fact you need 3-4 MPPT controllers was never really undermined previously (and they are neither cheap nor small - so you need deeper pockets and more space). There is a focus on BMS, when building a battery bank, but little detail on where to source one.

Jonathan

You don't need 3-4 MPPTs. I happen to have two, but I ended up with a mixture of different solar panel types because I got a deal secondhand, and already had some panels. So the small 12v panels run on one, and the big 30v panels run on the other.
If starting from scratch it's entirely possible to run a single MPPT. However you may find that two smaller ones cost about the same as one larger one. It just depends on your system.

You can buy your BMS from all sorts of places, I've bought two from Home Page - LLT POWER ELECTRONIC and I was perfectly happy with the price, quality, and service.

 

[lustyd]

@lustyd Med experience with flexible panels is that they heat up, underperform and soon after fall apart.
I guess geem at the caribbean is facing the same issues.

Where are you based, as I'd expect UK waters to get most out of flex panels than hotter climates.

Yes that's quite common with older panels. Modern ETFE ones I've not heard of any issues.

 

[Trident]

I think that depends on what you're powering. If fitting a big inverter etc then definitely 24v has huge advantages. Although it does commit you to buying eight cells. So the basic price of entry is higher.
If you're only powering lights and VHF etc, might as well stick with 12v.

In hindsight I would have better going to 24v. But I was trying to complete the project on a very tight budget, so only bought 4 cells initially. I've since upgraded to a bigger battery, but of course I've already bought my 12v inverter...

In hindsight I too would have gone 24v with a step down for the cheaper 12v pumps and instruments - the 120mm cable to my inverter is now £1200 a reel - halving the size on that and on fuses etc would have saved a lot of money and weight and heat.

Since the next boat will undoubtedly be a hybrid with electric motors as well as diesel then 48v would allow for a sensible engine circuit and a nice meaty 48v 5kw inverter - in fact IIRC Victron have a 48v 15kw inverter which would allow my wife to indulge in everything she could ever imagine all at once

 

[GHA]

Firmly at the DIY end, 4 x 300Ah Catl cells delivered 450UKP, fuse €100. No BMS but very careful monitoring, still very closely balanced after 16 months.
Charged by 300W solar, 2 x victron smartsolar mppt & smartshunt does a great job at stopping charging just before 100%, cost same for any battery bank so irrelevant.

 

[Trident]

@lustyd Med experience with flexible panels is that they heat up, underperform and soon after fall apart.
I guess geem at the caribbean is facing the same issues.

Where are you based, as I'd expect UK waters to get most out of flex panels than hotter climates.

Older generation flexi panels have been problematic but certainly the Renogy in the last few years have had no problems with delimitation etc. All flexi panels would prefer to sit on a layer of that nice polycarbonate roofing with a gap in the middle so they don't get so hot but mine are just straight on the deck due to curves and laziness and are showing no signs of any degradation over 4 years now.

I also just tested some I put on a boat that the owner abandoned to flee the police (long story) and the marina are now breaking up after 18 months without payment . 6 panels, all unconnected as the owner took the batteries and controllers off to eBay before he did a runner - all uncovered for all that time with nowhere to put the power (but with more modern technology this isn't the issue it was) and they're still running 24v and full output in the sun .

 

[vas]

@Trident, are you based somewhere that sun shines, if not, no offence, I would not buy something based on your experience...
When I started rebuilding my boat, ppl recommended v.highly Owtrol (?) for treating iroko. Promptly bought a 4-5lt can and still have more than half of it as it only lasted a few months down here - not even a full May to Oct.
Even for the two framed 300W 1X2m panels I have on the hardtop I can see a drop in performance after 5-6yrs

 

[lustyd]

@Trident, are you based somewhere that sun shines, if not, no offence, I would not buy something based on your experience...
When I started rebuilding my boat, ppl recommended v.highly Owtrol (?) for treating iroko. Promptly bought a 4-5lt can and still have more than half of it as it only lasted a few months down here - not even a full May to Oct.
Even for the two framed 300W 1X2m panels I have on the hardtop I can see a drop in performance after 5-6yrs

Unless you’re talking about the same panels we are then same applies. Both of us said ETFE and excluded older panels with problems.

 

[vas]

Unless you’re talking about the same panels we are then same applies. Both of us said ETFE and excluded older panels with problems.

apologies, my 2 300W are solid ali framed glasswhatever covered normal panels, not flexible.
thinking about adding a couple of oblong flex ones hence me asking.

 

[geem]

With the numbers you quoted it sounded more like a problem than efficiency. Renogy flexible panels will deliver slightly more than 100% of their rated power in good sunlight and you said you weren’t close to that so worth doing some investigation. If they’re on canvas and moveable maybe something has been damaged?

They have had the same low efficiency since the day I installed them. There is no damage. I just don't think they are any good. 14% module efficiency is very poor these days. The only saving grace is they were very cheap. I do wonder if they lose some efficiency being mounted on canvas and then on the suncover. The guardrail mounted framed panels have good airflow to their underside. They are very well cooled. This isn't the same for the .Renogy floppy panels. Their underside is effectively insulated. I will check the surface temperature of the panels later and compare and report back