Solar / battery refit First 38

[Bob Morane]

Hello everyone.

As I am making the leap from week-end sailing to living aboard for the next 5-10 years, I'm contemplating a full refit of the solar and batteries on my Beneteau First 38.

It currently has 220w of solar panels and these are 18 years old and producing nowhere near as they should anymore.
In the same fashion, the house battery bank is composed of 2 × 100 AH 12v AGM batteries, both from 2016 and starting to get very tired.
Starter battery is the usual LA starter.

The boat has a fridge, a fan per cabin (3), an autopilot and a VHF. Cooking is gas, no icemaker or freezer.
Plotting will be done on tablet and phone, no radar, very little integrated electronics overall apart from the sounder.
I plan to change most lights to LED and install a small watermaker. I will also have a 12v diving compressor that I will charge during the day.

I have roughly budgeted that I would need 130-180ah per 24h underway and ~80-120ah per 24h on anchor.
I want to be able to live on anchor for extended periods without starting the engine or using a generator.

I have done a fair bit of reading and still feel very lost, especially when going into details about components so I will just say what I want to do and feel free to jump in if that sounds stupid, inefficient or if I'm off by a mile.
Also feel free to suggest components that you would recommend.

4 x 100w arch mounted panels in parallel
- Plenty of choice here, would appreciate recommendations

into a 40amp MPPT charge controller
- Renogy Rover MPPT 100v 40A or similar

into 3 × 100ah LFP batteries in parallel.
- To be determined

Now questions :

1) Does having 4 panels in parallel going into a charge controller make sense ?

2) Each of the LiFePo battery will have an individual integrated bms. Is there a need to have another component to manage the 3 of them in parallel ? It seems to me that management is crucial in series but not in parallel, just double checking.

3) Does anyone have a good LFP battery supplier shipping in Europe ? GLV seems to be a good one but they do not make battery "packs" ready to go. I am not that keen to pay the insane mark-ups like victron either. I would be grateful if someone has some pointers on how to get good bangs for your bucks here, including DIY if necessary.

4) Is there any upside to having 3 × 100ah batteries vs a single 300ah battery ?

5) How to check if your alternator is adequate for your battery bank ? Is that as simple as checking that the amperage of your alternator isn't over 3 times the charge limit of each individual battery ?

6) Where would I need fuses/breakers ? Between the charge controller and the batteries, between the panels and the charge controller ? Or both ?

7) Is there any benefit changing the starter battery ? The house and starter circuits are independent so I'm assuming not ?

Although I understand the basics of electricity, I am still very novice when practicals are involved. Especially when a combination of economics, efficiency and safety is to be considered and balanced.

Cheers for your help and have a good week-end.

[Bob Morane]

Sorry, I just realised the answer to question n°6 was available in a thread on the first page.
Fuses within 7" of the batteries as it is the unlimited power source.

[Uncle Bob]

Originally Posted by Bob Morane

Sorry, I just realised the answer to question n°6 was available in a thread on the first page.
Fuses within 7" of the batteries as it is the unlimited power source.

There are some here that would have you install a fuse for each panel, a circuit breaker prior to the controller, a circuit breaker after the controller and then the fuse prior to the battery.
Follow the manufacturer's advice, I tend to believe that their advice is likely to meet all the requirements.!

[Bob Morane]

Originally Posted by Uncle Bob

There are some here that would have you install a fuse for each panel, a circuit breaker prior to the controller, a circuit breaker after the controller and then the fuse prior to the battery.
Follow the manufacturer's advice, I tend to believe that their advice is likely to meet all the requirements.!

Sorry, this would be my first time putting such a system together as I have been relying on the existing system on my boat since I bought it in 2018.
Therefore this might seem like a stupid question but when assembling a system with batteries, charger and panels from different manufacturers, do they all have requirements or is that coming from a component in particular like the controller ?

[Uncle Bob]

Originally Posted by Bob Morane

Sorry, this would be my first time putting such a system together as I have been relying on the existing system on my boat since I bought it in 2018.
Therefore this might seem like a stupid question but when assembling a system with batteries, charger and panels from different manufacturers, do they all have requirements or is that coming from a component in particular like the controller ?

Hi having had a discussion with low energy developments in Melbourne recently regarding how to improve the solar harvest on my boat in Sydney, I came away with the info that solar panels in parallel should be the same , to one controller or one controller per panel for max harvest, MPPT of course, controller slightly higher capacity that expected input, and installed to manufacturers requirements.
I have a little upgrading ahead of me.

[Bob Morane]

Originally Posted by Uncle Bob

Hi having had a discussion with low energy developments in Melbourne recently regarding how to improve the solar harvest on my boat in Sydney, I came away with the info that solar panels in parallel should be the same , to one controller or one controller per panel for max harvest, MPPT of course, controller slightly higher capacity that expected input, and installed to manufacturers requirements.
I have a little upgrading ahead of me.

Cheers for the info.
So 4 x 100w of same panels in parallel, 40A MPPT controller should be alright for around 6A per panel and install fuses and breakers per the controller requirements of the manufacturer.

[Uncle Bob]

Originally Posted by Bob Morane

Cheers for the info.
So 4 x 100w of same panels in parallel, 40A MPPT controller should be alright for around 6A per panel and install fuses and breakers per the controller requirements of the manufacturer.

Hey, that's what I would do, but I am sure others would disagree.

[Bob Morane]

Does anyone have any pointers on good value LFP batteries that can be shipped to Europe ?

If I was in the US, I would get some SOK (out of stock) or AmpereTime (they don't deliver in France).

I've been looking at the Winston 300ah 12v kit at GWL, but I'm a bit scared of the DIY aspect and screwing it up.

Then there's the AliExpress/Amazon/Ebay cheap ones where it seems like gambling.

I've started reading the DIYsolar forum and various sources.
Still feeling a bit lost and would love a bit of guidance if anyone has a good feedback on decently priced batteries.

[more]

Originally Posted by Bob Morane

Hello everyone.

As I am making the leap from week-end sailing to living aboard for the next 5-10 years, I'm contemplating a full refit of the solar and batteries on my Beneteau First 38.

It currently has 220w of solar panels and these are 18 years old and producing nowhere near as they should anymore.
In the same fashion, the house battery bank is composed of 2 × 100 AH 12v AGM batteries, both from 2016 and starting to get very tired.
Starter battery is the usual LA starter.

The boat has a fridge, a fan per cabin (3), an autopilot and a VHF. Cooking is gas, no icemaker or freezer.
Plotting will be done on tablet and phone, no radar, very little integrated electronics overall apart from the sounder.
I plan to change most lights to LED and install a small watermaker. I will also have a 12v diving compressor that I will charge during the day.

I have roughly budgeted that I would need 130-180ah per 24h underway and ~80-120ah per 24h on anchor.
I want to be able to live on anchor for extended periods without starting the engine or using a generator.



4 x 100w arch mounted panels in parallel
- Plenty of choice here, would appreciate recommendations

into a 40amp MPPT charge controller
- Renogy Rover MPPT 100v 40A or similar

into 3 × 100ah LFP batteries in parallel.
- To be determined

Now questions :

1) Does having 4 panels in parallel going into a charge controller make sense ?

2) Each of the LiFePo battery will have an individual integrated bms. Is there a need to have another component to manage the 3 of them in parallel ? It seems to me that management is crucial in series but not in parallel, just double checking.

3) Does anyone have a good LFP battery supplier shipping in Europe ? GLV seems to be a good one but they do not make battery "packs" ready to go. I am not that keen to pay the insane mark-ups like victron either. I would be grateful if someone has some pointers on how to get good bangs for your bucks here, including DIY if necessary.

4) Is there any upside to having 3 × 100ah batteries vs a single 300ah battery ?

5) How to check if your alternator is adequate for your battery bank ? Is that as simple as checking that the amperage of your alternator isn't over 3 times the charge limit of each individual battery ?

6) Where would I need fuses/breakers ? Between the charge controller and the batteries, between the panels and the charge controller ? Or both ?

7) Is there any benefit changing the starter battery ? The house and starter circuits are independent so I'm assuming not ?

Although I understand the basics of electricity, I am still very novice when practicals are involved. Especially when a combination of economics, efficiency and safety is to be considered and balanced.

Cheers for your help and have a good week-end.

Lot question.
first biger is 4x100w solar panel from new halfcut 400 w with technology use in manufacture PERC cell or black contact or HIT
for example 169 cm x 100 cm 400W +5%
https://sunpower.maxeon.com/int/site...ble_536423.pdf
for this up solar panell you need tracer 4210AN budget
https://www.aliexpress.com/item/3262...48e72e0e7WbaQW

or tracer4215b

100 W solar panel is manufacture from the lowest grade cell.
for you consumption, you need min 300-430 W.
you dont need BMS for lifepo4 and if you bulid you need only 1 bms Dally waterproff.
if bulid you make 3x100 ah paralel and make 4s serial conection.

is very good have fuse in batery and also solar dual fuse from solar panel to solar controler this also use like switch on/off for solar panel

batery monitor is good have also good is cell monitor.