Originally Posted by Jbradley15
Hey all, I am just finishing purchasing
a Wauquiez Amphitrite 43 and since the batteries are trashed for the power bank (and the engine power) I have found myself in a position that I am able to design a new battery system and will be using a combination of alternator power and solar power to maintain and charge these battery banks.
Heres what I am thinking:
I would like to use two to four Renogy Deep Cycle AGM Battery 12 Volt 200Ah for the main battery bank and two Optima Batteries 8004-003 34/78 RedTop Starting Battery for the engine power.
side note: I will be having children
sleeping above the battery banks so FLA is out of the question for me.
Understandable about not wanting to sleep above batteries! I've heard that CO alarms are also sensitive to LA battery gassing. Installing one very close to the batteries might provide an additional level of safety
. Not sure whether the RedTops still live up to their name.
I'm a little shaky on the voltage regulators etc and I will be doing more research on how to charge these batteries correctly, I read AGM and SLA can have serious issues if they are overcharged and would like to prevent that while using a large brushless alternator such as this one (https://www.discountstarterandaltern...single-2spool/) when the solar power doesn't keep up or when I need to top the batteries (wikipedia said once every three months will preserve battery life on AGM batteries, please tell me if thats wrong).
AGM is indeed rather sensitive to overcharging (same for Gel), far more than FLA. SLA is somewhat in between. Overcharging occurs when the chargers stay too long in the absorption phase. Many chargers advertise their special voltages, but what you actually need is smart logic that transitions to the float phase at the right moment.
The Victron SmartSolar MPPT
chargers are really nice in this regard as they offer a lot of programming freedom (far more than just voltages, also absorption time limits, tail current
etc.), can talk to each other over Bluetooth such that they synchronize their charge phase and can talk to a battery voltage sensor
such that they base their charge phase on the actual battery voltage and not the distorted voltage at their own output. The VE.Direct protocol is open-source so you can easily interface them with a RPi or so if you desire so. They are a bit pricey but you also get something in return.
What kills LA batteries is the sulfation that occurs when they are not fully charged. This occurs very rapidly. Topping up every three months is the very least
one should do. One ought to fully charge LA batteries at least once a day.
I am okay with arduino and raspberry pie and am considering using these to create a voltage and amperage regulator, I still need to learn more about what exactly these batteries need to build something like this. I might just buy a regulator depending on price and system fit.
. In case you haven't yet stumbled on it, this open-source project might provide some inspiration: https://arduinoalternatorregulator.blogspot.com/
. Now and then second-hand Balmar
regulators pop up for very reasonable prices.
So I'm a bit shaky on all of this but mostly the solar arrays and I have a pretty specific set of perameters I will be needing to deal with. Since everything on a sailboat is a compromise I will just list the "perfect" solar panel syetem and start compromising from there. [...]
It is indeed always a compromise. Some people prefer flexible panels that they carry around the boat
. I've the impression those panels spend quite some time inside the boat where they generate little power. I prefer hard panels that are installed such that they can stay outside all the time as I don't like to adjust my day to carrying solar panels
We studied our boat carefully to see where there is space for panels and then selected suitable panels. We felt that a few hundred Watt-peak (Wp) delivered a significant contribution. A quick picture search on your boat model (nice yacht BTW!) turns up a few locations for hard panels, such on a hard top, on a davits
or on the rigid stern railing. It is a sailboat so do take into account where you'll have to be while handling the sails! The hard top might not be that preferable in that regard.
Residential solar panels
have shown to do perfectly fine in the marine environment
as long as they are supported sufficiently. They also tend to be rather affordable. They are large but they also generate a lot of power if they are unshaded. Smaller panels can be found in RV shops. For the technology you'll want monocrystalline as these generate considerably more power for the same surface area (but generally are also more expensive for the same power). We didn't bother with 'marine grade' as it seems to correlate mostly to the price tag and not to any actual difference in materials, workmanship or design.
I have found out that partially shading a solar panel can cause MASSIVE amperage drops whe even a small area of the panel has been shaded. Im figuring that this is caused by the way the panels are wired (PLEASE CORRECT ME IF I'M WRONG). [...]
Indeed! Excellent observation. Many panels try to address this issue using several strings that are put in series with a bypass diode or put in parallel. Shingled panels come to mind. In the end shading is something we have to live with, I'm afraid.
In a feeble attempt to save money and design the panels with alternative wiring (shading problem fix hopefully) I am planning on building the panels myself. I will keep you guys updated on how this project goes.
While it is your choice what you spend your time on, with such a beautiful yacht I'm afraid I would prefer sailing over building solar panels. I doubt you'll be saving any money and I also doubt they will perform better, yet feel free to prove me wrong. Building something that holds its own in the marine environment
is achievable but is not easy. Salt water
is a bitch. BTW if you haven't yet be sure to check out the marinehowto site: https://marinehowto.com/
. He wrote one of the landmark articles about lithium
batteries on boats.