Solar cells on amas

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Christian
Posts: 182
Joined: Mon 13 Nov 06, 21:55
Your Country: Sweden, Nacka

Solar cells on amas

Post by Christian »

Seen a number of photos of boats with solar cells on amas. How have you done the wiring? In to the beam? It has to work both folded and sailing. And how to get from beam to central hull? Photos and ideas would be appreciated.
/ Christian
Steve B.
Posts: 235
Joined: Thu 02 Nov 06, 1:58
Your Country: USA, Whidbey Island WA

Solar Cells on Amas

Post by Steve B. »

I installed a couple of 100 watt panels on the amas about 8 years ago on our DF 1000. I also have three 120 watt flexible panels on an aft arch.
I put the wiring in a small diameter pvc tube along the upper inside of each ama supported with zip ties and short ss screws.
It's interesting having to work through the aft bulkhead in the forward locker, but it's doable.

At the aft hinges, I drilled holes just big enough for the wires at a spot where they would not ever get caught when the boat is folded. I left enough slack in the wires so they would never be pulled tight when folded or unfolded.

The amas were drilled through the bottom via the small hinge cover.
Wiring was fed through flexible chafe covering and led out a hole in the inner end of the amas. It's been a long time since I did this, but on the inside of the boat I disassembled whatever it took to route the wires to the engine room where I installed a good sized terninal strip for wiring to my MPPT controller.

Last year, I discovered that the two Aurinco 100 watt, WALKABLE flexible panels on the amas had died. Company is out of business and so is my warranty. I replaced them with a couple of 120 watt NON WALKABLE panels from ebay. So far, so good. It's the only NO STEP place on the boat.

One more thing. When I replaced the ama panels, I removed the D ring which attaches the folder line and installed the new panels up very close to the forward hatch. This gives us more stepping area for boarding the boat.
The wiring remains the same. The folder line is installed through a hole I drilled near the drain hole in the center of the ama. The glass is strong enough for folding the boat.

As you may have guessed by the number of solar panels we have, our boat is equipped for cruising. We have an electric head, an ElectroScan sewage system, radar, chartplotter, Spectra watermaker etc.
When we are anchored for a long time and need hot water, we use the inverter to heat it. Lithium Phosphate battery bank is full every day in the summertime. We never use shorepower.
Christian
Posts: 182
Joined: Mon 13 Nov 06, 21:55
Your Country: Sweden, Nacka

Solar cells on amas

Post by Christian »

Hi Steve
Sound like you have figured out almost all I want to know.

When using panels of different brands and sizes – how to connect them to a MPPT controller?
All in – in parallel? Just a terminal strip for 12v battery and connect them into one wire that goes into the MPPT in one place? I do not need to get a MPPT with separate input for each panel?

Do I need to add diodes to avoid problems when just some panels are in the sun? The idea of having one panel on each ama is to have at least one of them in the sun all the time.

What was the reason for not feed the wires inside ama? Risk of interference with swingwing ropes and blocks?

Have been crawling around below the cockpit doing the wiring for my VHF, there are many interesting spaces to be discovered.

/ Christian
Steve B.
Posts: 235
Joined: Thu 02 Nov 06, 1:58
Your Country: USA, Whidbey Island WA

Solar Cells on Amas

Post by Steve B. »

I have two different brands of panels, although they are all semi flexible 120 watts each. 3 on the arch (might add one more) and one on each ama.
I have them all wired in parallel, no diodes and fed to a BlueSky 2512 iX MPPT controller, then to the 200 aH Lithium Phosphate battery bank.
On a sunny day in the summer and if batteries are down much, I can max out the controller at 25 amps. It has a protection circuit in it which keeps it from over current.
The reason I have so much power?
Watermaker, inverter for hot water, wife likes to sew, we watch movies, etc.
Life is good when we're on the boat !
Mika Harju
Posts: 218
Joined: Thu 02 Nov 06, 13:19
Your Country: Finland, Turku

Re: Solar Cells on Amas

Post by Mika Harju »

Hi Steve
Referring your LiFePO4 batteries how have you prevented to overcharge those when you have several ways to charging? Solar cells, inboard engine alternator, shore power charger, hydro generator, wind generator etc...

Few questions:
1-What kind of battery management unit(s) do you have?
2-How is it connected?
3-What kind of user interface do you have?

My plan is to replace my AGM batteries with LiFePO4 technology but stuck to find out the right way to prevent overcharging and keep the system simple. DIY solutions to solder manually separate management units to each battery cell looks not reliable nor safe solution for me.

My system has 3x100W solar power, Volvo inboard engine and shore power charger connected to 140Ah AGM battery and the plan is to buy about 150-200Ah battery bank.
Mika Harju
DF1000 Racing #8
Steve B.
Posts: 235
Joined: Thu 02 Nov 06, 1:58
Your Country: USA, Whidbey Island WA

LifePo4 Charging

Post by Steve B. »

I have an external voltage regulator on the alternator which I keep set to 13.6.
Most of my charging comes from solar which is regulated by the BlueSky 2512 iX MPPT controller.
I have a 20 amp shore power charger which I have not used in years.
I have a 200 aH lithium phosphate bank and no separate engine start bank.
The lithium bank was taken down to 80% discharge just to see if the engine would start. It did, and sounded like the bank was fully charged !
I have a 123BMS which is no longer available, but it's really just for insurance.
I have not installed any HV or LV disconnects, and really see no need for them.
All this was installed in 2011 if I remember correctly.
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