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Solar panels

Posted: September 5th, 2020, 9:14 am
by tonyiiiafl
I am seriously thinking of solar panels on the roof of my 390CPMY to help keep batteries charged during the day while at a mooring or anchored. I have a 3 bank charger that charges all batteries, Start, House and Genset. How did you all wire them in? Did it hurt the on board charger? Pics?

Thank you again!

Re: Solar panels

Posted: September 5th, 2020, 3:03 pm
by g36
What are you running that your house bank can't keep up with? Or how long between charges or engine running? Would resizing your house bank take care of your needs cheaper or more easily,?

Re: Solar panels

Posted: September 5th, 2020, 4:24 pm
by tonyiiiafl
Well.....I have 2 golf cart batteries set up as a 12, parallel. We are doing more moorings than slips lately. So, We run the NorCold on 12V (old but I think very economical) and also house lights, Vacuflush, and I wish to get a 12V LED TV. Aside from that nothing much. Batteries do well, I will go to bed at about 9 (I am getting old!)and batteries are are charged to 90 to 95% by running the genset for 2.5 hours. This accomplishes getting the water heater going and the batteries charged. In the AM, I am somewhere around 78-82% charged. Again, run genset for 2.5 hours to charge batteries to 90% +/- and hot water, make coffee, cook breakfast etc. I was thinking if I had a couple of solar panels the batteries would trickle charge all day. The only place I could get another bank in would be under the galley floor. I could make a platform, and place 2more GC 6V batteries in there and run a 4/0 cable to connect the two banks together. That would give me a large house bank (approx 900 AH). Thoughts?

Re: Solar panels

Posted: September 5th, 2020, 4:53 pm
by Midnightsun
I wired mine in directly to charge the house bank only. No issues with charging conflicts. Just get a good mppt charge controller for the panels and you are good to go. I am really pleased with the overall performance. Running dual 150w panels for a total of 300w.

Re: Solar panels

Posted: September 5th, 2020, 5:29 pm
by tonyiiiafl
Now, here is a query......How or if does this conflict with the battery charger or does the controller take care of this? I would allow it to just charges the House. Where did you get this set up? And, if I may, rough costs?

Re: Solar panels

Posted: September 5th, 2020, 6:47 pm
by Midnightsun
The controller like your battery charger or alternator are smart enough to know what they should do, no worries. Pretty straight forward, solar palnels to controller, controller to house bank. Prices van vary quite a bit but lets say for $1000 including everything, panels, controller, wiring, connectors you will have something really nice. Can get away at halftone cost but it will be cheap stuff. Do it right the first time or expect to do it again. ;-)

Re: Solar panels

Posted: September 5th, 2020, 7:31 pm
by g36
I am using 6v gc batteries. I have 6 on my 405 I am powering a extra 120v fridge along my satellite TV, some extras and cpap at night. I will run the genset at night to bring charge back up having to have ac to cool boat off. I can go 2 days if needed without charging but generally don't cause of the summer heat.. I think you may be unclear on the amp hours when connecting in series. You will double your voltage so that will be 12vdc but your amps say trojan T105s will remain the same at 225. So with 2 realistically only using 1/2 of their capacity youll be at apx 112 useable amps. Not really alot. So adding 2 more your total bank would be 450 amps usable st 225. It would help if all of your interior lights, anchor light etc are led also. A invertor for tv use will be fine and be much less expensive to buy a 120v TV than 12vdc one and more choices. If your low in 1 day then a larger bank would help and still be cheaper than $1000 apx that was mentioned even 4 more gc batteries is also. Space may be a problem and solar may be your choice. My setup works for me . You may desire something else just thought I would share.

Re: Solar panels

Posted: September 5th, 2020, 8:30 pm
by tonyiiiafl
Totally appreciate the share! I am thinking of expanding the bank to 4 T105’s. Silly thought but with the single 12V starting and the single 12V genset battery, I would assume the charger ProMariner 50A 3 bank charger. So I would assume that the other two GC batteries will be set up in parallel to the original 2, making a big 12V bank. Charger will know what to do as far as charging the bank. Yes, I am also going to look into the solar to help keep the bank charged during the day. today for example, I went from 9:30AM until 5:00PM using the house bank. When I switched on the genset to charge the bank, it was still at 90%.

Re: Solar panels

Posted: September 5th, 2020, 8:31 pm
by tonyiiiafl
tonyiiiafl wrote:Source of the post Totally appreciate the share! I am thinking of expanding the bank to 4 T105’s. Silly thought but with the single 12V starting and the single 12V genset battery, I would assume the charger ProMariner 50A 3 bank charger. So I would assume that the other two GC batteries will be set up in parallel to the original 2, making a big 12V bank. Charger will know what to do as far as charging the bank. Yes, I am also going to look into the solar to help keep the bank charged during the day. today for example, I went from 9:30AM until 5:00PM using the house bank. When I switched on the genset to charge the bank, it was still at 90%.
I have already switched all lighting to LED, made a huge difference. Also!

Re: Solar panels

Posted: September 5th, 2020, 8:32 pm
by tonyiiiafl
tonyiiiafl wrote:Source of the post
tonyiiiafl wrote:Source of the post Totally appreciate the share! I am thinking of expanding the bank to 4 T105’s. Silly thought but with the single 12V starting and the single 12V genset battery, I would assume the charger ProMariner 50A 3 bank charger. So I would assume that the other two GC batteries will be set up in parallel to the original 2, making a big 12V bank. Charger will know what to do as far as charging the bank. Yes, I am also going to look into the solar to help keep the bank charged during the day. today for example, I went from 9:30AM until 5:00PM using the house bank. When I switched on the genset to charge the bank, it was still at 90%.
I have already switched all lighting to LED, made a huge difference. Also!
I have a 2500w/5000 surge inverter already installed, so I can run an extension cord to the inverter for TV.