solar panels

[Cruisingdad]

Originally Posted by justonemoreproject

I have 2 solar panels for a trickle charge but will be adding more instruments and now need to increase the size of my array. Can anyone make some brand recommendations based on personal experience?

Thanks

I have Kyoceras and other cruisers I know use them too without issues. They are well made and dependable. They come (at least mine did) with blocking diodes too.

Hope that helps.

- CD

[erps]

They come (at least mine did) with blocking diodes too.

what do those thingies do?

[sailingdog]

Blocking diodes prevent the panels from draining the batteries at night. If there isn't enough light hitting the panels, they can actually drain electricity...

Originally Posted by erps

what do those thingies do?

[johnnyboats]

i dont know how to calculate the exact amperage of a 48v system, i know its would be beter to use 6v bateries, trojan makes a nice 300+ amp 6v, how much would that drop at 48v, and how much would it add up with 8 bateries in series? as for panels i figure i have room for 4 100+ watters, if there aprox. 50" long i could probably squeeze them onto my hardtop

[camaraderie]

Eight 6 volt 300a/h batteries is the equivilent of ONE 48V battery with 300a/h's. So...you would have 150a/h's at 48V to work with to get to 50% discharge and need re-charging.
Most 100W panels provide 17V output and approximately 5.9 amps so you would be providing about 24amps at 17V with 4 panels BEFORE regulation to 48V...and this works out to 2.2amps or so at 48 volts with a good regulator. Figuring 5 hours of peak equivilent sunlight a day and some conversion losses this would allow you to replace about 10amphours at 48V back into your batteries.

[johnnyboats]

thanks for the reply, sounds like it will definitly be a trickle charge, that should be nice for keeping them topped up at anchor, and will still help over the years on generator time and cycling.

[chucklesR]

10 ah a day would be 15 days to fully recharge from a 50% drain with no other source of charge (mooring or no generator).

Powering a (48v) 30amp motor with 150ah of usable battery gives you 5 hours of run time, and if you are day sailing you'd need roughly a hour or less to just get out and sail (location dependent of course).

That 30ah for a day sail would be replaced in 3 days. Doing it twice on a weekend cruise plus minus overnight drain for house circuits (I run 40ah on average, but that's at 12v, you can call it an additional 10ah equivalent) and you'll be pretty much good to go week after week, if everyday is sunny enough to get you 10ah, 100% efficiency etc.

If the motor takes more than 30ah, adjust your throttle, run time etc.. and you'll be fine. Make sure you don't go short on system monitoring (meters).
Note normally I'm as anti-electric motor as it gets, for me this is a very positive post

[waltsn]

Also worth mentioning... 30 amps at 48 volts is 1440 watts - a little less than 2 hp. Works OK on a 16 foot boat but may not get you out of trouble on something even slightly larger.

[chucklesR]

Max current on the 48v Solidnav is 150 amp, at that rate there would be on one hour total run time at full throttle before cycling (damaging) the proposed battery bank.

As I said in my post, I was trying to be positive

SolidNav :: The first alternative for everyone

of course the controller is rated at 4kw, so the max you can get out of it is somewhere around 5.3hp, disregard the link's stated 24hp equivalent - that would be at 150amp x 48v, 7200 amp controller needed.

Gosh, reckon they are fudging the numbers a tad?

[sailingdog]

Chuckles-

Everyone knows that you can always trust a manufacturer's claims on their product completely. They'd never exaggerate or lie... would they???