What type of Solar?

[john61ct]

Originally Posted by Mike OReilly

Sorry John, my apologies. Too much flipping back and forth, trying to be efficient in responding. You definitely did not recommend buying second hand. My bad.

You’re probably right … best to wait. It’s not a burning need. And our plans for the coming season is far more modest than previous.

What I really should do is reconfigure my battery compartment to accept 6v batts. I don’t quite have the height for them right now, which is why I’ve stuck with Group 31.

That would be a great investment.

Deka "Duracell" FLA GCs at $1 / AH @12v in 200AH increments are an incredible value, as are the Trojan T-105s RE version if available locally.

[SFS]

What is the difference between the T-105 and the T-105RE, besides an almost doubling in price?

[StuM]

Originally Posted by SFS

What is the difference between the T-105 and the T-105RE, besides an almost doubling in price?

The blurb for the RE talks about "renewable energy" and "smart carbon".

Anything touting "green" will end up costing you twice as much whether it's better or not.


But seriously, according to their respective data sheets, the RE have an a much higher "expected cycle life". All other specs are the same for both.

T-105
20% DOD about 3000 cycles, 80% DOD about 750 cycles.
T-105RE
20% DOD bout 4000 cycles, 80% DOD about 1000 cycles.

[Quadrille in JB]

Sunpower x-22 360 watt/ 68v panels provide the highest output that I know of per sq ft. I have two mounted on my arch and I’ve seen over 360w output on sunny days when my Victron 100/30 mppt controllers were in bulk mode and battery voltage was lower. These panels are 40.5” x 60.5” but Sunpower is really proud of them $$$$.
Last boat had only 1 panel running water maker and refrigerator, new boat has 2 panels with an additional freezer. Batteries have stayed topped up all winter with refrigeration running 24/7.m

[john61ct]

> 20% DOD bout 4000 cycles, 80% DOD about 1000 cycles.

The 50% DoD point should really be used for apples to apples.

Yes if RE is over $3 / AH @12v, I'd say only worth it for long-term cruisers going far from home needing super predictability.

Sometimes the regular T-105's are below $1.50 / AH, but personally I'd put the Deka's as better value even then.

Really, gets to be subjective judgements at that point, especially dependent on how much difference saving a few hundred makes for you.

Some would rather pay 4x for Rolls / Surrette just to avoid the bother of replacing any more frequently than necessary, maybe a decade or more.

But if you don't think you'll be able to treat them really well, no point in getting better grades, even the best gets murdered quickly by abuse.

[skipgundlach]

Originally Posted by Quadrille in JB

Sunpower x-22 360 watt/ 68v panels provide the highest output that I know of per sq ft. I have two mounted on my arch and I’ve seen over 360w output on sunny days when my Victron 100/30 mppt controllers were in bulk mode and battery voltage was lower. These panels are 40.5” x 60.5” but Sunpower is really proud of them $$$$.
Last boat had only 1 panel running water maker and refrigerator, new boat has 2 panels with an additional freezer. Batteries have stayed topped up all winter with refrigeration running 24/7.m

Nice!

Just a reminder that you will need to clean them from time to time - Sunpower's recommendation is that they have a slope for runoff cleaning...

[Quadrille in JB]

Skip
Thanks for the cleaning tip. It’s sometimes very apparent when a great blue heron decides to spend the night on the PV panels. They are slightly sloped to the rear (I hesitate to say stern as it slopes away from the stern).
They get rinsed off regularly while at the dock and fortunately/unfortunately our cruising season is often pretty rainy.
Our dock master suggested installing an electric fence around the panels.