solar and battery upgrades on e34-2?

Teranodon

Member III
When I installed refrigeration, I added a second West Marine 80Ah battery to my house bank, with a third battery for the engine. I see no need for solar, because cruising in my area includes sufficient motoring to keep everything topped up. When under way, I have my 9" chartplotter, VHF/AIS, depth, speedo, autopilot and wind instruments all turned on. At anchor, the fridge, Dickinson heater fan, cabin lights and masthead light eat up the juice. Again, a little bit of motoring takes care of everything. I keep track with DVMs at the nav station, just to be sure. Maybe if I had radar I would worry about having enough stored charge, but I doubt it because it would be used so infrequently (sort of like the Maxwell windlass). I have an electric outboard on order, and I'll be recharging it from the house bank. For me, solar is awkward physically, unnecessary, and just one more expensive thing that will eventually fail since it sits outside. But I'm interested to know what others think.
 
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Tin Kicker

Member III
Moderator
That's like asking what the best oil is. (Please don't)
It all depends on what you want to do with it and how much you want to spend.
I had mine on a $15 Harbor Freight 1.5W panel in the window and it kept one battery topped just fine.
With adding solar powered fans I now have a 50W panel ahead of the traveler on the 32-3.
If/when needed to stay on the boat for longer periods I have two 175W panels waiting in the shed. Currently think I'll probably just put one on a lifeline so it can be swung up when needed.

 

EGregerson

Member III
It all depends on what u want. They say do an Energy Audit. List the stuff u have; and the stuff you plan to get in the future; add it up to see what the amp load is; day, night, anytime. If ur day sailing and need power for knot meter, depth, auto pilot, reefer, then build it to that level. If cruising, then panels over the Bimini is what I dreamed of but never did yet. If anchoring out a night or 2 and sailing during the day, then build it to that level (anchor lights, reefer, stereo, interior light (consider bulb wattage; led or incandescent). My concern was having enuff in the bank to start the motor in the morning (and the macerator!). I put a 3rd starting battery in the coffin locker (where the nat gas cylinder used to be). Also have a honda gen for AC just in case. Be sure to mount the controller in a space that's ventilated and dry. good luck.
 

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Bobby Steele

New Member
We just bought a Jackery Explorer 1000 solar generator, and 100 Watt folding panel. We move the panel from side to side on the cabin top - as the sun demands. The generator sits under the nav-desk, and we run the cable from the panel through the hatch.
For us, this was a simple solution until we can get a better picture of what our actual needs will be in the future. Eventually, when we can afford it, we’d like toinstall LiIon batteries, and mount panels on davits (when we can afford them). Once I fix the dc to the fridge, I’ll be able to get a better idea of what we need to keep things cold.
It’s ‘baby steps’...
 

gc_sailor

Rule of Thumb, Electric E34-2
I just installed 3 Sunpower 110W flexible panels in series on my E-34-2 bimini (typically seeing 59v + 3-4 amps). With 2 across long-side they are a couple of inches too wide so I mounted them on Plaskolite panels to give the overhang support. Right now they are just tied on as I evaluate them. My engine is 48V electric with 300 Ah Lifeline AGMs. I use about 20% on average daily for the motor which the panels recharge fine. Also added a 48v-12v charger for my house batteries (flooded 160Ah) which I can vary the amperage on to match the solar input. Am going to add another 110w panel as the 3 are too close to the margin for my daily needs with both the motor and house use. Panels work much better when not sailing and regularly exceed specs. Shading from the main is mostly to blame but heel away from the sun is also a factor. I also have a Honda 2200 generator converted to propane for topping off the batteries every once in awhile. Can run it while motoring with no net loss on the battery charge. Just finished a 10 day 300 mile sail and had several days where I ended the day with 100% on both battery banks from solar. There might be a little regen contribution from the engine/prop if I'm sailing over 5 knots but it is minimal.
 

Teranodon

Member III
I just installed 3 Sunpower 110W flexible panels in series on my E-34-2 bimini (typically seeing 59v + 3-4 amps). With 2 across long-side they are a couple of inches too wide so I mounted them on Plaskolite panels to give the overhang support. Right now they are just tied on as I evaluate them. My engine is 48V electric with 300 Ah Lifeline AGMs.
I admit that I am confused by electrical propulsion. I motor with a 25HP diesel, which is 20 kilowatts. To get that power at 48 volts, you need a current of 400 amps, which would discharge a 300Ah bank in less than an hour. Recharging at "3-4 amps" would take days. I just don't get it. Is there something simple that I am missing?
 

Mark F

Contributing Partner
Blogs Author
Hi Stefan, you would never use 25hp to motor at a cruise setting.
 

Mark F

Contributing Partner
Blogs Author
Hi gc_sailer,
Have you posted any install posts for your EP system (other than the above)? Sounds like you are getting some pretty good performance out of you charging setup. I did find one post you posted and it looks like you have a 10kw motor, is that correct? I recently added a 320 watt panel to my EP/charging system (200ah lithium) and I'm getting pretty good results. I had to add refrigeration ;-)
 

gc_sailor

Rule of Thumb, Electric E34-2
No detailed posts on the install. Just added the solar and have used for 2 multiday cruises. Only running the motor for less than an hour most days which consumes about 20 amps. Cover that in about 6-7 hours of good sun. My house consumption is pretty low. Windvane auto pilot, refrigeration uses the most at about 30 amps/12v per day. Biggest consumer is my incandescent anchor light but I usually hoist a hi lumen lantern with rechargable lithiums into the rigging. Low power boat, sail down to 1.5 knots, wait for wind, added a drifter to my sail inventory which can tack the boat at 1.5 knots in 2 knots of a whispering breeze. Most sailors suck in the sweet smell of gas fumes a these speeds but clean air and quiet are my preferred choice.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
I note that, using about 2500 rpm as my normal cruising rpm, and with a clean bottom making 7 kts thru water.... I am not using too much of the theoretical HP of the engine. I could get the prop pitch reduced, perhaps, but I am not sure if the cost justifies it at present.
If I read it correctly we use about 14 to 15 KW of the power available.
Of course if we motor at 6 kts, we would use even less of the available KW.
Interesting that the advised sustained cruising rpm on these engines coincides with the peak of the torque curve.
 

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gc_sailor

Rule of Thumb, Electric E34-2
I admit that I am confused by electrical propulsion. I motor with a 25HP diesel, which is 20 kilowatts. To get that power at 48 volts, you need a current of 400 amps, which would discharge a 300Ah bank in less than an hour. Recharging at "3-4 amps" would take days. I just don't get it. Is there something simple that I am missing?
When you have electric you motor slowly. At full throttle you are correct. I can run the boat at just over 6 knots for an hour and completely drain the battery. The other day I was becalmed and had to get home so I ran the motor at 850 rpms which with a favorable current moved me along at around 3 knots. Easily covered the 6 miles in 2 hours using about 30 amps. Could have made this up with solar in 1 day.
 

gc_sailor

Rule of Thumb, Electric E34-2
As I mentioned I do have a propane generator that is quiet by most standards. I added the solar after killing the quiet solitude of a beautiful tranquil sunset at an anchorage on the Chester River While I still have to resort to the generator every couple of days solar keeps the peace much longer. If I take a rest day every 3rd day or so to maximize the solar even less generator time.
 

Teranodon

Member III
... I can run the boat at just over 6 knots for an hour and completely drain the battery.....
I understand. One of the great things about sailing (and this forum) is that everyone gets to equip and sail their boat any way they please. Where I sail, winds are variable, currents are strong, and there are lots of islands, rocks, shoals, pilings, ferries, crab pots, logs, inexperienced skippers, etc. Except for a daysail, would I leave the dock with only two cups of diesel fuel in the tank? I would not. And yet that is the energy equivalent of 300 Ah of 12V batteries. It's not just a matter of style or convenience. It's safety. What if a crew member is injured, or the weather deteriorates, or another boat is in distress? I want to have an engine that can run for hours at full throttle, if needed. I've done some long-distance sailing in boats the size of my Talpa: for example, an Atlantic crossing, three months trying to get through the Northwest Passage. Always, there were times when things went south unexpectedly. The engine, and the jerry cans lashed everywhere, saved our skins.

I have nothing against electric per se. I have an electric outboard on order at Seattle Boat Works (ePropulsion Spirit 1, the Torqeedo beater). But, for now, my Beta diesel stays.
 
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