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rachelsdad
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# Posted: 29 Sep 2017 04:43am
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I'll post pix soon but I'm done.
Basics: 9 Solarworld Sunmodule plus 260 poly on boat house. 8 Trojan 330 ah batteries.
Had to hand dig 86' trench to bury cable in metal conduit...fun at 58 years old.
See if this picture works
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rachelsdad
Member
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# Posted: 29 Sep 2017 05:00am
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Boat house
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rachelsdad
Member
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# Posted: 29 Sep 2017 05:03am
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All in one unit.
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rachelsdad
Member
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# Posted: 29 Sep 2017 05:07am
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Pretty sight.
Nice trees too
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Steve_S
Member
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# Posted: 29 Sep 2017 08:54am
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Hehehe, Welcome to the "Light Side" hehehehe. Looks Good and start enjoying the rewards of your efforts.
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Borrego
Member
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# Posted: 29 Sep 2017 09:54am
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Nice rdad!
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ICC
Member
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# Posted: 29 Sep 2017 10:15am
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Good to see you went with good equipment
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rachelsdad
Member
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# Posted: 29 Sep 2017 08:49pm
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All due to you all.
Great recommendations
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rachelsdad
Member
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# Posted: 29 Sep 2017 08:51pm
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Looks good
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rachelsdad
Member
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# Posted: 18 Nov 2017 05:24am - Edited by: rachelsdad
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Ok, since I cannot access the island during winter I pulled the battery bank.
This consisted of unhooking, hauling to dock, placing on boat, removing from boat lifting on to dock, humping to truck, lifting to bed of said truck, bringing home, humping from truck to garage....well you get the HEAVY idea.
I have 8 330 amp Trojans. What would be the best way to go Li. I have a neighbor who would buy my dino technology.
The math on them is not sitting right with me.
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Steve_S
Member
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# Posted: 18 Nov 2017 06:52am
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I've looked & looked and never found any chart or tool that you can put in what your existing battery config is to find what would be the equivalent (or close to) in LiIon. Granted I haven't looked in a couple of months but you would figure some battery co or solar distributor or someone like that would have done so...
Enter your existing battery system:
# of Batteries, Batt volts, # of Ahr @ 20 hr discharge rate, Bank Volts Output: [12,24,48,72]
Result: equivalent capacity LiIon = ???
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creeky
Member
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# Posted: 19 Nov 2017 01:36pm
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Come see me. I'm at bobolinksolar dot com
For an equivalent lithium pack you divide by 3 or 4 from lead. With lead you use the top 20% of capacity. With lithium you use the middle 60-80%.
Lithium also has a 15-20% efficiency gain on charge/discharge.
Peukert on lead is 1.29 to 1.34. Lithium is 1.
Sizing example: My previous 720 lb lead pack had 14kwh of energy. At 20% that's 3kw of usable power. A two module "PowerWing" lithium pack has 4.5 kwh of energy with call it 3.5 usable. Weighs less than 70lbs.
To compare there are any number of variables. Ballpark 1/3 ah to arrive at a similar capacity pack.
Lead is dead. Lithium rules!
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Ontario lakeside
Member
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# Posted: 19 Nov 2017 05:27pm
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Im so glad I missed the Lead acid days!
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FishHog
Member
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# Posted: 19 Nov 2017 05:37pm
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Quoting: rachelsdad Ok, since I cannot access the island during winter I pulled the battery bank.
why didn't you just leave them? I never remove mine through the winter months. Although I go through the winter, as long as they are charged up they won't freeze and will continue to charge and stay topped up.
Other than theft, I can't think of a reason to ever move them until they die.
Lithium is great, I agree, but with the one exception that you can't charge them below freezing. For that reason I'll stick with my lead until there is a better solution.
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creeky
Member
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# Posted: 19 Nov 2017 11:31pm
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You don't need to charge lithium while away. They're happy to sit for a year waiting for your return.
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FishHog
Member
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# Posted: 20 Nov 2017 06:33pm
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true, but unless I move them inside so they are heated, I can't charge while I'm there. My current installation is in an attached unheated room. I may give some thought to retrofitting my install and move them inside, but don't really have a spot to do that.
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rachelsdad
Member
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# Posted: 21 Nov 2017 04:59am - Edited by: rachelsdad
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The reason I don't leave them is I am not convinced that the panels will shed snow. See pic above. If you think I'm wrong and they will shed, I won't make the same mistake next year and leave all in place.
There was light snow on the panels in the morning, 7+/-, that did melt off so maybe I am overreacting.
I also assumed that they needed tending, (add water periodically).
As for lithium, I was under the impression that they could handle cold weather. It hit 30 below F a number of times up there last winter. So would this preclude lithium?? Then again, it would sure be a lot lighter.
Thoughts on my panel angle/fear of snow shedding??
Do I need to top off batteries during wither?....(good typo!)
Lithium freezing?
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rachelsdad
Member
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# Posted: 21 Nov 2017 07:01am
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Im so glad I missed the Lead acid days!
Look at all the fun you're missing tho!!!!!!!
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rachelsdad
Member
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# Posted: 21 Nov 2017 07:48am
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Ok, So I have a <16 kwh. I can get by with say 5?
bear with me, playing with pix again
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rachelsdad
Member
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# Posted: 21 Nov 2017 07:51am
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not sure if you can read the charge controller figures but it has
IN: 101 V, 284 Watts .04 kw
Battery: 27.5v, 10.3 amps.
This was late morning
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rachelsdad
Member
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# Posted: 21 Nov 2017 07:56am
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Can't post the charge controller figures but it has
IN: 101 V, 284 Watts .04 kw
Battery: 27.5v, 10.3 amps.
This was late morning
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NorthRick
Member
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# Posted: 21 Nov 2017 02:48pm
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Quoting: rachelsdad The reason I don't leave them is I am not convinced that the panels will shed snow. See pic above. If you think I'm wrong and they will shed, I won't make the same mistake next year and leave all in place.
I doubt those panels would shed snow until you have several days of above freezing weather.
If it were me, I'd just make sure they were fully charged, top of the water, and disconnect them so there is no draw at all on them. Then I'd plan to make one or two mid-winter trips to the place and top off the charge with a generator. Batteries don't self-discharge much in the cold. They also don't lose water just sitting there.
If a mid-winter trip is out of the question, I'd get a small panel and a cheap charge controller. Hang the panel vertically on the side of the boathouse and connect it to the controller and batteries. Disconnect the other system from the batteries. The small panel won't get buried by snow and only needs to produce enough juice to keep the charge controller on and the batteries topped off. The batteries would not lose enough water to matter over the course of the winter.
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creeky
Member
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# Posted: 21 Nov 2017 03:28pm
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There was a guy who killed his lead battery pack year one. But he went to his winter cottage and used his batteries without charging. Never got his panels set up is what I remember.
Lithium can be used down to -25C. Lead can be used down to -18C.
Warm lithium before charging. One reason lead often goes outside is it off gases corrosive stuff. With lithium there is no off gassing. And the much smaller size ... means its easier to find a place for them in conditioned space. I mean look at Lakesides lithium setup. His battery is in a kitchen drawer. Yet he has 720lbs of lead worth of storage (more but. meh).
I have my battery pack inside an insulated box. I use a combination of the inverter (waste heat) and battery warmers to keep the batteries above 5C. I am in the process of adding an IFTTT schedule with zigbee switches/thermometer.
Anyway. With IFTTT (if this than that) when the temp reads less than 5 the heater will come on. I would really like to tie that to battery voltage but I don't have a way to do that yet. Eventually. Probably means arduino. I don't have all the time in the world. smile.
If you're leaving for the winter with lithium. Discharge to 60-80%. Turn everything off. Leave for the winter. Done.
The panels will definitely not shed snow. I just got back from 4 days away. My panels were almost melted clear. Sunny above freezing today. But for 3 days they were covered and the batteries were extremely low. Luckily. With lithium. Who cares!
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rachelsdad
Member
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# Posted: 22 Nov 2017 02:47am
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I'm down here in the Excited States, so my Celsius to F conversion took me a few.
It gets as low as -30 Celsius on several occasions and there is no heat so it would be hard to temper space.
So NorthRick/Creeky, it's just the nature of the beast that panels don't shed, or is it my angle of install?
It appears I have to haul either way
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razmichael
Member
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# Posted: 22 Nov 2017 07:10am
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Not going to get into the Lead vs Lithium discussion here but just provide some experience. My cabin in in Quebec, Canada so very very cold winters with lots of snow. I have 2 Trojan T105s and 330 w panels so a small system. Panels are pole mounted near the ground. In the fall when I lock up, I drop the angle of the panels to about 12 degrees if I remember correctly (close to vertical). Main power is off in the cabin but I keep a separate circuit running from the charge controller that powers a couple of game cameras, a motion sensor and a LED flood light (connected to the motion sensor).
The first winter I left the batteries there I was very nervous coming up in March - no apparent issues. Three more winters and there have been no issues. Two years ago I did come up in the winter to check after a snow storm - panels had some snow on them but shed during the day - batteries were fully charged. I consider the draw to be minimal and the panels will continue to trickle charge (worse case with snow) throughout the winter. Given:
At a 40% state of charge, electrolyte will freeze if the temperature drops to approximately -16 degrees F. When a battery is fully charged the electrolyte will not freeze until the temperature drops to approximately -92 degrees F
I do not worry about leaving them out there - plus, even in extreme cold, they can continue to power the small circuit and be charged.
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rachelsdad
Member
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# Posted: 22 Nov 2017 07:23am
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Ok Raz...I originally thought I'd do the same with exception of adjusting panels.
I'll ask my installer if there is a way to make them adjustable. (He was offered a week in the place for free with his family in 2018, so he'll be glad to "help").
Well the owner of the store I bought the batteries from is a friend, he has them in his shop on a rack, set up identically to how they were installed. He'll tend them all winter. I guess I'll sleep better this winter, (I'll need plenty of rest to haul those mudders around again!!).
Thanks all!
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rachelsdad
Member
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# Posted: 22 Nov 2017 07:25am
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Raz,
I was thinking of doing a smaller system on another out bldg. You have 2 T105's and 2 330 watt panels?
What CC and inverter, (if any) are you using?
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razmichael
Member
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# Posted: 22 Nov 2017 08:56am
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Parts of this system are 7 or more years old (I originally modified a pop-up trailer for use at the lake and then migrated those components to the cabin when built). Lights, ceiling fan, water pump etc are all 12V. 120AC is used for the vacuum, wife's hair dryer, blender etc as required). If I was starting today I would likely do some things differently due to cost changes, technology etc, but I have to say the system works great with minimal maintenance and gives us all the comforts we need/want at a cabin. Obviously very different use cases for different people (hence staying out of the Lead vs Li discussion).
2x165 panels mounted on a homemade ground mount pole - seasonally adjusted
2xT105 (in series for 12VDC)
Xantrex hf1800 inverter (only generally turned on when 120AC needed)
ProStar PS-30 controller - Use the "load" circuit only powers cameras and motion/LED floods - this stays on when main power to cabin is turned off. This has it's own low voltage cut-off.
Sterling ProLatch R 80 amp latching relay - Main Cabin 12VDC runs through this to act as a low voltage cut-off.
Xantrex hf1800 inverter - also has it's own low-voltage cut-off (and only generally turned on when 120AC needed)
Some diagrams etc in my build thread. I fully admit the electrical is more complex than it really needed to be but cold Canadian winters give you lots of time to over-plan (and it's fun)
Cabin Build
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rachelsdad
Member
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# Posted: 23 Nov 2017 06:01am
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cold Canadian winters give you lots of time to over-plan (and it's fun)
Agreed, it has been a blast and the folks on this forum have been an invaluable source of help!!
Thank you sir!
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