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Post by Don Reaves on Dec 13, 2014 19:15:01 GMT
Vasko,
I'm impressed with your battery setup. So you have 100 3-cell holders in parallel? Does that mean that the nominal voltage of your battery is 11.1 V (3 x 3.7V)? Do all of your systems work well with that voltage?
Aside from the voltage issue, the only thing I'd be concerned with a system like this is that you have 300 batteries making a total of 600 connections that might eventually have issues with corrosion. Did you do anything to make sure this isn't a problem?
Thanks, Don
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Post by dbostrom on Dec 13, 2014 19:24:35 GMT
Fascinating info on lithium batteries, vasko, and thanks. You have created the Tesla Motors battery of boating! The Opportunity rover on Mars is a good benchmark for how lithium batteries can perform if they're treated scrupulously; scads of cycles can be had.
Something to keep in mind w/PV panels (and most people here probably know it already) is that in a situation with two panels each partially shaded, the MPP of each panel will typically be different, making the charge controller's life difficult.
As well, unless they're built specifically (and expensively) to be shade tolerant, monocrystalline panels suffer drastic production losses even with modest amounts of shading. As we know, sailboats cast lots of shading from rigging.
There's a solid argument to be made for amorphous panels even though their nominal efficiency is lower; amorphous cells more or less lose output in proportion to the area of the cell shaded, unlike monocrystalline systems where the geometry of the shade is what counts. Net production of amorphous cells is typically better in any situation involving uncontrollable shading despite their inferior efficiency.
Some time ago I was involved in a project to design vandal-resistant PV power sources for a telemetry network. We were delighted to find that punching holes through our candidate amorphous panels barely affected their operation; the size of the hole determined the loss of power output. We found similar results with shading; shading looked like a loss of area to the panel, not loss of a cell string.
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Post by singoviv on Dec 14, 2014 0:13:34 GMT
Vasko, I'm impressed with your battery setup. So you have 100 3-cell holders in parallel? Does that mean that the nominal voltage of your battery is 11.1 V (3 x 3.7V)? Do all of your systems work well with that voltage? Aside from the voltage issue, the only thing I'd be concerned with a system like this is that you have 300 batteries making a total of 600 connections that might eventually have issues with corrosion. Did you do anything to make sure this isn't a problem? Thanks, Don 200ah lithium ion battery is $2500 AUD ( and we get ripped off down under). Two normal connections - + and - www.batteriesdirect.com.au/shop/product/23886/v-lfp-12-200.html
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Post by sailbleu on Dec 14, 2014 8:11:05 GMT
Ever thought about howmany AGM 's you can buy for the money you spend on Li-ion ? These batteries also have a high risk for explosion and fire when charging issues occur. The weight factor is very interesting , but you pay alot of money to be ahead of the curve . I guess it's like solarpanels , about 15 years ago I've paid 350 Euro for a 50 watt panel , one panel. A few weeks ago I paid 600$ which is about 500 Euro for 4 extra flexible 80 watt bimini panels . Comes to 125 Euro per panel. What's next. Same thing for Li-ion , I guess we're better off waiting untill the electric car really breaks through , mass production of the batteries will rapidly bring the prices down . But than again , we all make our own choices of course.
Regards
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Post by singoviv on Dec 14, 2014 9:24:03 GMT
It's space, weight and capacity. 1000 cycles is good value for money.
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Post by hoppy on Dec 14, 2014 9:33:13 GMT
These batteries also have a high risk for explosion and fire when charging issues occur. Youtube is full of lipo fires. Admittedly quite a few are by people trying to see what it takes to get them on fire. It does make me worry a bit about charging and storing the lipo's I use in my Quadcopter as I live in an apartment. I'd be a bit cautious about using lipo's on the boat.
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Post by sailbleu on Dec 14, 2014 10:19:25 GMT
Indeed Hoppy , it even goes as far many Chinese sellers cannot/will not/may not send you items by plane containing Li-ion batteries , or lipos as you call them. Unless it's done by special transport , and Fedex seems one of the few providing that kind of service. Unfortunately fedex is a bit of a cheat. I don't want to use that courier anymore because they also charge you a fee on the customs that sometimes have to be paid. They pay it for you without you asking it , and subsquently claim it back from you adding a commission to it . Unasked and uncalled for. They have a minimum administrative quote which sometimes exceeds the customs that need to be paid. They always , ALWAYS , declare chinese items to the customs for obvious reasons. NO MORE FEDEX for me. But that's off topic.
Regards
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Post by vasko on Dec 14, 2014 13:05:52 GMT
Vasko, I'm impressed with your battery setup. So you have 100 3-cell holders in parallel? Does that mean that the nominal voltage of your battery is 11.1 V (3 x 3.7V)? Do all of your systems work well with that voltage? Aside from the voltage issue, the only thing I'd be concerned with a system like this is that you have 300 batteries making a total of 600 connections that might eventually have issues with corrosion. Did you do anything to make sure this isn't a problem? Thanks, Don in reality the 3.7v li-ion cell means 4.2v fully charged to 3.5v fully discharge corrosion - was my main concern too - after some tests I found out that actually that if the cell is not close to salt water seacock or pipe there is no corrosion and vise verse near sea water seacock there was corrosion - when left the cells open to the air - in the end after some tests I found the place that I decided will be OK and decided that if they last 5-7 years it is enough for me and sprayed all non soldered connections with wd40 and for the soldered I covered the bus with heatshrink tube and the whole battery covered with heatshrink folio - and we will see over the years how it will beehive..
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Post by vasko on Dec 14, 2014 13:10:04 GMT
Ever thought about howmany AGM 's you can buy for the money you spend on Li-ion ? These batteries also have a high risk for explosion and fire when charging issues occur. The weight factor is very interesting , but you pay alot of money to be ahead of the curve . I guess it's like solarpanels , about 15 years ago I've paid 350 Euro for a 50 watt panel , one panel. A few weeks ago I paid 600$ which is about 500 Euro for 4 extra flexible 80 watt bimini panels . Comes to 125 Euro per panel. What's next. Same thing for Li-ion , I guess we're better off waiting untill the electric car really breaks through , mass production of the batteries will rapidly bring the prices down . But than again , we all make our own choices of course. Regards that is why I especially mentioned the risk with li-ion batteries.. and why I used a protected li-ion cells e.g. they cannot be over charged or over discharged - and added a 3 temp gauges for additional piece of mind if some of cell's fail... but still agree there is a potential risk
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Post by dbostrom on Dec 14, 2014 19:46:22 GMT
Off-topic but I have not been on this board for long yet I'm not even slightly surprised to hear that Hoppy has a quadcopter. Quad and sailing fans shouldn't miss PigeonVision.
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Post by hoppy on Dec 14, 2014 22:27:38 GMT
Off-topic but I have not been on this board for long yet I'm not even slightly surprised to hear that Hoppy has a quadcopter. Quad and sailing fans shouldn't miss PigeonVision.I learnt the hard way that sailing and quads shouldn't mix jeanneau.proboards.com/thread/3342/so40-helipadWhat happened was better than having a lipo fire at least
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Post by deweyandjoanne on Nov 2, 2019 18:38:11 GMT
On our 39i I tend to switch off all the batteries (including the toggle switches for the bow thruster and windlass) and also the breakers on the main panel for the battery charger and immersion heater (on the basis that the batteries should already be charged) but like now if the weather is cold and I have an oil filled radiator and a dehumidifier on just leave the AC outlet breaker on. Maybe not perfect but has served me well for 7 seasons. I don't have a galvanic isolator, but have read the threads, but to date have not had any problems whatsoever - in the summer when I don't need the mains I tend to unplug the shore lead anyway Enjoy the 39i, great boat
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Post by deweyandjoanne on Nov 2, 2019 18:40:31 GMT
I have so 37. The boat is new to me Have manuals but the battery switch off/on positions are clear enough. Can someone provide guidance? Thanks
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