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22-06-2018, 08:58
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#16
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Marine Service Provider
Join Date: Aug 2006
Location: La Paz, Mexico
Boat: 1978 Hudson Force 50 Ketch
Posts: 3,920
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Re: Is lithium really safe ?
Quote:
Originally Posted by john61ct
Other lithium chemistries, not safe enough for boating House bank usage.
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Ya...if I had a dollar for every time another cruiser looked at my LiFePO4 bank and said, "That's that blew up that Plane, I wouldn't have them on my boat"....
__________________
Rich Boren
Cruise RO & Schenker Water Makers
Technautics CoolBlue Refrigeration
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22-06-2018, 09:02
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#17
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cruiser
Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,317
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Re: Is lithium really safe ?
Dunning-Kruger at work
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22-06-2018, 09:11
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#18
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Registered User
Join Date: Apr 2013
Posts: 11,002
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Re: Is lithium really safe ?
Quote:
Originally Posted by gmakhs
The idea was to start with one now for test purposes and then upgrade to a 48volt bank that I would be able to feed a 5 kw electric motor for about 1to 5 hour per time .
The size and kilos of 100ah 4*12v lithium batteries is the 1/3 of agm and lead .
Later the plan is to remove completely the engine , through for now I am.going with the hybrid model of if , which I have test and works nice .
The plan is not to save on fuel ,with half a litter per hour my engine uses it will take centuries, the plan is to be able to slow motor without the vibrations and the noise .
The cost of batteries and motor is about 1500 euro , the same motor will be used to power a scuba diving compressor.
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Currently auto companies buying in bulk are paying more than $200/kwh. To run your motor at 5kw output for 3hrs you need 15kw of capacity. That's $3000 before you add motor, controller and other ancillary equipment. Unless you are planning to do some home-brew system from a salvaged electric car, I would expect you are paying even more. Given your question, the home-brew system is likely not a good idea given your knowledge and experience.
4 - 100amp-hr 12v batteries contain 4.8kwh of capacity. Of course, you probably don't want to use more than around 80-90% to avoid damaging the batteries, so figure 4kwh usable or about 45min at 5kw.
By the way, how are you planning to test this out before removing the old motor?
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22-06-2018, 09:51
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#19
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Registered User
Join Date: Sep 2013
Location: Alert Bay, Vancouver Island
Boat: 35ft classic ketch/yawl.
Posts: 1,980
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Re: Is lithium really safe ?
Second the comments that you will spend a great deal of money for no real benefit. Running Lithium will be several time more expensive and unless you have high demands and big chargers you don't get any advantage. Spill risk with FLA's is minimal if you have a battery box and going to seals increases cost about x4 (then another x4 for lithium). Make sure you look at 'reel world' stuff when deciding. E.g. what happens if you get a charger fault! Do you right off you bank, does it catch fire or explode or do you just top it up and loose a few A/H capacity!
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22-06-2018, 10:06
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#20
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Registered User
Join Date: Aug 2016
Posts: 987
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Re: Is lithium really safe ?
And the lithium batteries in vape pens are really, really small...
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22-06-2018, 10:14
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#21
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Registered User
Join Date: Mar 2016
Location: North of San Francisco, Bodega Bay
Boat: 44' Custom Aluminum Cutter, & Pearson 30
Posts: 599
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Re: Is lithium really safe ?
Lead acid batteries do explode. I have seen two explode once when a firefighter opened a battery box on a generator, the top of the battery blew up in his face covering him in acid. We think it must have been a static spark that set it off. Lucky for him there was a garden hose close by to rinse his face, he could not see for 3 days from the acid burns. Other one somebody cross polarity on a set of batteries.
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22-06-2018, 10:24
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#22
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Registered User
Join Date: Jan 2014
Location: Martinique
Boat: Fortuna Island Spirit 40
Posts: 2,298
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Re: Is lithium really safe ?
Quote:
Originally Posted by Peregrine1983
And the lithium batteries in vape pens are really, really small...
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LOL, another one Rich... Sigh, we can't even get people to read a thread before posting.
It won't do any good, but I will post it anyway. The lithium batteries in Vape devices are COMPLETELY different technology than LiFePo4. Do some research on lithium chemistries.
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22-06-2018, 10:29
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#23
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Registered User
Join Date: Aug 2016
Posts: 987
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Re: Is lithium really safe ?
Quote:
Originally Posted by travellerw
LOL, another one Rich... Sigh, we can't even get people to read a thread before posting.
It won't do any good, but I will post it anyway. The lithium batteries in Vape devices are COMPLETELY different technology than LiFePo4. Do some research on lithium chemistries.
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You're right to call me out. I just thought the video was amusing. Sick sense of humor I guess. I will now go into a quiet corner and read about lithium batteries .
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22-06-2018, 14:00
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#24
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Registered User
Join Date: Sep 2017
Location: Nantucket, Ma
Boat: 1977 GulfStar 40 (Ted Hood)
Posts: 49
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Re: Is lithium really safe ?
As Mrs Google's W class left Newport a couple of years ago underway to Nantucket; with a new Lithium set up, in a locker I believe, with out a rate of rise heat detector; burnt to the waterline. No one was injured due to there being another near by boat. She sank and it was over in a matter of minutes.
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22-06-2018, 14:29
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#25
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Registered User
Join Date: Jan 2010
Location: Portland, Oregon, USA
Boat: 31' Cape George Cutter
Posts: 3,270
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Re: Is lithium really safe ?
To correct the record: you can air ship gel and agm batteries - I have done it. You can also air ship a dry-charged liquid battery, and source the acid locally. It is the liquid acid spill that is the concern.
I think it is great that we have early adopters here on CF who are willing to go the extra mile to explore lithium technology. Eventually it may supplant lead technology, but for now it is still at the bleeding edge - meaning it is expensive and really needs owners who enjoy doing the extra work to adapt the 12VDC systems. The main advantage is kWH/weight, which is not a concern for my application. But mostly it is the extra cost, for the batteries and the new charging systems, that put me off. YMMV
Any battery we would use contains enough stored energy to cause trouble with a faulty circuit. There is no substitute for a properly designed and maintained 12V system, and the potential for fire always exists if not. Still, lithium does require a bit more sophistication in the controls, and IMHO is not appropriate for owners who are not excited by technology - yet.
Greg
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22-06-2018, 15:54
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#26
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Registered User
Join Date: Nov 2017
Posts: 458
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Re: Is lithium really safe ?
Quote:
Originally Posted by piberman
Airlines usually do not allow freight shipments on lithium batteries. They can and do explode. Have never known of a lead acid battery exploding. Save shorting out the terminals. With good care kept charged a lead acid can easily last a decade. With heavy duty plates much longer. Lead acid is simple technology. It’s all in the plates. Heavier plates are always better. Drawing down below 50% severely shortens life. Besides its character building to add distilled water a few times a year.
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All batteries can explode. Lead acid explode if an internal short occurs from manufacturing or just failure. External shorts will also explode. '
If you see a bulging battery, hot battery, or boiling battery- get rid of it. Like immediately throw it overboard.
When connecting cables or working around batteries, use eye protection.
Annually I am involved with batteries that explode- and as such can only strongly suggest respect them.
The lithium discussion is to broad- but experience suggests that research will not be a waste- the new technology is coming fast and will probably be standard within a decade.
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22-06-2018, 16:04
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#27
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Registered User
Join Date: Sep 2006
Posts: 9,398
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Re: Is lithium really safe ?
Quote:
Originally Posted by piberman
Have never known of a lead acid battery exploding.
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I was helping a friend of mine do a refit on a boat he'd bought. He took the lead acid batteries home to keep them charged while we worked on the boat.
One day when I showed up he was in overalls covered in bleached spots.
One of the batteries had exploded. Luckily he hadn't been wearing the overalls at the time, they were hanging in the shed.
They do explode. It's not even all that rare.
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22-06-2018, 17:10
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#28
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Registered User
Join Date: Aug 2011
Location: Queensland, Australia
Boat: Endeavourcat 30
Posts: 238
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Re: Is lithium really safe ?
Probably safer than FLA or AGM and hey, I like waking up in the morning and my LiFePO4 house bank is still at 13.2 volts.
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22-06-2018, 17:19
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#29
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Registered User
Join Date: Jul 2014
Location: Crete , Greece
Boat: Beneteau first 26
Posts: 670
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Re: Is lithium really safe ?
Quote:
Originally Posted by valhalla360
Currently auto companies buying in bulk are paying more than $200/kwh. To run your motor at 5kw output for 3hrs you need 15kw of capacity. That's $3000 before you add motor, controller and other ancillary equipment. Unless you are planning to do some home-brew system from a salvaged electric car, I would expect you are paying even more. Given your question, the home-brew system is likely not a good idea given your knowledge and experience.
4 - 100amp-hr 12v batteries contain 4.8kwh of capacity. Of course, you probably don't want to use more than around 80-90% to avoid damaging the batteries, so figure 4kwh usable or about 45min at 5kw.
By the way, how are you planning to test this out before removing the old motor?
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The usual usage of the motor is about 30 percent on normal conditions, the 5kw is the peak that most of the times is not needed .
The motor will be placed over the reverse gear and connectedto the shaft with a pulley ,like a shaft generator , ofcourse with 1-1 ratio or 2 to 1
The engine has currently 2 to 1.
I have tried the hybrid version of the setup on another boat with lead batteries , it works for the purpose I want it , now with lithium I hope to be able to remove the motor completely .
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25-06-2018, 09:39
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#30
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Registered User
Join Date: Apr 2013
Posts: 11,002
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Re: Is lithium really safe ?
Quote:
Originally Posted by gmakhs
The usual usage of the motor is about 30 percent on normal conditions, the 5kw is the peak that most of the times is not needed .
The motor will be placed over the reverse gear and connectedto the shaft with a pulley ,like a shaft generator , ofcourse with 1-1 ratio or 2 to 1
The engine has currently 2 to 1.
I have tried the hybrid version of the setup on another boat with lead batteries , it works for the purpose I want it , now with lithium I hope to be able to remove the motor completely .
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If you have very low expectations a 2hp (roughly 30% of 5kw) motor in calm conditions will move a 26' boat but you will be lucky to make 3kts and if there are any waves or head winds, you may not be able to make any headway. Of course, you are probably down closer to 1.5hp at the prop by the time you take losses into consideration with a rube goldberg pulley system.
If you just need something to get on and off a mooring, it may do the trick but if that is all you need, you will never save enough on fuel to justify the cost and your house loads are so low that there is no benefit there.
If you just want a science experiment to build a hybrid, go for it.
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