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17-01-2013, 13:47
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#1171
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Registered User
Join Date: Nov 2011
Location: Fethiye Turkey
Boat: Lagoon 440
Posts: 2,954
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
Google Translate
Very informative, albeit a translation. Picture shows a ruptured battery, not a huge issue!
__________________
"Political correctness is a creeping sickness that knows no boundaries"
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17-01-2013, 13:49
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#1172
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Nearly an old salt
Join Date: Jun 2009
Location: Lefkas Marina ,Greece
Boat: Bavaria 36
Posts: 22,801
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Quote:
Originally Posted by Maine Sail
They were not advertised or even sold as brand new cells. They were clearance cells, but are guaranteed to perform as new and carry a new warranty. I am getting ready to test the capacity of mine in the next few days..
"Our clearance items come with full factory warranty. They may be overstock inventory of batteries from previous production stock. Items in clearance may be batteries used during production tests for less than 25 cycles. Please be assured that these items are all the very best of quality and are being offered at great Prices"
$1032.00 for four 400Ah cells Winston + $250.00 shipping... Not bad and I am certainly not complaining that they have a few cycles on them...
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Remember Li ages irrespective of cycles. Just sitting on the shelf they are slowly dying. LiCo is bad in this respect Li Ferrous has a better shelf life, but how much is a subject of much debate. Current data says about 2-3 for LiCo with 5 for LiFe, there not much data on large prismatics yet.
Hence these cells could only have 2-3 years left on them !!!
Dave
__________________
Interested in smart boat technology, networking and all things tech
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17-01-2013, 13:53
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#1173
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Nearly an old salt
Join Date: Jun 2009
Location: Lefkas Marina ,Greece
Boat: Bavaria 36
Posts: 22,801
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Quote:
Originally Posted by Lagoon4us
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Yes the rupture is merely used as a bogey man picture no actual reference to anything
Dave
__________________
Interested in smart boat technology, networking and all things tech
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17-01-2013, 13:58
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#1174
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Registered User
Join Date: Dec 2012
Location: Yuma, AZ
Boat: USS Asymptote
Posts: 257
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
Quote:
Originally Posted by goboatingnow
Remember Li ages irrespective of cycles. Just sitting on the shelf they are slowly dying. Hence these cells could only have 2-3 years left on them !!!
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That sure better not be the case. My $700 pair of AGMs only lasted 4.4 years. If these $850 LFPs die in the next three years, I'll be really PO'd.
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17-01-2013, 14:00
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#1175
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Registered User
Join Date: Feb 2011
Location: Northern and Southern California
Boat: too many
Posts: 3,731
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
Good article Lagoon4us, thanks for sharing. I'm at 44 1/2 hours on my 30 watt load and all cells are 3.31 volts, and this is pack #2 that had some in-balance. 1335 w-hr, but I expect more than the rated 1280 w-hr at a 0.023 C rate.
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17-01-2013, 14:02
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#1176
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Registered User
Join Date: Dec 2011
Location: On the boat
Boat: DeFever 44
Posts: 292
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Quote:
Originally Posted by nimblemotors
I'm sorry, but you haven't done your research.
If it was just BMS vendors selling you stuff that wasted money for useless features it wouldn't be so bad, but a system which top-balances on every charge is reducing their life, and some are even dangerous enough to create a fire and destroy YOUR ENTIRE BOAT.
JackB
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Jack, We may agree more than you think...I agree top balancing every cycle is not needed, can reduce cell life if balanced every cycle that way, and if poorly engineered boards are used can present a fire risk. But the system I use does not start balancing until 3.55V, and I only charge to 3.5V maximum usually less. So no balancing occurs normally. I did use it to help fine tune the installation balance. But it was really little help with 1200 Ah cells. So it's function is just a LCD voltage monitor with HVC and LVC solenoid.
My only point is I think cell level voltage monitoring is required, something as simple as the Celllog 8 and a EV200 solenoid does the trick for next to nothing. If you can't or don't want to engineer the disconnect...at least have an audible alarm on the Celllog 8. It's not very expensive.....
You appear to follow Jack Rickard, and so do I. I like his philosophy, but I believe this application is a bit different, and this level of adjustment is justified. Bob
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17-01-2013, 14:22
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#1177
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Registered User
Join Date: Mar 2011
Location: Nova Scotia Canada
Boat: Wharram Tiki 46
Posts: 1,321
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
Quote:
Originally Posted by Maine Sail
They were not advertised or even sold as brand new cells. They were clearance cells, but are guaranteed to perform as new and carry a new warranty. I am getting ready to test the capacity of mine in the next few days..
"Our clearance items come with full factory warranty. They may be overstock inventory of batteries from previous production stock. Items in clearance may be batteries used during production tests for less than 25 cycles. Please be assured that these items are all the very best of quality and are being offered at great Prices"
$1032.00 for four 400Ah cells Winston + $250.00 shipping... Not bad and I am certainly not complaining that they have a few cycles on them...
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So, what is the code on your cells ? Am I reading it correctly ?
Cheers,
JM.
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17-01-2013, 14:28
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#1178
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Registered User
Join Date: Dec 2011
Location: On the boat
Boat: DeFever 44
Posts: 292
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Quote:
Originally Posted by senormechanico
How?
If the BMS keeps the cells within their voltage parameters, I don't see a problem.
Please explain.
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The reference was probably that a couple of homebuilt EV fires MAY have been caused by either simple balance boards or full BMS boards. Both devices attach to each individual cell and upon reaching full charge voltage shunt power from the battery cell creating heat to keep the high cells from charging further while the low cells reach full charge. The concept is sound, but the execution has not always been engineered well and beyond the possible fires...there have been various issues with failed boards, mostly unnecessarily draining cells beyond repair. Or improper use where chargers overrun the shunting capacity. For our house banks and chargers, none of these balancing circuits will stop a runaway charger except by opening the solenoid if so equipped, and if it works.....
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17-01-2013, 14:34
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#1179
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֍֎֍֎֍֎֍֎֍֎
Join Date: Apr 2006
Posts: 15,136
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
FWIW, Balqon apparently is a subsidiary of Winston and Winston's Seven One company. From Balqon's own web site at
Balqon - Advanced Transportation Solution
21-Dec-2010
Balqon Raises $5.0 Million Through a Private Placement of Its Common Stock and Warrants
Balqon Corporation (OTCBB: BLQN), a developer and manufacturer of zero-emissions heavy-duty electric vehicles and drive systems, completed a $5.0 million private placement of its common stock and warrants to purchase common stock on December 14, 2010. The investor in the private placement was Seven One Limited. Balqon filed a Current Report on Form 8-K with the Securities and Exchange Commission on December 17, 2010 that provides further details of the transactions described above and below.
On December 14, 2010, Balqon also entered in to a Distribution Agreement with Seven One Limited under which Balqon was appointed the exclusive distributor in the United States for lithium iron phosphate batteries and high voltage charging systems manufactured by Winston Battery Limited.
Seven One Limited holds worldwide distribution rights with respect to the high-capacity lithium iron phosphate batteries and high voltage charging systems manufactured by Winston Battery Limited. Both Seven One Limited and Winston Battery Limited are Shenzhen, China-based companies that are headed by leading battery technology scientist, inventor and entrepreneur, Mr. Winston Chung.
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17-01-2013, 14:38
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#1180
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Nearly an old salt
Join Date: Jun 2009
Location: Lefkas Marina ,Greece
Boat: Bavaria 36
Posts: 22,801
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Quote:
Originally Posted by diugo
That sure better not be the case. My $700 pair of AGMs only lasted 4.4 years. If these $850 LFPs die in the next three years, I'll be really PO'd.
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Well see that's the data to date
Dave
__________________
Interested in smart boat technology, networking and all things tech
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17-01-2013, 14:40
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#1181
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Nearly an old salt
Join Date: Jun 2009
Location: Lefkas Marina ,Greece
Boat: Bavaria 36
Posts: 22,801
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Quote:
Originally Posted by deckofficer
Good article Lagoon4us, thanks for sharing. I'm at 44 1/2 hours on my 30 watt load and all cells are 3.31 volts, and this is pack #2 that had some in-balance. 1335 w-hr, but I expect more than the rated 1280 w-hr at a 0.023 C rate.
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Why Peukerts is virtually unity !
Dave
__________________
Interested in smart boat technology, networking and all things tech
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17-01-2013, 14:46
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#1182
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Registered User
Join Date: Feb 2011
Location: Northern and Southern California
Boat: too many
Posts: 3,731
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
Quote:
Originally Posted by diugo
That sure better not be the case. My $700 pair of AGMs only lasted 4.4 years. If these $850 LFPs die in the next three years, I'll be really PO'd.
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Doug,
Here is my bet. In your RV most loads will be well below the C rate the cell's capacity is based on. Between that and the fact that cycle life is based on a cell's ability to hold >80% of rated charge, you are going to be a very happy camper for at least 10 years.
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17-01-2013, 14:50
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#1183
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Registered User
Join Date: Feb 2011
Location: Northern and Southern California
Boat: too many
Posts: 3,731
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
Quote:
Originally Posted by goboatingnow
Why Peukerts is virtually unity !
Dave
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Dave, that is what I thought too, but either the ratings on our cells are very conservative or there is a Peukert effect, not nearly as pronounced as LA, but if nil then my battery at 1365 w-hr now should be fully discharged as it is rated at 1280 w-hr.
I think their ratings are for use in the EV applications, where 3~5 C discharge is common. For our use they appear to have much higher capacities than their ratings.
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17-01-2013, 15:50
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#1184
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Registered User
Join Date: Dec 2012
Location: Yuma, AZ
Boat: USS Asymptote
Posts: 257
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
Quote:
Originally Posted by goboatingnow
Why Peukerts is virtually unity !
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With an internal resistance of 2 millohms per cell? You've got to be kidding.
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17-01-2013, 15:54
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#1185
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Registered User
Join Date: Dec 2012
Location: Yuma, AZ
Boat: USS Asymptote
Posts: 257
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
Quote:
Originally Posted by deckofficer
Doug,
Here is my bet. In your RV most loads will be well below the C rate the cell's capacity is based on. Between that and the fact that cycle life is based on a cell's ability to hold >80% of rated charge, you are going to be a very happy camper for at least 10 years.
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Thanks Bob, I really appreciate your optimism and your willingness to share your Balqon experience and your test results. In a few minutes, I will be pulling the plug on my old AGMs and finally bringing the LFPs online in a big way---microwaving my supper! Wish me luck...
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