Saturday, August 31, 2013

[Electric Boats] Battery selection

 

I recently purchased a nice 14 ' English built fiberglass sailboat weighing perhaps 300 lb. and a 50 lb. thrust Minnkota trolling motor. Please comment on having 2 smaller marine batteries as opposed to 1 larger battery.  Also, I am seeing references to Group 34 batteries and Group 27 batteries.  What does "Group" mean? Also, I would appreciate comments about the Optima blue top line of batteries. I am not going to be sailing the boat but rather puttering around on the small lakes here in central Colorado. Most of the lakes here are reservoirs for all kinds of uses, including drinking water, so most prohibit gasoline outboard motors.   Thanks,  Dell

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Friday, August 30, 2013

[Electric Boats] Hello and Greetings

 

Greetings everyone.
I have been on the list here for a week or so just lurking and trying to absorb. I have a 1960 30' Alden sailboat who's aging and unreliable Atomic 4 just died. Instead of rebuilding it yet again I have decided to re-power using electric. I am leaning toward the Thunderstuck sailboat package with the 2:1 gear reduction.
If anyone has any questions comments or input feel free to let me know.
I am currently just now ripping the old engine out and I want to get the interior painted before I start putting in batteries and the motor, so I have until next spring to get everything figured out.
Thanks for the great forum to learn from others and the knowledge others have posted after so much hard work....
I look forward to learning much more from all of you...
Bryan

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Re: [Electric Boats] Care and feeding of LiFePo batteries?

 

I'm using a Mastervolt Li ion Ultra, untill now it's doing what it's supposed to. I charge it with a mastervolt charger which is programmed at the correct voltages to start and stop charging. I have shore power connected all times when docked, however I wonder if this is wise to do. Any tips?

Regarding the 50lbs saving on the Dreamliner, fleet wide a weight saving of 50 lbs will reduce fuel cost with approximately $1,000,000.- (and co2 emissions), so indeed, Bravo Boeing!

--- In electricboats@yahoogroups.com, Robert Lemke <robert-lemke@...> wrote:
>
> Dave,
>
>   Which cells are you using? I use Winston and set my low voltage alarm at 2.8 volts. I paid $1.10 per amp from Balqon. 
>
> Bob
>
>
> ________________________________
> From: Dave Steere <dcsteere@...>
> To: electricboats@yahoogroups.com
> Sent: Wednesday, August 28, 2013 7:37 PM
> Subject: Re: [Electric Boats] Care and feeding of LiFePo batteries?
>
>
>
>
>
>
>
> Li dead voltage (empty of charge) is around 2.6VDC per cell.  Full charge is around 3.35V (after settling).  You can charge them to as high as 3.7 (some references say 3.8V) without damaging, but they settle for a period of hours to around 3.35V per cell when full.  I have no idea where you got 14V and 16V.  
>
> Likewise, if you discharge them to around 2.6V, they will very likely rejuvenate a bit in a matter of hours (or maybe a day) and you will need to again discharge to get the battery down to empty.  You can buy lithium cells (LiFEPO4) for around $1.25 per Amp Hour.  For example, my EV has 36 cells, each with 120 AH capacity.  Thus my "full tank" voltage is around 121V.  That means I have around 14KW continuous power available.  My pack can deliver much higher current for very brief acceleration, on the order of 600-650 A, but you don't want to do that for more than a few seconds if you want to avoid having a dead duck for a battery pack.  Total price for my pack is around $5400.
>
>   I don't know about trickle charging them, but I do know that just reaching full voltage alone is sometimes not entirely enough.  A short time of constant current charging (after getting there with constant voltage charging) is a good idea when topping off, but one has to be very careful about over charging.  I also can't give you first hand experience with number of cycles.  My EV has been operational for about 14 mos. now and it's looking like around 5 or maybe 6 cells need replacing already.  It's a big disappointment and I don't know yet why this has happened.  I have never had any cell above about 3.8V or below about 2.3V.
>
>   Testing is still in progress, and I'm not real happy about replacing just a few batteries in the pack, knowing that I'll never achieve really good balance with some  that came from completely different production lots.   If you're not familiar with battery balancing, there is lots and lots of on line information about this.  Some of it is pure BS and some is probably pretty accurate.  One can either "bottom balance" or "top balance" and there's lots of controversy about which is the preferable method.  But lithium batteries are much more sensitive about balancing than any form of lead acid, whether it be AGM, flooded, or gel.  One more consideration (and this one is kind of controversial too) is the need for a BMS (battery management system).  Lithium is much more in need of such a capability than lead acid.  Lots  of info about this on the various blogs and other web sites.  I won't enter an opinion on these matters at the risk of stirring
> up a hornet's nest!
>
> Dave
>
>
>
>
> On Wed, Aug 28, 2013 at 3:33 PM, oak <oak_box@...> wrote:
>
>
> > 
> >I was concerned to see the statement:
> >"Also they were trickle charged at all times, another no no".
> >
> >
> >Does that apply to LiFePo batteries?
> >Can anyone provide a summary of what the do's and don'ts are for these batteries?
> >
> >
> >This is probably asking wayyyy too much, but wouldn't it be neat if we could make a matrix of FLA, AGM, LiFePo, and show the various properties of each in a side by side arrangement?
> >
> >
> >I'd really like to see this for a 12V battery:
> >
> >
> >PropertyFLAAGMLiFePo
> >"dead" voltage9V9V14V
> >"max" charge v14V14V16V
> >Trickle ch maintain?YesYesno(?)
> >Average cycle life200?300?1200?
> >Average cost (100Ah)$80$180$500+(?)
> >Mainthigh - water/acidnonenone
> >BMSnonostrongly recommended
> >recovery when dead?yesyesno
> >
> >
> >Any other traits we can add to this, or other things to be aware of??
> >Note:  by "recovery" - I heard that a Li battery is very good for holding it's voltage until it's dead.   But once it's dead - it's DEAD.  You can't wait for a few minutes and use it again lightly on the "recovery" like you can for FLA's.
> >
> >
> >John
> >
> >
> >
> >________________________________
> > From: Steve Dolan <sdolan@...>
> >To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
> >Sent: Wednesday, August 28, 2013 7:10 AM
> >Subject: RE: [Electric Boats] Re: AGM Batteries?
> >
> >
> >
> > 
> >Boeing’s Dreamliner was an “international”
> plane built by contractors all over the world from many countries. As with
> anything like this it was a coordination nightmare. My understanding of this “event”
> was the problem was in the BMS system program not the batteries them selves.
> The system was spec’d to be at 100% charged at all times, something that
> has been determined to be on the ragged edge of theses batteries, you never
> want to overcharge them and this is what happened. They simply where over
> charged causing them to overheat. Also they where trickle charged at all times,
> another no no. I believe there were some issues with the BMS circuit boards as
> well on the bats. As for the chemistry, all it takes is someone to push hard
> from a major supplier from a country that planed to buy the Dreamliner who had
> an interest in sales first to talk someone into their product.   
> > 
> >Steve in Solomons MD
> > 
> >But sport planes don't carry hundreds of passengers. If the amount of
> weight difference between LiFePO and LiCo is that critical, I am sure that it could
> be made up by creating carbon fiber drink carts instead of aluminum ones ;-) or
> reducing the baggage allowance per passenger accordingly. 
> >The Dreamliner packs a total of about 5kwh of lithium batteries. Eric's
> 8kwh pack weighs 200lbs. So how much weight has been saved by using LiCo?
> >Using your own 25% lighter than LiFePO figure, that would amount to a
> whopping 50lbs. The maximum take-off weight of the Dreamliner is about
> 500,000lbs. So we're talking a 1% of 1% weight savings by using LiCo.
>  Bravo Boeing. 
> >
> >
> >
> >
> >
> >
> >
> >
>
>
> --
> All the best,
> Dave Steere
> dcsteere@...
> 850-234-2540  office
> 850-319-6010  cell phone
>

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Thursday, August 29, 2013

[Electric Boats] i4 Electric Boat

 


Platium i4 Electric Boat - $11500 (Stoney Creek Ontario)
New boat was not on water yet top speed 25 miles hour . Pleasure fishing for the whole family to enjoy. It comes with Bimini cover plus tarp cover ,Trailer plus remote control stereo. Top retail $20,000.00. Contact Frank. - this is a fully loaded boat to enjoy. . Private Sale TO ENJOY THIS SUMMER. MAKE AN OFFER This was contest winner. For more information on boat click on web Platinum i4 Electric. Home Catalogue New Boats New Open Boats Platinum i4 electric Info: Your browser does not accept cookies. To put products into your cart and purchase them you need to enable cookies.
OPEN FOR OFFERS

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[Electric Boats] i4 Electric Boat

 


Platium i4 Electric Boat - $11500 (Stoney Creek Ontario)
New boat was not on water yet top speed 25 miles hour . Pleasure fishing for the whole family to enjoy. It comes with Bimini cover plus tarp cover ,Trailer plus remote control stereo. Top retail $20,000.00. Contact Frank. - this is a fully loaded boat to enjoy. . Private Sale TO ENJOY THIS SUMMER. MAKE AN OFFER This was contest winner. For more information on boat click on web Platinum i4 Electric. Home Catalogue New Boats New Open Boats Platinum i4 electric Info: Your browser does not accept cookies. To put products into your cart and purchase them you need to enable cookies.
OPEN FOR OFFERS

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Re: [Electric Boats] Care and feeding of LiFePo batteries?

 

Mine are Real Force 120 AH.  I bought them from Lithium Solutions in Salt Lake City.  Not sure I would recommend them, given my experience with some of them pooping out so earlyinlife.   from my research I am led to believe that CALB is the superior name in lithium batteries.

On Aug 28, 2013 9:48 PM, "Robert Lemke" <robert-lemke@att.net> wrote:
 

Dave,

  Which cells are you using? I use Winston and set my low voltage alarm at 2.8 volts. I paid $1.10 per amp from Balqon. 

Bob


From: Dave Steere <dcsteere@dcsteere.com>
To: electricboats@yahoogroups.com
Sent: Wednesday, August 28, 2013 7:37 PM
Subject: Re: [Electric Boats] Care and feeding of LiFePo batteries?



Li dead voltage (empty of charge) is around 2.6VDC per cell.  Full charge is around 3.35V (after settling).  You can charge them to as high as 3.7 (some references say 3.8V) without damaging, but they settle for a period of hours to around 3.35V per cell when full.  I have no idea where you got 14V and 16V.  

Likewise, if you discharge them to around 2.6V, they will very likely rejuvenate a bit in a matter of hours (or maybe a day) and you will need to again discharge to get the battery down to empty.  You can buy lithium cells (LiFEPO4) for around $1.25 per Amp Hour.  For example, my EV has 36 cells, each with 120 AH capacity.  Thus my "full tank" voltage is around 121V.  That means I have around 14KW continuous power available.  My pack can deliver much higher current for very brief acceleration, on the order of 600-650 A, but you don't want to do that for more than a few seconds if you want to avoid having a dead duck for a battery pack.  Total price for my pack is around $5400.

  I don't know about trickle charging them, but I do know that just reaching full voltage alone is sometimes not entirely enough.  A short time of constant current charging (after getting there with constant voltage charging) is a good idea when topping off, but one has to be very careful about over charging.  I also can't give you first hand experience with number of cycles.  My EV has been operational for about 14 mos. now and it's looking like around 5 or maybe 6 cells need replacing already.  It's a big disappointment and I don't know yet why this has happened.  I have never had any cell above about 3.8V or below about 2.3V.

  Testing is still in progress, and I'm not real happy about replacing just a few batteries in the pack, knowing that I'll never achieve really good balance with some  that came from completely different production lots.   If you're not familiar with battery balancing, there is lots and lots of on line information about this.  Some of it is pure BS and some is probably pretty accurate.  One can either "bottom balance" or "top balance" and there's lots of controversy about which is the preferable method.  But lithium batteries are much more sensitive about balancing than any form of lead acid, whether it be AGM, flooded, or gel.  One more consideration (and this one is kind of controversial too) is the need for a BMS (battery management system).  Lithium is much more in need of such a capability than lead acid.  Lots  of info about this on the various blogs and other web sites.  I won't enter an opinion on these matters at the risk of stirring up a hornet's nest!

Dave


On Wed, Aug 28, 2013 at 3:33 PM, oak <oak_box@yahoo.com> wrote:
 
I was concerned to see the statement:
"Also they were trickle charged at all times, another no no".

Does that apply to LiFePo batteries?
Can anyone provide a summary of what the do's and don'ts are for these batteries?

This is probably asking wayyyy too much, but wouldn't it be neat if we could make a matrix of FLA, AGM, LiFePo, and show the various properties of each in a side by side arrangement?

I'd really like to see this for a 12V battery:

Property FLA AGM LiFePo
"dead" voltage 9V 9V 14V
"max" charge v 14V 14V 16V
Trickle ch maintain? Yes Yes no(?)
Average cycle life 200? 300? 1200?
Average cost (100Ah) $80 $180 $500+(?)
Maint high - water/acid none none
BMS no no strongly recommended
recovery when dead? yes yes no

Any other traits we can add to this, or other things to be aware of??
Note:  by "recovery" - I heard that a Li battery is very good for holding it's voltage until it's dead.   But once it's dead - it's DEAD.  You can't wait for a few minutes and use it again lightly on the "recovery" like you can for FLA's.

John


From: Steve Dolan <sdolan@scannersllc.com>
To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
Sent: Wednesday, August 28, 2013 7:10 AM
Subject: RE: [Electric Boats] Re: AGM Batteries?

 
Boeing's Dreamliner was an "international" plane built by contractors all over the world from many countries. As with anything like this it was a coordination nightmare. My understanding of this "event" was the problem was in the BMS system program not the batteries them selves. The system was spec'd to be at 100% charged at all times, something that has been determined to be on the ragged edge of theses batteries, you never want to overcharge them and this is what happened. They simply where over charged causing them to overheat. Also they where trickle charged at all times, another no no. I believe there were some issues with the BMS circuit boards as well on the bats. As for the chemistry, all it takes is someone to push hard from a major supplier from a country that planed to buy the Dreamliner who had an interest in sales first to talk someone into their product.   
 
Steve in Solomons MD
 
But sport planes don't carry hundreds of passengers. If the amount of weight difference between LiFePO and LiCo is that critical, I am sure that it could be made up by creating carbon fiber drink carts instead of aluminum ones ;-) or reducing the baggage allowance per passenger accordingly. 
The Dreamliner packs a total of about 5kwh of lithium batteries. Eric's 8kwh pack weighs 200lbs. So how much weight has been saved by using LiCo?
Using your own 25% lighter than LiFePO figure, that would amount to a whopping 50lbs. The maximum take-off weight of the Dreamliner is about 500,000lbs. So we're talking a 1% of 1% weight savings by using LiCo.  Bravo Boeing. 









--
All the best,
Dave Steere
dcsteere@dcsteere.com
850-234-2540  office
850-319-6010  cell phone




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Re: [Electric Boats] FYI - Methanol fuel cell battery charging

 

- the most interesting part of the off-site thread was the commercialisation (finally) of Nickel-Iron batteries. they're not delicate, don't have any of the bad habits of most other types, love hard work, no memory, no environmental issues, no real reason they should ever die (if watered regularly).

- they're also a quarter of the weight of agm's, and hopefully mass production etc will get the price down as they look like around 5 times the cost of decent agm's........ but as someone will tell me, if you factor in the d.o.d. and life cycles etc etc they are probably not too far away from agm's?


On 29 August 2013 01:20, Nick <chernikit@gmail.com> wrote:
 

I can't wait for the day a fuelled charger becomes economically feasible for direct boat propulsion or battery replenishment. A clever fellow in these parts actually put together a hydrogen one of his own design a few years ago and powered a 6 metre sailboat with it. I visited with him to discuss, and it still had some rough edges at the time.

 

http://www.canada.com/story_print.html?id=dc595066-34ef-4dc6-85ac-d9fada7549cb&sponsor=

 

And.. looks like he's still in business:

 

http://www.agofuelcells.com/index.html

 

Will have to go have another look.

 

- Nick

 

 

 

 

From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of Sally Reuther
Sent: Wednesday, August 28, 2013 9:58 AM
To: electricboats
Subject: Re: [Electric Boats] FYI - Methanol fuel cell battery charging

 

 

We've seen these EFOY units and talked with the company - we even had one to try out for a while. They are mainly for 12volt, although they offer a 24volt last I checked. For electric propulsion they can't offer much in the way of charging because they just aren't big enough to handle the larger amperage loads demanded. We are headed to IBEX in a couple of weeks and I'll be interested to see if there is anything new with this. I'll report back if I find anything new and exciting.

Sally Reuther

Annapolis Hybrid Marine

 

On Tue, Aug 27, 2013 at 2:14 PM, Nick <chernikit@gmail.com> wrote:

 

Just an FYI - recently came across this Pacific Yachting article (Dec 2012) on some in-boat trials of a methanol fuel cell for battery charging produced by SFC (German company near Munich).

 

http://www.standard-hydrogen.com/PY_DEC12_EFOY.pdf

 

http://www.sfc.com/en

 

Looks expensive, but might be the just the right thing for some people.

 

- Nick

 




--

Phone;  (+44)  02895 811251  -  Mobile;  (+44) 07427 696 796  -  Fax;  (+44) 0871 9898296
Company number;   NI067673

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Wednesday, August 28, 2013

Re: [Electric Boats] Care and feeding of LiFePo batteries?

 

Dave,

  Which cells are you using? I use Winston and set my low voltage alarm at 2.8 volts. I paid $1.10 per amp from Balqon. 

Bob


From: Dave Steere <dcsteere@dcsteere.com>
To: electricboats@yahoogroups.com
Sent: Wednesday, August 28, 2013 7:37 PM
Subject: Re: [Electric Boats] Care and feeding of LiFePo batteries?



Li dead voltage (empty of charge) is around 2.6VDC per cell.  Full charge is around 3.35V (after settling).  You can charge them to as high as 3.7 (some references say 3.8V) without damaging, but they settle for a period of hours to around 3.35V per cell when full.  I have no idea where you got 14V and 16V.  

Likewise, if you discharge them to around 2.6V, they will very likely rejuvenate a bit in a matter of hours (or maybe a day) and you will need to again discharge to get the battery down to empty.  You can buy lithium cells (LiFEPO4) for around $1.25 per Amp Hour.  For example, my EV has 36 cells, each with 120 AH capacity.  Thus my "full tank" voltage is around 121V.  That means I have around 14KW continuous power available.  My pack can deliver much higher current for very brief acceleration, on the order of 600-650 A, but you don't want to do that for more than a few seconds if you want to avoid having a dead duck for a battery pack.  Total price for my pack is around $5400.

  I don't know about trickle charging them, but I do know that just reaching full voltage alone is sometimes not entirely enough.  A short time of constant current charging (after getting there with constant voltage charging) is a good idea when topping off, but one has to be very careful about over charging.  I also can't give you first hand experience with number of cycles.  My EV has been operational for about 14 mos. now and it's looking like around 5 or maybe 6 cells need replacing already.  It's a big disappointment and I don't know yet why this has happened.  I have never had any cell above about 3.8V or below about 2.3V.

  Testing is still in progress, and I'm not real happy about replacing just a few batteries in the pack, knowing that I'll never achieve really good balance with some  that came from completely different production lots.   If you're not familiar with battery balancing, there is lots and lots of on line information about this.  Some of it is pure BS and some is probably pretty accurate.  One can either "bottom balance" or "top balance" and there's lots of controversy about which is the preferable method.  But lithium batteries are much more sensitive about balancing than any form of lead acid, whether it be AGM, flooded, or gel.  One more consideration (and this one is kind of controversial too) is the need for a BMS (battery management system).  Lithium is much more in need of such a capability than lead acid.  Lots  of info about this on the various blogs and other web sites.  I won't enter an opinion on these matters at the risk of stirring up a hornet's nest!

Dave


On Wed, Aug 28, 2013 at 3:33 PM, oak <oak_box@yahoo.com> wrote:
 
I was concerned to see the statement:
"Also they were trickle charged at all times, another no no".

Does that apply to LiFePo batteries?
Can anyone provide a summary of what the do's and don'ts are for these batteries?

This is probably asking wayyyy too much, but wouldn't it be neat if we could make a matrix of FLA, AGM, LiFePo, and show the various properties of each in a side by side arrangement?

I'd really like to see this for a 12V battery:

Property FLA AGM LiFePo
"dead" voltage 9V 9V 14V
"max" charge v 14V 14V 16V
Trickle ch maintain? Yes Yes no(?)
Average cycle life 200? 300? 1200?
Average cost (100Ah) $80 $180 $500+(?)
Maint high - water/acid none none
BMS no no strongly recommended
recovery when dead? yes yes no

Any other traits we can add to this, or other things to be aware of??
Note:  by "recovery" - I heard that a Li battery is very good for holding it's voltage until it's dead.   But once it's dead - it's DEAD.  You can't wait for a few minutes and use it again lightly on the "recovery" like you can for FLA's.

John


From: Steve Dolan <sdolan@scannersllc.com>
To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
Sent: Wednesday, August 28, 2013 7:10 AM
Subject: RE: [Electric Boats] Re: AGM Batteries?

 
Boeing's Dreamliner was an "international" plane built by contractors all over the world from many countries. As with anything like this it was a coordination nightmare. My understanding of this "event" was the problem was in the BMS system program not the batteries them selves. The system was spec'd to be at 100% charged at all times, something that has been determined to be on the ragged edge of theses batteries, you never want to overcharge them and this is what happened. They simply where over charged causing them to overheat. Also they where trickle charged at all times, another no no. I believe there were some issues with the BMS circuit boards as well on the bats. As for the chemistry, all it takes is someone to push hard from a major supplier from a country that planed to buy the Dreamliner who had an interest in sales first to talk someone into their product.   
 
Steve in Solomons MD
 
But sport planes don't carry hundreds of passengers. If the amount of weight difference between LiFePO and LiCo is that critical, I am sure that it could be made up by creating carbon fiber drink carts instead of aluminum ones ;-) or reducing the baggage allowance per passenger accordingly. 
The Dreamliner packs a total of about 5kwh of lithium batteries. Eric's 8kwh pack weighs 200lbs. So how much weight has been saved by using LiCo?
Using your own 25% lighter than LiFePO figure, that would amount to a whopping 50lbs. The maximum take-off weight of the Dreamliner is about 500,000lbs. So we're talking a 1% of 1% weight savings by using LiCo.  Bravo Boeing. 









--
All the best,
Dave Steere
dcsteere@dcsteere.com
850-234-2540  office
850-319-6010  cell phone




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Re: [Electric Boats] Care and feeding of LiFePo batteries?

 

Li dead voltage (empty of charge) is around 2.6VDC per cell.  Full charge is around 3.35V (after settling).  You can charge them to as high as 3.7 (some references say 3.8V) without damaging, but they settle for a period of hours to around 3.35V per cell when full.  I have no idea where you got 14V and 16V.  

Likewise, if you discharge them to around 2.6V, they will very likely rejuvenate a bit in a matter of hours (or maybe a day) and you will need to again discharge to get the battery down to empty.  You can buy lithium cells (LiFEPO4) for around $1.25 per Amp Hour.  For example, my EV has 36 cells, each with 120 AH capacity.  Thus my "full tank" voltage is around 121V.  That means I have around 14KW continuous power available.  My pack can deliver much higher current for very brief acceleration, on the order of 600-650 A, but you don't want to do that for more than a few seconds if you want to avoid having a dead duck for a battery pack.  Total price for my pack is around $5400.

  I don't know about trickle charging them, but I do know that just reaching full voltage alone is sometimes not entirely enough.  A short time of constant current charging (after getting there with constant voltage charging) is a good idea when topping off, but one has to be very careful about over charging.  I also can't give you first hand experience with number of cycles.  My EV has been operational for about 14 mos. now and it's looking like around 5 or maybe 6 cells need replacing already.  It's a big disappointment and I don't know yet why this has happened.  I have never had any cell above about 3.8V or below about 2.3V.

  Testing is still in progress, and I'm not real happy about replacing just a few batteries in the pack, knowing that I'll never achieve really good balance with some  that came from completely different production lots.   If you're not familiar with battery balancing, there is lots and lots of on line information about this.  Some of it is pure BS and some is probably pretty accurate.  One can either "bottom balance" or "top balance" and there's lots of controversy about which is the preferable method.  But lithium batteries are much more sensitive about balancing than any form of lead acid, whether it be AGM, flooded, or gel.  One more consideration (and this one is kind of controversial too) is the need for a BMS (battery management system).  Lithium is much more in need of such a capability than lead acid.  Lots  of info about this on the various blogs and other web sites.  I won't enter an opinion on these matters at the risk of stirring up a hornet's nest!

Dave


On Wed, Aug 28, 2013 at 3:33 PM, oak <oak_box@yahoo.com> wrote:
 

I was concerned to see the statement:
"Also they were trickle charged at all times, another no no".

Does that apply to LiFePo batteries?
Can anyone provide a summary of what the do's and don'ts are for these batteries?

This is probably asking wayyyy too much, but wouldn't it be neat if we could make a matrix of FLA, AGM, LiFePo, and show the various properties of each in a side by side arrangement?

I'd really like to see this for a 12V battery:

Property FLA AGM LiFePo
"dead" voltage 9V 9V 14V
"max" charge v 14V 14V 16V
Trickle ch maintain? Yes Yes no(?)
Average cycle life 200? 300? 1200?
Average cost (100Ah) $80 $180 $500+(?)
Maint high - water/acid none none
BMS no no strongly recommended
recovery when dead? yes yes no

Any other traits we can add to this, or other things to be aware of??
Note:  by "recovery" - I heard that a Li battery is very good for holding it's voltage until it's dead.   But once it's dead - it's DEAD.  You can't wait for a few minutes and use it again lightly on the "recovery" like you can for FLA's.

John


From: Steve Dolan <sdolan@scannersllc.com>
To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
Sent: Wednesday, August 28, 2013 7:10 AM
Subject: RE: [Electric Boats] Re: AGM Batteries?

 
Boeing's Dreamliner was an "international" plane built by contractors all over the world from many countries. As with anything like this it was a coordination nightmare. My understanding of this "event" was the problem was in the BMS system program not the batteries them selves. The system was spec'd to be at 100% charged at all times, something that has been determined to be on the ragged edge of theses batteries, you never want to overcharge them and this is what happened. They simply where over charged causing them to overheat. Also they where trickle charged at all times, another no no. I believe there were some issues with the BMS circuit boards as well on the bats. As for the chemistry, all it takes is someone to push hard from a major supplier from a country that planed to buy the Dreamliner who had an interest in sales first to talk someone into their product.   
 
Steve in Solomons MD
 
But sport planes don't carry hundreds of passengers. If the amount of weight difference between LiFePO and LiCo is that critical, I am sure that it could be made up by creating carbon fiber drink carts instead of aluminum ones ;-) or reducing the baggage allowance per passenger accordingly. 
The Dreamliner packs a total of about 5kwh of lithium batteries. Eric's 8kwh pack weighs 200lbs. So how much weight has been saved by using LiCo?
Using your own 25% lighter than LiFePO figure, that would amount to a whopping 50lbs. The maximum take-off weight of the Dreamliner is about 500,000lbs. So we're talking a 1% of 1% weight savings by using LiCo.  Bravo Boeing. 









--
All the best,
Dave Steere
dcsteere@dcsteere.com
850-234-2540  office
850-319-6010  cell phone

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