Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rating: Thread Rating: 15 votes, 4.47 average. Display Modes
Old 14-02-2010, 07:08   #1
Registered User

Join Date: Jan 2010
Boat: Swan 57
Posts: 59
LiFePO4 Batteries - Okay Tear Me Apart ;-)

The batteries I'm talking about are "LiFePO4" (Lithium-Iron-Phosphate.)

Lithium iron phosphate battery - Wikipedia, the free encyclopedia

Here's one manufacturer:

http://thunder-sky.com/

Here's a couple of American companies selling these batteries... possibly even these exact batteries (at a stiff markup) for marine use:

Genasun
RaceCell

Here's an exporter (I have no affiliation) that will take orders over the 'net and ship them worldwide. Shipping and customs for the 'states adds 10% to the listed price (but is still much cheaper than buying them through the folks above.)

http://www.evcomponents.com/SearchResults.asp?Cat=28

For example, a 600Ah@24v (or, 1200Ah@12v) battery bank could be constructed from 2 sets of 8 cells each (16 total) of this model:

http://www.evcomponents.com/ProductD...TS%2DLFP300AHA
( http://www.thunder-sky.com/pdf/20092131633.pdf )

The arithmetic says (by all means, check and correct me!) that this bank:

...would occupy about 35"x15"x12" (L-W-H) -- ~25% of the volume of the equivalent capacity lead-acid batteries.
...would be 1/3 the weight (340lbs) of the equivalent capacity lead-acid batteries (~950lbs).
...would last 3000+ cycles at ~80% discharge (13x longer cycle-life than the Interstate U2200s I have are rated for).
...would last 5000+ cycles at ~70% discharge (22x longer).
...would charge from 0%->100% on my 160A@24v alternator in about 4 hours. (Yes folks, Peukert no longer applies.)
...would charge faster from an even larger alternator, accepting as much as 1800A@24v(!), to charge completely from 0%->100% in 20 minutes (C3 rating... not C over 3, but C times 3).
...would take about as much current as my wind generator could ever hope to throw at them.
...would cost $5808 ($330x16 = $5280, +10%) from the supplier above... a system cost of ~$10/Ah@24v (~$5/Ah@12v)

Additional benefits:

- Guaranteed by both victron and mastervolt to be 100% compatible with their full range of products, after parameter changes - I asked them last week.
- Environmentally friendly materials, construction
- Completely sealed (no vents, no gassing, no battery boxes)

Possible downsides:

- Non-standard, different, new
- Initial up-front cost. (but lower over-all cost when you factor in the cycle life!)

Other than the usual complaints from the traditionalists and a little more dough in up-front expense, can anyone think of a good reason why shouldn't I turn my back on Lead-Acid batteries, then run away from them screaming?
__________________

__________________
jallum is offline   Reply With Quote
Old 14-02-2010, 07:11   #2
Don't ask if you can't handle it
 
sailorboy1's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: On the boat somewhere
Boat: Hunter 410
Posts: 12,319
seems you gave everything other than a cost comparison between other battery choices.
__________________

__________________
sailorboy1 is offline   Reply With Quote
Old 14-02-2010, 07:19   #3
Registered User
 
Boomerang!'s Avatar

Join Date: Aug 2008
Location: Chesapeake Region of Maryland
Boat: Cal 39, Mark II -
Posts: 22
Images: 4
Not to tear you apart....

But...speaking of life cycles....you might want to find out what percentage of drain their numbers come from. For example, some batteries are tested and can drain as much as 80%...others are tested to 50% drain showing the same numbers of life cycles. But there would be a clear difference....and your individual usage of house banks make all the difference with this calculation. Also, dependent upon your use, starting vs. house, etc....

So, the question is, how are these batteries tested and if these batteries are as good as you say, this info should be available from the manufacturer. I don't want to sit here and type out a whole dissertation on batteries....so....

Nigel Calder's book on boat maintenance might be a good read for you prior to buying....although I am a EE (although I develop software) almost everytime I read something in the book, I learn something new.... Best $50 I ever spent. THere is a whole section devoted to batteries and 12/24/32v systems.... Might want to check it out...
__________________
Charles - S/V Boomerang!
1980 Cal 39, Mark II
St Michaels, MD
Boomerang! is offline   Reply With Quote
Old 14-02-2010, 07:24   #4
Registered User

Join Date: Jan 2010
Boat: Swan 57
Posts: 59
Quote:
Originally Posted by Don Lucas View Post
seems you gave everything other than a cost comparison between other battery choices.
No, I figured out what it'd cost... People's local cost and favorite brand may vary, but lead acid batteries (wet, agm, etc.) are all going to be cheaper up front, by about 4x for super-cheap wet-cells, and 2-3x for nicer agms.

But you have to figure... if Rolls makes a nice wet-cell battery, and they've got a life of only 1300-cycles, you're going to replace them at least 3-5 times before you'd replace these... (depending on how you treat your batteries, of course.) AGMs aren't good for as many cycles and cost more, so the math is actually worse for them.

Over the life of them, the LiFePO4 batteries seem to win handily.
__________________
jallum is offline   Reply With Quote
Old 14-02-2010, 07:29   #5
Registered User

Join Date: Jan 2010
Boat: Swan 57
Posts: 59
Quote:
Originally Posted by Boomerang! View Post
But...speaking of life cycles....you might want to find out what percentage of drain their numbers come from. For example, some batteries are tested and can drain as much as 80%...others are tested to 50% drain showing the same numbers of life cycles. But there would be a clear difference....and your individual usage of house banks make all the difference with this calculation. Also, dependent upon your use, starting vs. house, etc....
In the links I posted, the specs from the manufacturer clearly state that at 80% drain, the cycle-life is 3000. at 70%, it's 5000. (even at 100% it's still 1000. -- better than most any AGM.)

Quote:
Originally Posted by Boomerang! View Post
Nigel Calder's book on boat maintenance might be a good read for you prior to buying....although I am a EE (although I develop software) almost everytime I read something in the book, I learn something new.... Best $50 I ever spent. THere is a whole section devoted to batteries and 12/24/32v systems.... Might want to check it out...
Own it, read it and refer to it constantly. It's a great book... I wholeheartedly endorse it.
__________________
jallum is offline   Reply With Quote
Old 14-02-2010, 07:54   #6
Registered User
 
Boomerang!'s Avatar

Join Date: Aug 2008
Location: Chesapeake Region of Maryland
Boat: Cal 39, Mark II -
Posts: 22
Images: 4
I see that now....must admit, I didn't read the entire spec....sorry about that.

If those stats are real, then sounds like its a buy...
__________________
Charles - S/V Boomerang!
1980 Cal 39, Mark II
St Michaels, MD
Boomerang! is offline   Reply With Quote
Old 14-02-2010, 08:05   #7
Marine Service Provider
 
fastcat435's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Amstelveen Netherlands
Boat: FastCat 445 Green Motion
Posts: 1,649
Images: 10
Send a message via Skype™ to fastcat435
We have used and tested LiFPO batteries for the last 5 years and the result is actually much better than originally estimated , over 3000 cycles down to 85 % ( at 90 % they automatically switch off ) over the first couple of hundred charges the usable amps acually went up to stabilize at 105 % of the original.
We now use the both for propulsion and for the house batteries
The important part is the BMV system to keep them happy
__________________
fastcat435 is offline   Reply With Quote
Old 14-02-2010, 08:07   #8
Commercial Member
 
CharlieJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: St. Petersburg, FL
Boat: Gulfstar Long Range Trawler; 53'; BearBoat
Posts: 836
Jallum-Great post!

These batteries exhibit some very exciting potential for the power hungry marine market. But...

My reservations are:
1. I personally have been burned too many times when I bought the "first of type" model.
2. Who warrants the batteries and for how long?
3. What is the industry (any industry's) experience with these batteries?
4. Made in China.

Don't get me wrong, I am anything but a Luddite and I will certainly watch further development of these batteries and their penetration into various markets very closely.
__________________
Charlie Johnson
JTB Marine Corporation
"The Devil is in the details and so is salvation."
CharlieJ is online now   Reply With Quote
Old 14-02-2010, 08:17   #9
Marine Service Provider
 
fastcat435's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Amstelveen Netherlands
Boat: FastCat 445 Green Motion
Posts: 1,649
Images: 10
Send a message via Skype™ to fastcat435
Lithium Ion LiFpo are being used by most new commercial aircraft as emergency backup to start engines in the air and for Radio use, they are FAA approved ( SAFT ) and are used already for many years, you probably have a cheap version in your laptop and cell phone ( not LifPO and they work well for a few years , these batteries have a design life of 300 to 500 cycles , that has to do with the technology behind it , however the latest versions can last up to 5000 cycles
__________________
fastcat435 is offline   Reply With Quote
Old 14-02-2010, 08:20   #10
Registered User

Join Date: Jan 2010
Boat: Swan 57
Posts: 59
Quote:
Originally Posted by CharlieJ View Post
Jallum-Great post!
Thanks!

Quote:
1. I personally have been burned too many times when I bought the "first of type" model.
Fair enough. These aren't new, though. The DIY electric car people have been using them for years -- we're just slow to the game.

Quote:
2. Who warrants the batteries and for how long?
No mention in the specs. I've sent them an email, and we'll see what they say. I'll make sure to post their reply.

Quote:
3. What is the industry (any industry's) experience with these batteries?
The EV-car people seem to love them. They're used in electric busses. They're also starting to peek into the marine market, e.g. Genasun and RaceCell.

Quote:
4. Made in China.
Point taken, but umm... What isn't these days?

Quote:
Don't get me wrong, I am anything but a Luddite and I will certainly watch further development of these batteries and their penetration into various markets very closely.
I'm right there with you, which is why I thought it best to bring it here for some intelligent discussion. I don't mind spending money, but I hate wasting it -- I'm sure you're the same way.
__________________
jallum is offline   Reply With Quote
Old 14-02-2010, 10:09   #11
Registered User

Join Date: Jan 2010
Boat: Swan 57
Posts: 59
Golf cart batteries are false economy.

So, it looks like I overstated the volume and weight savings a little bit. Going with (the above mentioned) LiFePO4 batteries, you'll only save between 30-70% space by volume, and shed 45-60% of the weight vs. lead acid. When I run the math, it also turns out that I was being way too kind to the lead acid batteries... the up-front cost of the LiFePO4 batteries in question is only 2x more expensive than for high-end AGMs, and 3x more expensive than golf-cart batteries. (I had said 4-5x.)

Disregarding the weight, space, charging and low-self-discharging advantages of these LiFePO4s... cost-per-cycle wise, they still kick the crap out of lead acid, coming in at anywhere between 3-9 times cheaper over the life of the battery, depending on how little you choose to spend up front. The huge takeaway from this exercise is no matter what kind of battery you buy, the less you spend up front, the more you will spend over time.

So, without further ado... I'll show my homework. For each type/brand of battery, I figured out the volume, weight, and cycle-life (@50% discharge) of a bank of roughly 600Ah@24v. For the bottom line, I divided each value by the total number of Ah@24v in the bank, yielding a value-per-Ah (for those of you with 12v problems, divide by two again.) I then computed the actual cost of each type of battery per 1000 cycles. (Guess which won easily?)


675Ah@24v built with 12 Trojan TS-105 (3 x 4) -- typical high-end golf-cart batteries.
http://www.trojanbattery.com/pdf/Prt...Guide_0909.pdf
63"x14"x11" -- 9702cu-in (batteries only, no battery boxes which would be required.)
744lbs (12x63lbs)
<300 cycles (@50%)
~$1920 ($160ea) from Trojan Battery T105 (225AH) -- other vendors may vary

bottom line:
per Ah@24v: 14.37cu-in / 1.1lbs / $2.84
per 1000 cycles: $6400


670Ah@24v built with 8 FullRiver DC335-6 AGMs (2 x 4)
specs: http://www.fullriverdcbattery.com/DC335_6.pdf
47"x14"x14" -- 9202cu-in
840lbs (8 x 106lbs)
~800 cycles (@50%) -- estimated
$2985 ($373ea) from Southeast Marine Services :: Absorbed Glass Mat (AGM) Batteries :: Full River Absorbed Glass Mat (AGM) Batteries -- other vendors may vary

bottom line:
per Ah@24v: 13.73cu-in / 1.25lbs / $4.45
per 1000 cycles: $3731


600Ah@24v built with 8 LifeLine GPL-6CT AGMs (2 x 4)
specs: Lifeline Batteries - Marine & RV Deep Cycle Batteries
42"x14"x13" -- 7644cu-in
720lbs (8 x 90)
1100 cycles (@50%)
$2607 ($326ea) from Lifeline GPL-6CT Deep Cycle Marine & RV Battery -- other vendors may vary

bottom line:
per Ah@24v: 12.74cu-in / 1.2lbs / $4.35
per 1000 cycles: $2370


600Ah@24v built with 8 Rolls NS 305 wet-cells (2 x 4) -- these are the most compact, long-lived wet cells I could find:
http://www.rolls-europe.com/PDF/ns305.pdf
49"x15"x14" -- 10290cu-in (batteries only, no battery boxes which would be required.)
872lbs (8x109lbs)
1300 cycles (@50%)
~$2800 ($349ea) from Staab Battery: Rolls Surrette Batteries, Marine Starting and Deep Cycle -- other vendors may vary

bottom line:
per Ah@24v: 17.15 cu-in / 1.45lbs / $4.60
per 1000 cycles: $2154


600Ah@24v built with 16 ThunderSky LiFePO4 (2 x 8):
specs: http://www.thunder-sky.com/pdf/20092131633.pdf
35"x15"x12" -- 6300cu-in (no battery boxes required.)
337lbs (16x21lbs)
>8000 cycles (@50%)
$5808 ($330x16 = $5280, +10%)

bottom line:
per Ah@24v: 10.5cu-in / 0.56lbs / $9.60
per 1000 cycles: $726


Anyone see any problems with my math or methodology? Oh, and please oh please, if you don't see your favorite flavor here, take a minute, do the math and post it.
__________________
jallum is offline   Reply With Quote
Old 14-02-2010, 11:18   #12
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Interesting comparisons. And, on paper, they seem valid. But, in the real world, not so much.

Look around you at the boats in your marina...the sailboats. What percentage of them go out at all and how often? How long do they stay out? Overnighters on weekends? One two-week cruise a year, and a bunch of weekenders?

The plain truth is that unless you're an active liveaboard cruiser for several months a year at least, the figures don't add up. Hey, when you're at dockside or on a mooring, a single 100AH or 200AH battery bank should take care of your needs very nicely. With a battery charger or solar panel or wind generator to keep the batteries up, it really isn't necessary to have a 400 or 800 or 1200AH house battery bank. All that reserve power just goes to waste. Unless you're actively cruising.

I have a friend in the business (also) who's come to the conclusion that for the majority of boats, including power boats, in most marinas the best setup would be to have a set of gelled batteries and a small battery charger for the house bank, and a starting battery with a small solar panel for the engine(s).

Most boats which are not actively liveaboard cruisers may spend 5-10% of the time actually out and on anchor. Given the upper end of this range, that's some 36 nights per year...and that's a generous estimate. At this rate, 1,000 cycles to 50% would take about 28 years!!

Now, for really active full-time cruisers who mostly avoid marinas and spend much or most of their time on the hook, some of the calculations are really interesting. However, the figures IMHO tend to overstate the advantages of the money-up-front line of thought.

Six-volt golf-cart batteries of good quality can be had for about half the price used for T-105's in the above examples. You can build a 675AH @ 12 volt battery bank for under $500. Take care of the batteries and they will last you 4 to 7 years (that's what most cruisers report). Say 5 years. That's $100 per year. Total. Plus the musclepower required to change them out.

Many cruisers will find that kind of expenditure preferable to shelling out several thousand dollars for batteries which MAY last them twice or three times as long.

'Course the problem with this math is what to do with the other $2,408 you saved by not going with the LiFEPO4's ??

Bill
__________________
btrayfors is offline   Reply With Quote
Old 14-02-2010, 11:27   #13
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29 49.16 N 82 25.82 W
Boat: Pearson 422
Posts: 12,383
Think Bill hit the nail on the head. For the great majority of the boats out there that seldom leave the dock and when they do they are out for a weekend or so the investment doesn't make sense.

So, until I'm ready to cut the lines long term will stick with plain old lead acid. Maybe by the time I do take off the cost on the new batteries will be down a bit.
__________________
The water is always bluer on the other side of the ocean.
skipmac is online now   Reply With Quote
Old 14-02-2010, 11:33   #14
Vendor
 
witzgall's Avatar

Join Date: Oct 2006
Location: Eastern Shore, MD
Boat: Camper Nicholson 44 Ketch
Posts: 1,775
I built a 24v, 40ah battery from Sky Energy LIFEPO4 cells this summer. The cells came from EV Components, and I sourced the charger and BMS from a Hong Kong supplier directly. It is powering our Torqueedo dingy motor.

So far, so good. The pack weighs 26 lbs, in one of the orange waterproof boxes. Compare that with a 12v, 80ah Lead Acid battery, at what, perhaps 70lbs?

Chris
__________________
witzgall is offline   Reply With Quote
Old 14-02-2010, 11:40   #15
Marine Service Provider
 
fastcat435's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Amstelveen Netherlands
Boat: FastCat 445 Green Motion
Posts: 1,649
Images: 10
Send a message via Skype™ to fastcat435
You did not overstate the volume and weight saving , not even a bit
Keep in mind that LifePO can be drained with out after effects to 80 or even 90 % drained
\While the average dep cycle battery can only be drained to 50 % and getting 1000 cycles out of a lead acid battery while drainig it to 50 % is almost impossible , count with 500 cycles max or 4 years whatever comes first
On the Green Motion cat we have 360 kilo ( 800 LBS ) of Lithium Batteries (34 Kw usable )on board and for the same KWh of Lead acid we would need 1547 kilo,s of lead acid or 1187 more kilo's ( 2615 Lbs) In this case the Lithium batteries only save about 75 % and for the volume the saving is 1102 liters or 306 us gallons again in the region of 75 %
__________________

__________________
fastcat435 is offline   Reply With Quote
Reply

Tags
lifepo4, battery

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:23.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.