Lithium Batteries (for the rest of us)

[hellosailor]

let's see if I can screw up my math, daddle.

"(4) Trojan T-105, 464 A-h @ 12V, US$683
(8) Winston LYP160AHA, New, Jumpers, 320 A-h @ 12V, US$2863 "

The trojan bank is 464AH @ 12V for $683.
The Winston bank is 320AH @ 12V for $2863.

The Trojans can be cycled to about 1/3, for 154AH of useful capacity, and at that discharge depth they're rated for what, a thousand cycles?

The Winstons can be cycled to 80% for 256AH of useful capacity at the same thousand cycles, more or less?

So you've got about 60% more useful capacity from the Winston pack, but it has cost you 4x more to get that. About $4 per AH per cycle for the lead, against $10 per AH per cycle for the lithium.

Making the lithium 2-1/2 times more expensive.

OK, what numbers did I get wrong? Not just claims but demonstrated. And what other bang are you getting for the buck, like more free space, less dead weight, faster charge times...what sold you on it?

[s/v Jedi]

Originally Posted by hellosailor

let's see if I can screw up my math, daddle.

"(4) Trojan T-105, 464 A-h @ 12V, US$683
(8) Winston LYP160AHA, New, Jumpers, 320 A-h @ 12V, US$2863 "

The trojan bank is 464AH @ 12V for $683.
The Winston bank is 320AH @ 12V for $2863.

The Trojans can be cycled to about 1/3, for 154AH of useful capacity, and at that discharge depth they're rated for what, a thousand cycles?

The Winstons can be cycled to 80% for 256AH of useful capacity at the same thousand cycles, more or less?

So you've got about 60% more useful capacity from the Winston pack, but it has cost you 4x more to get that. About $4 per AH per cycle for the lead, against $10 per AH per cycle for the lithium.

Making the lithium 2-1/2 times more expensive.

OK, what numbers did I get wrong? Not just claims but demonstrated. And what other bang are you getting for the buck, like more free space, less dead weight, faster charge times...what sold you on it?

What you got wrong? Well, when you cycle that Winston bank at 154Ah like you do the Trojan bank, you get what, 6,000 cycles? that [puts the LFP at $10/6=$1.70 vs $4 for the Trojan.

[hellosailor]

An interesting way to look at it, but why would you want to cycle the Winstons as lightly as the Trojans? Getting many more cycles out of the batteries is a good point, but is anyone installing them with that type of use in mind? For more cycles, rather than less frequent charging, less weight, all the other ways to play them? WOuld you use them that way?

[s/v Jedi]

Originally Posted by hellosailor

An interesting way to look at it, but why would you want to cycle the Winstons as lightly as the Trojans? Getting many more cycles out of the batteries is a good point, but is anyone installing them with that type of use in mind? For more cycles, rather than less frequent charging, less weight, all the other ways to play them? WOuld you use them that way?

Because 154Ah is what you use with the Trojans... changing batteries does not change that. Pretty obvious to me.

We have overcapacity Ah so that our batteries live longer, yes. When you follow the link posted earlier you will find this exact scenario and also in a price comparison.

If you don't want that, you must buy a smaller LFP bank. That comparison is also in there.

[downunder]

Originally Posted by aclmck

Somehow i got lost in this thread, the costs 4x $ ??? in Aus the cost of a 800amp hour 6 volt li is $2590 + shipping they weigh 59KG Therefore 2X $2590 = $5180 + shipping and 118 kg for 800amphours at 12 volt, now compare that to Agm i need around 7x 150 amp hour to have the same useable ah they cost around $500 each and weigh 70 kg each. = $3500 and 490 kg

What am i missing here?

You will only need 400Ap Li @ 12 V to give you similar capacity. $5180/2 = $2590.

You are ahead with Li Vs AGM in Aus using your figures.

[downunder]

Originally Posted by JayH

I’m about to undertake an inverter replacement project and looked at both Victron and Mastervolt for support of my future LI battery bank. Victron gets high marks with me for having fully configurable charge parameters and auxiliary contacts for a non-Victron BMS on their Multi and Quattro units.

The question came up on the other thread about how to manage an inverter/charger through LVC and HVC events. Well, Victron has explicit support for this through those auxiliary contacts. Close one pair to stop charging, close the other to stop inverting.

http://www.victronenergy.com/upload/...1%20-%20EN.pdf

+1 Victron is certainly planning and catering for Li. looks a good way to go.

I thought Flying Cloudwas adamant there were no chargers available catering for Li.

[Maine Sail]

Guys,

In the real world I just built a 400Ah LiFePO4 bank with full BMS, load and charge bus, Tyco EV 200 LVD contactor, HVC relays for solar, alt and shore charger plus alarms, switches, bus bars etc. and did all this for about $1800.00 in materials.. (this does not include my labor)

That is about what an Odyssey or Lifeline AGM bank of 400Ah would cost me....

[Maine Sail]

I think I am right around $1800.00 for 400Ah bank....





Expenses so far:

4 - 400Ah Winston Cells = $1032.00
Shipping Cells = $250.00
Tyco EV200 Contactor = $79.00
House Power BMS Board = $75.00 (Clean Power Auto LLC.)
Cell Modules = $54.00 (Clean Power Auto LLC.)
Aluminum for end plates/compression = $64.00
3/8" Polycarbonate = $27.00
Anodizing Aluminum = $60.00 (minimum charge)
Nuts, Bolts, Threaded Rod, Washers etc. = $12.80
Solar and Alt HVC relays = $8.60 (Cole Herse SPDT 70A)
Bus Bar = $4.80 (Blue Sea)
Switches, Alarm Buzzer etc. $44.00
Terminals = $9.50
Total Materials = $1720.70


Compare that to a bank like this:
This image has been resized. Click this bar to view the full image. The original image is sized %1%2.

Four - 100Ah Odyssey PCM2150's for a 400Ah AGM bank = $1688.00 ($422.00 per battery locally as of March 2013)
(note I am not even including the hold downs or shipping in that price just the batteries)


"Claimed Cycles" (disclaimer: I don't believe either of these "lab" derived claims and do believe they will both be lower in real world use.)

Odyssey Cycles at 80% DOD = 400 Cycles
Winston LiFePO4 at 80% DOD = 2000 Cycles

$$ Per Cycle Odyssey = $3.77 per cycle

$$ Per Cycle LiFePO4 = $0.86 per cycle

[Maine Sail]

Originally Posted by Caracal

I have seen 270a and 300A alternators. Is there a particular reason you're saying 200a (something you know will fit on your engine, perhaps)?, or something completely different?

I already had it.... I suspect I will eventually go with one of the Denso hairpin wound alternators but for now my charging will be soooo much faster that it is a non-issue compared to our old FLA bank...

[daddle]

The 50% DOD and cycle life problem for LA vs LFP is something dreamed up by the promotors of LFP. Always arranged to bash LA. My current LA bank is half 8 years old and half 5 years. They are at the end if life. However they have quietly done well more than 365x5 = 2000 cycles during those years of continuous cruising. No alarms, no balancing, no fiddling, no bad cells. Just water.

The LFP fan boys would do well to stop promoting the technology by bashing LA and come up with some honest engineered systems with honest specifications.

The same BS goes on in the EV business. Market by bashing the IC engine everybody basically likes to drive instead of creating an EV that people want to buy and drive.

That and the fratricide.

[Caracal]

Originally Posted by Maine Sail

I already had it.... I suspect I will eventually go with one of the Denso hairpin wound alternators but for now my charging will be soooo much faster that it is a non-issue compared to our old FLA bank...

Super!, Thanks, Maine

[Caracal]

Originally Posted by daddle

The 50% DOD and cycle life problem for LA vs LFP is something dreamed up by the promotors of LFP. Always arranged to bash LA. My current LA bank is half 8 years old and half 5 years. They are at the end if life. However they have quietly done well more than 365x5 = 2000 cycles during those years of continuous cruising. No alarms, no balancing, no fiddling, no bad cells. Just water.

The fifty percent was a rule of thumb "dreamed up" long before LFP batteries was even an idea, let alone a viable product. Read any book which concerns itself with lead acid batteries from, say, the 1980s or 1990s. Read some of Nigel Calders articles, read something from the Dashews, or something from the Pardeys, if you want to keep it within the boating sphere. It's really good marketing by the LFP boys if they are able to go back in time and start this "myth".

Could it be, that it's not a myth? That Lead Acid tech is well understood, and that your batteries perhaps aren't as fine as you think, or perhaps that you don't quite "get" charging cycles?

[daddle]

Originally Posted by Caracal

Could it be, that it's not a myth? That Lead Acid tech is well understood, and that your batteries perhaps aren't as fine as you think, or perhaps that you don't quite "get" charging cycles?

Oh I understand just fine ... you can wipe off your screen now ... I have a complete understanding of both the LFP and LA performance predictions from the research papers cited in other threads. I am just saying that your typical fanboy hype of LFP does not use honest comparisons ... certainly not comparisons detailed enough to be reproduced by an independent researcher... they never cite research papers or proper data sheets (there are none for prismatic LFP). You pick the most glamorous cycle life without respect to the conditions that make it unlikely (impossible) Etc. Etc. But for comparison with LA you take the actual real-world numbers from cruisers ... that trick makes a dramatic difference.

I never said my LA batteries are "fine". The are end-of-life. A long, reliable, simple, inexpensive life.

My opinion: It is not yet obvious how LFP will be able to displace LA in cruising boats. Hope it does, but I'm waiting.

[Caracal]

Originally Posted by daddle

Oh I understand just fine ... you can wipe off your screen now ... I have a complete understanding of both the LFP and LA performance predictions from the research papers cited in other threads. I am just saying that your typical fanboy hype of LFP does not use honest comparisons ... certainly not comparisons detailed enough to be reproduced by an independent researcher... they never cite research papers or proper data sheets (there are none for prismatic LFP). You pick the most glamorous cycle life without respect to the conditions that make it unlikely (impossible) Etc. Etc. But for comparison with LA you take the actual real-world numbers from cruisers ... that trick makes a dramatic difference.

If you understood charge cycles, you would know not to make the conclusion that because they have been charged every day, doesn't necessarily compare to a fifty percent DOD every day, and that the 50 percent DOD is a projected cycle life, based on that. If you discharge them more or less than that, things will change. Instead you make up some conspiracy despite the fact that 50 percent DOD standard was around long before LFP was even thought of.

[s/v Jedi]

This thread also heads towards China bashing. The mods should be on top of this as the forum should not be a place that denies non-US products a fair discussion.