Lithium or Solar?

[Wraith_Mac]

The prices he quotes for AGMs etc are in Australia, not America.
They are very expensive to import here due to their weight.
That is why my emphasis was on what he actually paid for his Winstons, as they have to be imported to both countries, the costs are more comparable.
He didn't self import which is cheaper still as his supplier no doubt had a profit margin in there.
If initial cost is your only criteria for choosing batteries and recharge rates, life cycle and weight don't matter then you've made a good choice, no one is trying to get you to change that choice.
You didn't even read his article, yet you critique it, did you even note it was a catamaran?
Mac

[Maine Sail]

Originally Posted by scoobert

ok so now we are up to $530 each. for 210 AH.
Lifeline GPL-4DL $ 527.00

still not close to the quote on that persons website.
and i did a quick google on trying to find universal battery early failures, with no luck.

And a 160Ah bank of Winston cells will run you $704.00 at current pricing.. Considering you should only cycle the AGM's to 50% DOD and you'll still have a tough time getting back above 90% while off cruising the 160Ah bank is a good match up to 210Ah of AGM..

But if you want a closer Ah to Ah you are at $880.00 for a 200Ah bank of Winston cells. When going LiFePO4 there is no need to go Ah to Ah between LA and LiFePO4 because you get 70-80% usable capacity on LiFePO4......

That said Li is not for everyone at this point and I'm afraid many who've jumped in early will destroy cells due to improper charging or use.

Of course standard old FLA's are still the best value. I can install a 230Ah bank of 6V GC2's for $160.00. Does not get much cheaper than that.... I don't find AGM's to be a "value" for a cruising boat unless you really can utilize some of the good features of them.. Sadly most who install AGM's are not utilizing the benefits they offer such as high bulk charge acceptance...

[deckofficer]

scoobert,

Putting aside all the other benefits of LiFePO4 cells such as light weight, charge acceptance, very low sag under heavy draw, nil Peukert, the usable capacity and cycle life alone make them the cheapest in the long run.

Before marine applications, I've been using batteries for EVs and off grid homes for over 30 years. Used them all, from 6 volt golf cart batteries, L16s, 2 Volt large single cells, and AGM. If your use is for a house bank on a boat that you cruise full time, you are dollars ahead going with LiFePO4 cells, not to mention your back will thank you for not having to lug dead lead on and off your boat every couple of years.

[T1 Terry]

It's a pity that any thread where lithium is mentioned gets hijacked by either those wanting to turn into a science masters paper deliberately using terms no one else would understand or pushing their own agenda for the purpose of sales or to justify their own choices.
Why can't these people just leave these threads to stay on topic and remain in every day language. They could start their own thread on the topic they want to discuss, why hijack someone else’s thread, do they feel this is the only way they can get an audience?

T1 Terry

[goboatingnow]

Originally Posted by T1 Terry

It's a pity that any thread where lithium is mentioned gets hijacked by either those wanting to turn into a science masters paper deliberately using terms no one else would understand or pushing their own agenda for the purpose of sales or to justify their own choices.
Why can't these people just leave these threads to stay on topic and remain in every day language. They could start their own thread on the topic they want to discuss, why hijack someone else’s thread, do they feel this is the only way they can get an audience?

T1 Terry

could you be more specific here, all I see here is a critique of pricing models, could you specifically "quote" the sections you refer too , so as to avoid the " whoes he talking about"

dave

[T1 Terry]

Originally Posted by noelex 77

Terry I disagree with this.
Typical charging voltages with lithium are lower than with lead acid and therefore the gain will be greater for MPPT.

I guess we will always disagree on this one. My experience with different controllers has shown to me the quality MPPT units get their gains when a load pulls a battery voltage low, the lower the voltage compared to the *Vmp, the more the gain. The difference between 11v and 15v is large enough to be worth using impendence matching to gain more amps, but the difference between 13.4v and 15v is not enough, once voltage losses are introduced, the gain is very little if any, lithium batteries do not drop their voltage under load.

T1 Terry

*(Voltage maximum power, the point where the solar panel make the most amps at the highest voltage, this voltage point drops as the panel heats up, the 18v often quoted is at 25 degC, most working panels heat to 70DegC or more an the Vmp drops to 15v or lower)

[goboatingnow]

Originally Posted by T1 Terry

I guess we will always disagree on this one. My experience with different controllers has shown to me the quality MPPT units get their gains when a load pulls a battery voltage low, the lower the voltage compared to the *Vmp, the more the gain. The difference between 11v and 15v is large enough to be worth using impendence matching to gain more amps, but the difference between 13.4v and 15v is not enough, once voltage losses are introduced, the gain is very little if any, lithium batteries do not drop their voltage under load.

T1 Terry

*(Voltage maximum power, the point where the solar panel make the most amps at the highest voltage, this voltage point drops as the panel heats up, the 18v often quoted is at 25 degC, most working panels heat to 70DegC or more an the Vmp drops to 15v or lower)

mppt always gives you gain over PWM, its just in some cases , rather like this , there isn't much of a price performance gain. ( leaving aside the issue of quiescent current) anyway lets not rehash another thread.

dave

[scoobert]

Originally Posted by deckofficer

scoobert,

Putting aside all the other benefits of LiFePO4 cells such as light weight, charge acceptance, very low sag under heavy draw, nil Peukert, the usable capacity and cycle life alone make them the cheapest in the long run.

If your use is for a house bank on a boat that you cruise full time, you are dollars ahead going with LiFePO4 cells, not to mention your back will thank you for not having to lug dead lead on and off your boat every couple of years.

well to begin with i would need a new charger.
a new regulator for the alt may be needed.
the initial cost is very high.
if i do not keep the boat for the entire battery's life, then i will not recover that cost.

on a 600 amp bank, i can spend $850 and get flooded.
they weigh about 70# each, and can all lifted in by the yard boy for $10.
sure they weigh more, but weight of the battery bank is the least concern.
these are rated for 1000 cycles at 50% DOD.
so whats the start-up cost of the lithium bank?
the other good option is a traction battery.

if i was very concerned about weight i could leave the 250 gallon water tank with 50 gallons in it, and get a water maker.

[goboatingnow]

Ive said this before, Justifying Lithiums on either cycle life or retained capacity is a dangerous idea given the state of knowledge we have.

Justify them on their other attributes, absolutely but today Scoobert is right, it doesnt really stack up financially ( but thats not to say they arnt way better batteries which they are)

dave

[scoobert]

Originally Posted by goboatingnow

Ive said this before, Justifying Lithiums on either cycle life or retained capacity is a dangerous age given the state of knowledge we have.

Justify them on their other attributes, absolutely but today Scoobert is right, it doesnt really stack up financially ( but thats not to say they rant way better batteries which they are)

dave

the day the price is at parody, they will be on my yacht. no doubt.

[noelex 77]

Originally Posted by T1 Terry

[COLOR=black][FONT=Verdana]the lower the voltage compared to the *Vmp, the more the gain

Agreed
My lead acid batteries are typical of a boat system and spend much of the day, and nearly all of the peak production hours (which supply most of the output and therefore where the gain from MPPT is most significant) at a voltage higher than the maximum recommended charge voltage for lithium.

Lower charging voltages for lithium mean more gain from MPPT

Lithium voltage sag is less, so at night the lithium voltages are higher, but solar does not work well at night

I will record my lead acid batterie voltage each hour during the day tomorrow if you are willing to charge a lithium battery for a few cycles at these voltages. It will be a good test of how well lithium withstands a very high charging voltage.

[goboatingnow]

Lower charging voltages for lithium mean more gain from MPPT

What T1 Terry means , is that with lithiums , taking into account the actually operating Vmp of 18V panels at operating temperature, Vmp is close to the Li charge voltage and doesnt really vary much over the charge cycle.

This is true, but its a price performance argument, once Vpanel is different from Vmp and the current is =Imp then MPPT will deliver a technical advantage , but it may be little at a big cost.

of course the argument fails for higher voltages typical now in larger panels or series strings.

[Wraith_Mac]

Scoobert,
Just because your charger can't do an AGM or custom [adjustable] setting, what makes you think the OPs shore charger doesn't?
If you are only referring to your projected set up costs what does that have to do with the OPs question regarding lithium for fast acceptance?
So what if he needs an external regulator, say a Balmar 614, for optimum performance, they're a very useful item to have for any serious cruiser.
They are not a must have, just the best way to go for any house battery system.
Are you sure you're trying to answer the OP or just grinding an axe?
Cheers,
Mac

[goboatingnow]

yes but the point Scoobert makes is perfectly valid, you can get decent performance at a good bang for your buck out of LA and thats the truth. That doesnt invalidate those that want to "go" lithium, but one must be careful not to engage in "wishful" decision making.

dave

[noelex 77]

Originally Posted by goboatingnow

What T1 Terry means , is that with lithiums , taking into account the actually operating Vmp of 18V panels at operating temperature, Vmp is close to the Li charge voltage and doesnt really vary much over the charge cycle.

The lead acid charging voltages are higher and therefore closer to Vmp than lithium.

Maximum charge voltages on lithium are in the order of almost a whole volt lower than lead acid.

This gives much more gap between battery voltage and Vmp for lithium batteries leading to more potential gain from the voltage conversion inherent in MPPT.