Current Strategies in Solar Power ?

[MoonlightSailor]

Kyocera has many panels for sale on their site.

Does anyone know what "on grid" vs "off grid" classification means?

Are all Kyocera panels warrentied for on the water application?

http://www.kyocerasolar.com/pdf/spec.../135SX_UPU.pdf

[MoonlightSailor]

OK...So I googled it and found the answer.

So my next questions is, since marine applications are definately an "off grid" application, what is the functional difference between the two?

Can "on grid" PV panels be used for marine applications like the majority of us use them for?

[Ram]

whats the cost of these kind of batterys and how many cycles do the get?

Originally Posted by LiFeTech Energy

People are missing an important point here since this thread is all about "total efficiency" in solar charging.

You can do all the tweaking, adjusting and fine tuning, of solar regulators and adjusting the orientation of solar panels for optimum charging efficiency etc. but in the overall scheme of things it makes little difference if you have a super efficient charging set up while your AGM batteries are extremely inefficient in storing the generated power.

If you are really serious about having a truly efficient complete solar/electrical system on your boat really you need to be using a LiFePO4 battery bank and dumping your inefficient, antiquated lead batteries.

When you consider most lead acid batteries have a typical charging efficiency of 70% - 80% and LiFePO4 batteries are 95% - 99% charge efficient do the calculations yourself as to how much power your solar panels are producing which is just being wasted and not being transformed into useful, stored energy in your battery bank. In many boats it is more than likely one entire solar panel is doing little more than generating power which is completely wasted in the charging process in your lead batteries and none of this power is stored at all.

I would guess that many boat owners don't even consider this factor since they are preoccupied with trying to improve the efficiency of their charging system.

I can provide an actual efficiency comparison between using lead acid (SLA) batteries with Lithium Iron Phosphate (LFP) batteries in a standby power application running an inverter. The same efficiency considerations apply to running a load (in this case an inverter) with both battery types as they do in charging efficiency.
Sure the application might be a bit more complex and larger scale than in a boat (not too many boats I know have inverters rated at 200kVA and discharge their batteries in 10 minutes!) since the comparison is testing the performance of both battery types in a UPS but the concept is exactly the same as if it was on a boat. Think of the boating example as being a smaller version of what would be the result of these tests.

[hellosailor]

"while your AGM batteries are extremely inefficient "
I wouldn't say that, since they are 25% more efficient than the conventional wet lead batteries. They're inefficient compared to lithium batteries, but they also don't carry the baggage of new technology and ultra expensive charge controllers. The jury is going to be out for a while on that.

David-
Bear in mind that NEC "landlubber" wiring is generally planned to be enclosed in walls or in conduit, and boat wiring is not. The simple act of placing wire in a protective harness or wrap (or running it into the engine bay!) may significantly reduce the rated load capacity of the wire, as it traps heat and can lead to overheat problems.
I'd also consider 95VDC wiring on a boat to be something that needs special care, but not necessarily the same care as the low-amperage (15/20 amp branch circuits) used in a home. On the boat, tinned "Type 3" stranded wire. In the home? plain solid copper. In either case, yeah, there's enough power to make caution a good idea.

By the way, Kyocera does have their warranties buried on their web site, but the ones I saw specifically say the warranty doesn't apply toi damages caused by installation or use on a "mobile vehicle". In other words, zero warranty when you put a conventional panel on a boat. At least for the lines I saw there.

[sww914]

Originally Posted by Ram

whats the cost of these kind of batterys and how many cycles do the get?

I agree. How much money will it cost me to own them is an important question. They may be better but if they cost too much it doesn't matter. I can't find any place on the web to buy their batteries except for the laptop batteries.
A Ferrari is faster but it costs a lot and you can't haul manure in it.

[barnakiel]

Originally Posted by LiFeTech Energy

People are missing an important point ...

... If you are really serious about having a truly efficient complete solar/electrical system on your boat really you need to be using a LiFePO4 battery bank and dumping your inefficient, antiquated lead batteries.

... how much power your solar panels are producing which is just being wasted ...

I cannot quite see how with an average boat installation of two to four panels (10-20 A of charge) vs. at least 400 Ah (often more) of battery bank and an MPPT controller any considerable amount of energy is wasted. In fact, none is wasted if you have a controller that allows for direct loads once the batteries are full.

Finally, battery usable (in a life-cycle) Ah per buck, PLS ...

barnie

[barnakiel]

BTW as far as panels go I can see that now there is at least one brand that claims to be at least 20% more efficient per ft2. Good thing to go for the more efficient thing too as often the unshaded area for installation is the limit.

b.

[LiFeTech Energy]

Originally Posted by sww914

I agree. How much money will it cost me to own them is an important question. They may be better but if they cost too much it doesn't matter. I can't find any place on the web to buy their batteries except for the laptop batteries.
A Ferrari is faster but it costs a lot and you can't haul manure in it.

Good question. The answer is the total cost of ownership of a lithium battery is approx 70% of the cost of lead acid when all factors are taken into consideration. Of course the initial cost is more expensive but the longevity and performance compared to a lead acid battery are far superior.
Inverters and other electronic equipment work must better and will have a longer life when run off LiFePO4 batteries because of the nice stable voltage which doesn't drop as the battery discharges (until the final 10% of capacity before a recharge is due).
For a comparison between both types of batteries you can go to the following article on the EBAA website-
http://www.cn20090810.p-client.net/w...Technology.pdf

[LiFeTech Energy]

Originally Posted by sww914

A Ferrari is faster but it costs a lot and you can't haul manure in it.

You can if you put a tow bar on the back. I would like to see that!

[LiFeTech Energy]

Originally Posted by hellosailor

"while your AGM batteries are extremely inefficient "
I wouldn't say that, since they are 25% more efficient than the conventional wet lead batteries. They're inefficient compared to lithium batteries, but they also don't carry the baggage of new technology and ultra expensive charge controllers. The jury is going to be out for a while on that.

"Ultra expensive charge controllers"...Quite the contrary actually and simpler than for lead acid charging. With lead acid batteries you have several stages such as "equalisation" charge" adsorption charge" etc. which are used with lead acid batteries due to their built in inefficiencies.
There are only two charging stages with LiFePO4 batteries ie, constant current (CC) approx 90% and constant voltage (CV) approx. 10%.

The guys who have changed over from lead to lithium are amazed how simple the changes in programming their existing solar regulators are since all they do is disable "equalisation" and change the end of charge voltage from 14.4V to 14.6 V and that is it. Some companies such as Morningstar are now writing dedicated LiFePO4 charging programs for their regulators so you don't have to make the changes manually in the program settings.

[LiFeTech Energy]

Originally Posted by Ram

whats the cost of these kind of batterys and how many cycles do the get?

The cost and number of cycles will vary greatly between manufacturers.

For house power application the warranty alone for LiFeTech XPS series batteries is 5 years / 3000 cycles to 100% DOD (whichever comes first)
When you consider if you deep discharge a lead acid battery 100% repeatedly you may get 300 cycles life and the warranty period alone of the replacement lithium battery is 10 times this (3000 cycles).
Of course this is warranty only and some of the early cells in the factory are still working after more than 7000 cycles.

The initial purchase cost of any lithium battery is more expensive than lead acid but they are cheaper over time.
Many of the lithium batteries aimed at the DIY market are available from several websites.
LiFeTech batteries are a professional product which are directly supplied mainly to manufacturers/OEM's, auto makers, solar equipment manufacturers, etc. This is due to the fact that all batteries are only assembled to order and each battery is supplied with its own QC factory test report.
There are several options available which will affect the price depending on the level of computer monitoring which is provided with the batteries. They can also be supplied as either complete factory battery packs or "designers packs" (for building a battery into unusual shapes to make the most of unused spaces). There are also various protection options such as automatic low voltage disconnect etc.

[hellosailor]

"at least 20% more efficient per ft2. "
That's not too meaningful out of context. Some panels are rated for 11% efficiency, others for 17%. That's over 50% "more efficient" from one to the other. And still very INefficient compared to 100%.

"There are only two charging stages with LiFePO4 batteries ie, constant current (CC) approx 90% and constant voltage (CV) approx. 10%."
Nah, we've done that dance. You say no controller or cheap controller, and your competitors over at Genasun most strongly suggest using a controller that costs as much as the batteries do. What was it, $2k for the batteries and another $2k for the matching controller? Which would be reuseable for the next set of batteries, one hopes, but still doubles the already steep installation cost.

"For house power application the warranty alone for LiFeTech XPS series batteries is 5 years / 3000 cycles to 100% DOD (whichever comes first)"
I don't recall you ever mentioning the five years before. that sounds suspiciously like the ~four years that laptop batteries last before they go belly-up, used or unused. And it is only half of the ten years that premium wet-acid batteries (like Rolls and Surette) commonly get in properly managed systems. Why five years? That would require 600 total discharge cycles per year to reach 3000 cycles, and in common marine use, that's crossing the line into fantasy and fiction isn't it?
What sailor runs a 100% deep cycle on his batteries TWICE each and every day?? What kind of user application is that?

[LiFeTech Energy]

Originally Posted by hellosailor

What sailor runs a 100% deep cycle on his batteries TWICE each and every day?? What kind of user application is that?

You are missing the point. The 3000 cycles warranty is obviously the worst case scenario and in practice boat owners would not be discharging to 100% DOD so the batteries will have a working life of much longer than the warranty period alone.

[LiFeTech Energy]

Originally Posted by hellosailor

.
You say no controller or cheap controller, and your competitors over at Genasun most strongly suggest using a controller that costs as much as the batteries do. What was it, $2k for the batteries and another $2k for the matching controller? Which would be reuseable for the next set of batteries, one hopes, but still doubles the already steep installation cost.

Yes that is correct. Genasun must use a more complex and expensive BMS/controller since they use inexpensive (in terms of lithium), low quality Chinese LiFePO4 cells. From their website they look like Sky Energy cells (the blue prismatic cells).
These cells have poor quality control during manufacture and some cells will fail in a short time if no BMS is used. This is due to considerable variation in internal cell impedances from one cell to the next which leads to some cells becoming overcharged while others will be undercharged (IF THEY ARE NOT CLOSELY MANAGED).

A good rule of thumb is-
poor quality cells = more diligent balancing/monitoring required
good quality (matched cells) = cell imbalance is less of a problem since cells which are matched in terms of internal impedance/actual capacity will have less of a tendency to naturally become unbalanced during charge/discharge cycles compared to cells which have little or no quality control during manufacture.

For example the cells in my car starting battery fitted to my Toyota Camry are matched racing cells. There is no BMS in this battery yet I have been driving my car and starting it several times a day for more than 2 years now (since the battery was originally fitted) and it has performed perfectly.
The same could not be said if the cells used were straight off the production line and no BMS was fitted.

[hellosailor]

"You are missing the point. The 3000 cycles warranty is obviously the worst case "
Au contraire. The point is that you are claiming 3000 cycles--but in point of fact, the five year limitation will end the warranty first.
That's exactly like GM now advertising cars with the "longest" 100,000 mile warranty, which is made knowing that the average buyer puts on 12,000 miles a year, so the warranty will end in five years at 60,000 miles. That 40% shortfall allows GM to spend a lot less money than they would have to spend on a simple 100,000 mile warranty.
I don't say that's your intent--but I do know major corporations structure their warranty, their warranty finances (set-asides) and marketing based on that specific and intentional sleight of hand.
If they are expected to be cycled once every other day, that's 912 charge cycles, not 3000, that they can be expected to last. If you have the faith that they can do 3000 cycles--then come up with an unprecedented 10-year warranty, and watch what that does to increase sales!

Poor quality cells, matched racing cells, production line....Tell me, does the average customer ever know if they really are getting "red snapper" in a fish restaurant? (Most often, they are not.) Some things, we just have to decide on faith. Spending 10x more on batteries, on faith, requires a real leap.