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Because it only turns into a veiled salesmanship job - unintentional or not. Without knowing the exact power needs, and geographical location to determine what the solar insolation is, NO CHEMISTRY is plausible unless you want to wing it.
Lifepo4 is such an upsetting technology, because the "lead acid mindset" can't get over the too-good-to-be-true aspects of it. It also turns wizards into nobodies, because aside from just sizing your bank right and operating it within some common-sense guidelines, you can get on with your life and don't really need to spend a lot of time in forums trying to make the most of it.
It breaks the status-quo, and that deep down is what really upsets people who may have dedicated a lifetime of knowledge to the proper care and feeding of lead acid. All that goes out the window, and are now desperately searching for anything to nitpick on for justification. I know it disturbed me - but that is only after I had actual physical experience.
Offended by the relative ease of operations, the only thing left to do is be a naysayer.
So unless the op wants a sales pitch, which is better served at a professional distributor, I'll ask the question to you:
What system of lifepo4 do YOU have? If none, then why don't you get on the field with us. Cost is minimal for a benchtop. Until then, most of it is just disgruntled naysaying. It's boring after this many years quite frankly.
Mine is a small 12v system, both 20ah and 40ah consisting of GBS cells. (easily scaled into the kw or more range if I really wanted to go there), with NO automatic balancing. Common sense things like you'd use with any chemistry are there, such as an LVD and monitoring. Since I'm running in a "Sub-C" environment like most anyone that uses them for solar storage does, I don't encounter the issues always brought up by other applications, like EV. Although I don't need it, an iCharger 306B was used for initial sanity balance, and to also measure the IR. A West Mountain Radio CBA-IV was used for capacity testing of each cell.
Because I like hydrometers, flukes, and battery maintenance in general (lead-acid included, I LOVE pure-lead agm too!) this may be overkill for some.
The op needs ENGINEERING before salesmanship. That will come when the power needs and solar insolation, or at least a general geographical location can be provided.
Until then, what are YOU using to properly evaluate lifepo4 under real world conditions? Or is it all just talk? Don't be a spectator. Get on the field with us, even with a small benchtop - otherwise what you say is only noise from the stands.Comment
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Wrong again. Battery type has nothing to do charger power. The amount of power is determined by YOU, and only you can answer that question. You have to determine how much power measured in Watt Hours you will use in a day. You have to be able to generate that much in a day to replace it. You do not need to know or care what battery type that is. If you use 1 Kwh of power a day and 3 Sun Hours in winter you had better have have a 500 watt panel, with a 40 amp MPPT controller and a 12 volt 400 AH battery. Makes no fricking difference if it is FLA, AGM, LFP or any alphabet soup battery you want. The only thing that matters is HOW MUCH MONEY will you pay up. The most expensive option you can choose with the shortest life time is AGM and LFP. Some 400% more at end of product life.
It is bad enough to decide to go off-grid and pay 5 times more than the POCO wil charge you using FLA, but do you realy want to pay 20 times more using AGM or LFP? That is the real question you should be asking yourself. Because as of now all your assumptions are false. Any decision based on false assumptions does not end well or work out.
The very first step of any design is to determine the objective. For off-grid solar the objective is HOW MANY WATT HOURS IN A DAY. Until you know that, you have no biz doing anything. The equipment used is just a minor detail and child play.
AGM batteries do have a place in a Solar applications, a very rare specific NICHE application. Such as:
- Unusual installation orientation like on their side.
- Where spills cannot be tolerated like on aircraft.
- Extremely High Charge and/or Discharge currents are required. You thought they could not be high rates when in fact that is what they are made for.
- Extreme Cold below-30 F
MSEE, PEComment
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No pitch, actually I want to be told that I should just get the cheapest ones I can find as warranties are'ent worth anything and the extra efficiency can me made up for with just a couple of extra panels
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I found this sentence a bit confusing, your saying AGM is the most expensive and shortest life, LFP is the most expensive but 4x the life of AGM?
Ok relax Sunking, the only biz I am doing is trying to learn from people who know more than me so I can make the best decision when Im ready to buy, thats why Im here.Comment
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I'm not sure you'll ever have the lifetime required to weed through all the bunk to get to the facts in time. This is a global phenomenon more or less on all boards when dealing with lifepo4, not just here. Personal politics, outside interference from those outside our low-voltage/low current use in the EV/Ebike/RC modeling field, hackers using inappropriate cells of different li-ion chemistries held together with duct-tape, junk-dealers trying to pawn off vehicle crash batteries to newbies all add to the confusion.
It's a conspiracy I tell 'ya!
Interestingly enough, do you ever see lifepo4 cheerleaders interjecting into lead-acid threads at every turn? Thank goodness that is not the case, but the reverse is always true.
While I do not like FLA at all, and could counter much of the broad brushstrokes applied to their favor, you won't find me trying to dissuade anyone from using it if they want to. Instead, I'll provide some of the minimum generalities such as a current spread from C/12 to C/8 for newcomers and leaving the rest to those who actually own them.
.... wait, here comes a pat on the back ... (ugh)..
Sad really. I don't know if there is a good cure that is not so draconian that it defeats the purpose of a public forum. Wait- what? Private forums perhaps or a public one with totalitarian rules stated up front for participation? hmmmm...Comment
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Are there some Aussies who know of people they have dealt with that will do the right thing when I go to purchase?
Ive found a few places ev-power and Lithium Batteries Australia, seems to be a big difference in price although the LBA guy says the batteries are made here and they come in a very sturdy looking metal case, the EV guys go for a more of the 'Duct Tape' approach which I dont mind in itself as my batteries will be indoors so no need to pay for all that metal.Comment
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Not sure how you came to that conclusion, but most the EV crowd is very savy and leaps and bounds ahead of Solar. The EV guys are the Pioneers, the solar crowd are a bunch of tight asses who really do not know much, and just following the crowd like sheep to be slaughtered.
EV crowd can justify LFP batteries because weight and energy density are the two most important characteristics of an EV. Means nothing to a solar system.
You can buy and operate a FLA battery for 5 and a few up to 10 years. There are a couple out there. A really good FLA cost around $200 to $250 per Kwh. If it last say 5 years means just in battery cost alone you paid $1250 / 1825 days = 69-cents per Kwh just for the batteries. You want AGM or LFP? They cost twice as much and last half as long. That means $2500 / 913 days = $2.74 cents per Kwh or 4 times more than FLA.
This should make you stop and ask yourself:
Hey Stupid; why do I want to pay $0.70 to $2.70 per Kwh taking something off-grid when I can buy unlimited amounts of power from the greedy ole Power Company for 11-cents per Kwh. I hope you can answer yourself without embarrassing yourself.MSEE, PEComment
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Generally true, however everyone's situation is a bit different. I have to tell you my eyes lit up when I saw the weight of LFP compared with the 330lb FLA batteries I was considering.
I have removable steep basement stairs, which while have an external Bilco door, are not close to code. There is also a 2' rise to the stairs because the house is built above grade 3-4'. I would have had to have rigged a boom to lower the 330-pounders straight down where the removable stairs are. 8 trips carrying an LFP under each arm down the stairs without removing them was a very positive attribute.
That said, I am very close to getting electricity for about $10,000, compared with what was well over $100K when I was solo. I found 2 other neighbors to get electric, and we have all approvals except my HOA to go over a remote creek that nobody can see. And if one more of multiple lots goes on the same line within 10 years, I get $5000 back.
I should mention it was Dereck's advice that I bang my head against a rock and wake up that caused me to redouble my effort to get electricity. It has been a Herculean effort, but one that may pay off.Comment
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