AGM still makes more sense than Lithium

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  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: AGM still makes more sense than Lithium
    Your experience is definitely atypical and I would suspect your system wasn't set up right.

    No doubt living full time in a motorhome is atypical. Sun would shine on my battery compartment door and heat two of my batteries up more than the others. That issue alone created is own set of problems that was never ending and basically incurable.

    Like I said, I could write a book about all the issues. My situation was not good.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: AGM still makes more sense than Lithium
    feedhorn wrote: »
    Lead Acid works great for engine starting. A few seconds of load then immediately recharged.
    You are over generalizing. The FLA (Flooded Lead Acid) batteries that most people are familiar with are SLI or "cranking" batteries which have the characteristics you mention. But that is more related to their construction method and active material chemistry rather than to being in the lead acid group.
    You can make lead acid batteries optimized for deep cycle by increasing the thickness of the plates (at the expense of surface area) and by using different additives (or no additives) in the alloy from which the plates are constructed. You can also fiddle with the electrolyte composition, especially when using an AGM type.
    SMA SB 3000, old BP panels.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: AGM still makes more sense than Lithium
    As yet there are still points of cost and availability to consider. But if there were no pioneers like PNjunction there would be no hope of progress. :D

    I'm just standing on the shoulders of giants who have been there now for 4 years or so.

    My main objective is to stay honestly objective, and of course put it to the test hands-on. There is a lot of money to be made by those who DO know upon those who don't, and I'm trying to filter through all that blather.

    Simply put, if I can't treat my lifepo4 bank like I do my agm bank for the most part, (some particulars are different of course) I'm not interested. I'm not going to hang a rat's-nest of external wiring increasing my odds for additional points-of-failure.

    If I were an agm manufacturer, I'd start to compete with that industry by providing individual cell taps on my 6 cell agm's, and selling a boatload of cell-level balancing equipment. If those cell taps were actually brought out in real life, most people would be absolutely shocked at how imbalanced their agm's are, and go rushing straight into the hands of that industry. Blinky lights all over the place must mean I'm protected. :)
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: AGM still makes more sense than Lithium
    PNjunction wrote: »
    I'm just standing on the shoulders of giants who have been there now for 4 years or so.

    My main objective is to stay honestly objective, and of course put it to the test hands-on. There is a lot of money to be made by those who DO know upon those who don't, and I'm trying to filter through all that blather.

    Simply put, if I can't treat my lifepo4 bank like I do my agm bank for the most part, (some particulars are different of course) I'm not interested. I'm not going to hang a rat's-nest of external wiring increasing my odds for additional points-of-failure.

    If I were an agm manufacturer, I'd start to compete with that industry by providing individual cell taps on my 6 cell agm's, and selling a boatload of cell-level balancing equipment. If those cell taps were actually brought out in real life, most people would be absolutely shocked at how imbalanced their agm's are, and go rushing straight into the hands of that industry. Blinky lights all over the place must mean I'm protected. :)
    Lead acid chemistry, whether flooded or sealed, has the property of tolerating a low current overcharge, allowing equalization of a series string of cells, whether in one battery or many batteries.
    Lithium chemistry, on the other hand, does not tolerate overcharge well, which leads to the need for external balancing networks.
    I hope that BMS for lead acid would never catch on. :)
    SMA SB 3000, old BP panels.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: AGM still makes more sense than Lithium

    Technically a per cell management system for lead-acid would make them work better.
    But as Inetdog says it is not needed; the chemistry is very tolerant of errors in Voltage and current compared to other types of battery.
    PNjunction is correct in his pursuit too: LiFePo will not gain general acceptance if it can not be used as simply as lead-acid can.

    I've seen a lot of "amazing new" batteries in my day. Funny how most people are still using century old lead-acid. If it costs too much or is too complex people are not going to go for it, even if it is better technology; "good enough" will do for most folks.
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: AGM still makes more sense than Lithium

    Yep,

    And some people still get around with a Horse and Buggy. Its good enough for their life...

    Thank God for the Chinese making a country that will go beyond what seems just good enough.

    As nano technology moves into commercial batteries we should have batteries 10 times more powerful that today's lithium.

    I hope my next set of batteries to run my motorhome are just 4 D-cells.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: AGM still makes more sense than Lithium
    feedhorn wrote: »
    I hope my next set of batteries to run my motorhome are just 4 D-cells.
    And that they are in a very secure and well protected box!!!
    SMA SB 3000, old BP panels.
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: AGM still makes more sense than Lithium
    inetdog wrote: »
    And that they are in a very secure and well protected box!!!

    Maybe a small water-gel packet inside each cell so if they get in trouble they could just blow off some steam.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: AGM still makes more sense than Lithium
    inetdog wrote: »
    Lithium chemistry, on the other hand, does not tolerate overcharge well, which leads to the need for external balancing networks.

    You see this a lot from bms manufacturers trying to sell to their main market demographic, which are not in the same category as those of use using lifepo4 for low voltage, low-current storage. External balancing circuits are popular with high-voltage, high-current users like EV and Ebike, which frequently abuse them by running them well above and below the normal specifications. Little wonder they need life-support to cover up the abuse.

    We on the other hand, can take simpler measures, and have the luxury of taking better care of them than they do, without anything more than a sanity check on a voltmeter. Of course the bms proponents don't want to hear this, and say that dumb DIY'ers like us can't handle even a simple voltmeter.

    Because we are dealing with a chemistry that does not need to be fully recharged, perhaps a simpler solution would be to read that statement backwards, and realize that maybe instead of overcharging, just ease up a little bit! :) In our application of low voltage, low current, once the battery is in balance, it stays there until you force an incident upon it.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: AGM still makes more sense than Lithium
    PNjunction is correct in his pursuit too: LiFePo will not gain general acceptance if it can not be used as simply as lead-acid can.

    It doesn't need to gain general acceptance, but the problem we face as inquisitive storage users, and not motive-power users, is that all the information and disinformation comes mainly from those outside our service application. There are those that are using them as storage banks, but it is sometimes hard to get above the din of general theorizing. Even though what the storage guys were saying seemed true, I spent my own money and time to find out on my own, and either duplicate their testing efforts, or improve upon them. So far so good - I haven't come across any "gotcha's" yet.
    I've seen a lot of "amazing new" batteries in my day. Funny how most people are still using century old lead-acid. If it costs too much or is too complex people are not going to go for it, even if it is better technology; "good enough" will do for most folks.

    Exactly. I'd rather have a competent guy who knows his stuff and populate my garage with a quality set of Rolls Surrette's, rather than having some guy from the tech-squad toss a bunch of plastic lifepo4's batteries with a rat's nest of wiring all over them and walk away.

    All I'm saying is that yes, these are amazing batteries, they are available, but most importantly, anyone can verify what I and others are saying about them being used in storage banks simply and inexpensively for themselves. No NDA's, no special equipment, and so forth. I'll get off my soapbox now and leave that for the GBS cell review. :)
  • feedhornfeedhorn Solar Expert Posts: 103 ✭✭
    Re: AGM still makes more sense than Lithium

    I've been watching the adoption of LiFePO4 batteries in power tools. The first adopters went out of business because they tried to get by without BMS. Now that single chip BMS solutions are available the adoption is going strong mainly because of the increased safety factor of LiFePO4. You have to look hard now to find any manufactures that are not using LiFePO4. BMS is the wave of the future in all modern battery systems and once you get used to using them its no worse than carrying a Hydrometer around to manage your batteries. Gee, BMS might even be a better way to manage batteries.

    BMS is good, get used to it.
  • jonrjonr Solar Expert Posts: 1,360 ✭✭✭✭
    Re: AGM still makes more sense than Lithium

    I agree. Some people think that a few small wires to provide balancing is some big deal to be avoided. I'd much rather have that than deal with a hydrometer, inefficient charge acceptance profiles and adding water.

    I am available for custom hardware/firmware development

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