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[eBay Plus] 12V Lithium LiFePO4 Battery 100Ah $339.96 or 125Ah $382.46 Delivered @ VicOffroad eBay / SunyeeInternational eBay

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[eBay Plus] 12V Lithium LiFePO4 Battery 100Ah $339.96 or 125Ah $382.46 Delivered @ VicOffroad eBay / SunyeeInternational eBay
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happyadventurer on 13/02/2021 - 14:25 ebay.com.au (338 clicks)
Last edited 13/02/2021 - 23:52 by 1 other user
PLUS15FB

Original Coupon Deal

This is not a battery to start your car. It is a deep cycle battery for running auxiliary appliances such as 12v fridges

VicOffroad
100 Ah for $339.96 - Link

125Ah for $382.46 - Link

Sunyee International
100 Ah for $339.96 - Link

125Ah for $382.46 - Link or eBay Plus not required discount applied at checkout.

No need to get into a debate about price/quality. Yes these are significantly cheaper than branded LiFePO4 batteries but in most cases you could get two of these batteries for the price of one branded battery. Watch Youtube capacity test for these batteries. The test method wasn't perfect but better than nothing.

I think for the price of these batteries they are worth it if you don't need to critically rely on the battery for your adventures. However they only come with a 1 Yr warranty.

Those looking for a cheap battery but longer warranty should check out the VoltaX batteries which come with 3 years warranty although it can only discharge max 50A continuous. Link

Automotive Battery Deep Cycle Battery LiFePO4 Lithium Battery Rechargeable Battery

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VicOffRoad
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Sunyee International

closed Comments

  • lplau on 13/02/2021 - 15:09

    I wouldnt use these as car batteries too.
    Excessive heat from being under the sun would kill it off pretty quickly.

    • kob2040 on 13/02/2021 - 15:24

      I would, so much lighter than an acid battery you would get more miles per gallon….

      Its more the cold they don't like…….

      • [Deactivated] on 13/02/2021 - 16:38
        +2

        These are NOT cranking batteries and high temps will reduce battery life. Specialist cranking, under-bonnet LiFePO4s do exist - for a price.

      • raven492 on 13/02/2021 - 21:57

        The 100ah has a max output (5 second burst) of 200 amps, which is less than 1/3 of my car battery's CCA rating. you'd cook these pretty quick trying to use as a starter.

    • tetsuma on 13/02/2021 - 15:26
      +2

      Or maybe just close the bonnet.

    • bobbyz0r on 13/02/2021 - 15:42

      LiFePO4 is one of the most resilient battery chemistries. It also has very high current discharge capabilities (probably better than most AGM batteries) for good quality cells like A123 ones. It's main downside is energy density for size and cost.

  • stumo on 13/02/2021 - 15:12

    Seems like a good deal. Worth a shot. Bought the 125Ah and will check its actual capacity.

    • virtual81 on 13/02/2021 - 16:45
      +4

      Would be really really keen to know actual capacity.
      Price seems suspiciously cheap.
      Would you consider PMing me with the results, or post back here?

      • stumo on 16/02/2021 - 13:41
        +1

        Its arrived today. Currently charging at 25A.

        Casing quality seems on par with other budget units.

        Will report on capacity tomorrow after her first workout.

      • stumo on 16/02/2021 - 22:50
        +1

        Lol the 125Ah is only 80Ah.

        This was charged at 14.3V constant current at 25A until it tapered off to zero amps. Then topped off again 14.4V just to make sure. (Note that normally you should only charge with 14.2V but I wanted to do a best case full charge giving the BMS opportunity to top balance).

        Then I drew a 250W ~22A load. The pack auto cut-off at 80Ah and 11.6V. Which is good because the BMS is well protecting from undervoltage. I reset the BMS and tried drawing only 50W but it was adamant it was cutting off at 80Ah.

        So end of the day, 80Ah is too far away from 125Ah for me. So back it goes.

        I will do another test tomorrow just to re confirm, then send it back.

        • flipfire on 17/02/2021 - 00:25

          No surprise its under the stated capacity. I bought a tow rack from Sunyee recently. Their listing specifically said 5mm thick steel, got 2.5mm.

          Good luck with the refund. They ignored me until it got escalated with Paypal. Return shipping will come out of your pocket but Paypal can reimburse.

          I'm sticking with AGM batterys until Lithiums come down to decent price.

          • stumo on 18/02/2021 - 12:21

            @flipfire: Returns process seems pretty easy so far. Just click on return through eBay and it gives you a free shipping label for AUpost. I posted it thismorning and the tracking automatically enters into the eBay system. PayPal says refund should be in my account withing 3 business days of return

        • [Deactivated] on 17/02/2021 - 11:01

          Interesting, thanks stumo. 11.6V appears a little high, although a good safeguard for battery longevity. Depending on the battery that means roughly 8% capacity or ~10Ah is unavailable. Still well under the claimed capacity. Looking forward to T2.

          • herbo on 17/02/2021 - 11:15

            @[Deactivated]: You guys seem well-researched on this topic. Are there any lithiums that you have heard about / tried and would recommend? I'm looking to re-power a 24 volt electric boat motor. There's a guy with a pretty comprehensive facebook page called Powerpaul Australia, he's done some tests on these Prishda batteries https://prishda.com/product-category/batteries/ they seem to do well, but I note that warranty info is conspicuously absent.

            • stumo on 17/02/2021 - 11:49
              +3

              @herbo: I can only comment on one other pre-packaged off the shelf 12V LFP battery. It was from EV Power over in WA. It was sold as 45Ah. But it actually provided 55Ah between its built in BMS cutoffs. Its been running fine for 4 years in my motorhome.

              Back to this one. 11.6V is quite a high cutoff on an average per cell basis. But maybe one of the cells was lower than the others? Either way the rated Ah should be between the built in cutoffs.

              Test 2 I have charged it at ~8A. It took 10 hours, so that supports the 80Ah capacity. Certainly nowhere near 125Ah. I also then tried to trickle in as much as possible even down to 0.2A for an hour before the built in BMS cut off.

              I am now draining it at 100W. Will report back tonight. Though I doubt its going to magically gain the missing 45Ah lol.

            • [Deactivated] on 17/02/2021 - 13:16
              +1

              @herbo: Boaties were early adopters herbo. Probably worth looking at boating forums for experiences.

              Price is no guarantee of quality but backup, knowledge, service usually adds quite a bit to price. At least you know they'll be around if you have warranty or other problems.

              I haven't looked at waterproof ratings or specific single 24V batteries etc but in general all these have very good/solid reputations at this point from my research:

              • DCS (good phone app), Victron, Relion & Enerdrive ($$$);
              • Amptron $$;
              • Ev Power (low warranty iirc) & SolarKing ($).
              • Renogy products generally get good reviews but they appear to have sfa Australian presence.

              I guess if you're going to buy cheapie(s) then best to do it from a b&m marine/other outlet - they have a reputation to protect.

              • herbo on 17/02/2021 - 13:42

                @[Deactivated]: Thanks for the replies. This may be a dumb question, but I've read that the maximum current draw for my 24v electric motor is 56A and a Solarking 24v battery (as an example) has a max continuous current of 40A. Therefore I assume that the Solarking is not suitable?? Would that assumption be correct?

                • flipfire on 17/02/2021 - 14:02
                  +1

                  @herbo: Not suitable, Electric motors have a high inrush current when starting up.

                  Is it for a trolling motor?

                  • herbo on 17/02/2021 - 14:12

                    @flipfire: yeah Motorguide bow mount, 80lb thrust, 24v. Have 2 x AGMs at the moment. Would more than halve the weight if I went with a lithium.

                • [Deactivated] on 17/02/2021 - 15:55
                  +1

                  @herbo: Seems strangely low. Wonder what cell types they used for that battery or if the specs weren't added to the website properly - as I found on another of their products. My guess is they copied and pasted specs without quality control. Might be worth asking .

                  Amptron and others are 100A / 200A (1C / 2C - 10 secs) or thereabouts.

                  • herbo on 17/02/2021 - 17:31

                    @[Deactivated]: Yep, might ask the question. That's the spec on their own web-site and it's the same on the low energy developments ebay listing.

                    • [Deactivated] on 17/02/2021 - 17:40

                      @herbo: LED is a reseller (with a b&m shop) of SK batteries. They offer an extra year's warranty on some batteries for only a few $ more. Likely they simply copied what's on the SK website.

                    • flipfire on 17/02/2021 - 17:40

                      @herbo: Could be a limitation on the BMS. At any rate, you dont want it to trip

      • stumo on 17/02/2021 - 19:36
        +2

        80Ah confirmed. Discharged at 100W this time. Thats a very long way off 125Ah.

        I wonder what the 100Ah pack is actually.

  • sjp770 on 13/02/2021 - 15:13

    Anyone used this brand / no name brand?

  • ausbob71 on 13/02/2021 - 15:38

    Would these be suitable to replace flooded lead acid batteries in a golf cart?

    • [Deactivated] on 13/02/2021 - 16:57

      Yes. Do you have a charger with a lithium or AGM profile?

  • macmanluke on 13/02/2021 - 15:55
    +4

    I would be very surprised if they are even half the rated capacity

    Way too cheap for lithium and too light (8kgs - reputable brands are mostly in 12-13kg range for 100ah)

    • happyadventurer on 13/02/2021 - 16:10

      I don't think you can completely rule out the quality of this battery purely on weight. Obviously we can probably be certain that it's not going to be as good as reputable branded batteries but that doesn't mean that it's not fit for purpose. There are too many variables that impact on the weight e.g. cylindrical cells or prismatic cells, the gauge of wires and type of battery management system.

      The Youtube link I provided, he was able to charge his 100Ah battery up to 72Ah. However his charger wasn't delivering the recommended charge voltage of 14.4V. Rather it was charging at about 13.5V. He's also commented that he's been able to run his 12V fridge with no issues on trips since he bought it 6 months ago and is still running well.

      I think based on the above and inherent reliability of LiFePO4 cells and that this battery uses cylindrical cells (a damaged cell won't render the entire battery useless), it's worth the gamble.

      • stumo on 13/02/2021 - 16:13
        +2

        Yeah that guys testing method was absolute crap. Drawing 50A continuous and claiming that it ls 65Ah, when in reality his meter wraps at 65Ah. Then the charging debacle.

        I've been looking at some of his other vids and he really shouldnt be making vids about stuff he knows very little about.

        • happyadventurer on 13/02/2021 - 16:16

          I know :) but that was all I could find on this battery. Like I said, it's better than nothing haha. Considering that he got up to 72Ah at 13.5V that's promising enough for me to give this battery a go.

        • Krazyy on 13/02/2021 - 16:17

          What is the correct way to test capacity?

          • happyadventurer on 13/02/2021 - 16:24

            @Krazyy: I'm not a auto electrician however from my understanding. It's better to fully charge the battery and see if it can delivery the energy (watts) that it supposed to be able to. So 12.8V x 100Ah = 1200 watt hours (Wh). Use a watt meter to record the watt hour consumed by an appliance (e.g. 12v fridge) and see if it can run the fridge for 1200Wh. But you'd need to factor in that the battery management system shouldn't let you use the entire battery so it should cut out at 80% depth of discharge (won't go past 20% state of charge or else risk damaging the battery). So 1200Wh x 0.8 = 960Wh.

            • [Deactivated] on 13/02/2021 - 16:30
              +1

              @happyadventurer: Lithiums with decent BMS' can be run "flat" - ie 100% DoD. Discharging until the BMS low voltage protection kicks in should result in AT LEAST the advertised capacity.

          • [Deactivated] on 13/02/2021 - 16:27
            +3

            @Krazyy: Will Prowse has a bunch of excellent videos on LiFEPO4s. You'll have to search to find one his videos where he fully discharges a 12v lithium.

    • [Deactivated] on 13/02/2021 - 16:18
      +1

      Agree. It's VERY suggestive of poor quality and overstatement of capacity. 12 months warranty says all you need to know - industry standard is ~3 years. No mention of active cell balancing which is important for battery life. Likely the BMS is cheap and nasty.

      • happyadventurer on 13/02/2021 - 16:28

        Not completely true about active cell balancing. Battleborn which is highly reputable made in USA lithium battery company uses passive cell balancing.

        • [Deactivated] on 13/02/2021 - 16:33

          There are videos discussing which is better, but the point is decent BMS' will have either active or passive balancing.

          • happyadventurer on 13/02/2021 - 16:37

            @[Deactivated]: My understanding is that you can't have a battery like this without some sort of balancing. We can assume that if active cell balancing is not mentioned then it must be passive cell balancing.

            We don't have a Will Promise tear down of this battery so who knows how good this battery is. We don't have a tear down of the other numerous more expensive LiFePO4 battery in the Australian market so who knows how much better are they really than this battery. They may simply be overpriced for what you get.

            I think the simplicity of LiFePO4 batteries (fit for purpose cells + passive balancing + BMS) it's honestly not all that hard to get right. And if you're doing anything that could put you in a life threatening situation if your battery stopped working, this battery is worth a shot for it's price.

            • [Deactivated] on 13/02/2021 - 16:45

              @happyadventurer: Prowse and others have often mentioned that the weakest link in cheap 12V lithium batteries is their flimsy BMS.

              Don't know why anyone would buy a lithium at this price with 1 year warranty but that's personal choice.

              • happyadventurer on 13/02/2021 - 16:49

                @[Deactivated]: I agree with you about the BMS. I bought this battery to give it a go and like I said, you could two of these batteries for the price of one branded battery. The VoltaX now comes with 3 year warranty at $469 for 100Ah. I'll put that in the post as an alternative. Though you might be turned off since it only weighs 9.5kg despite the 3 year warranty :)

                • Krazyy on 13/02/2021 - 16:55

                  @happyadventurer: The voltax batteries only have discharge rate of 50a…

                  • happyadventurer on 13/02/2021 - 16:58

                    @Krazyy: That's why I didn't choose the VoltaX battery despite the 3 year warranty. It's probably why they can offer the warranty.

                    I'm not going to be discharging the max discharge current of 150A of the battery in this posted deal (only running 7A fridge) so considering that it is $60-$100 cheaper than the VoltaX and I have the ability to discharge continuous more than 50A, I chose to buy this one despite the 1 year warranty.

                  • [Deactivated] on 13/02/2021 - 17:05

                    @Krazyy: A few things which help differentiate quality. Specs (inc discharge rates), weight, warranty, reputation. You can also ask about the cells used but it's a leap of faith to take the word of many retailers.

                    • Krazyy on 13/02/2021 - 17:13

                      @[Deactivated]: Every company / manufacturer needs to start somewhere and thus build their reputation somewhere.

                      In regards to the cells. What questions should I throw at them?

                      • happyadventurer on 13/02/2021 - 17:16

                        @Krazyy: Cylindrical, prismatic or pouch cells, what grade is the cell and who is the manufacturer.

                        • Krazyy on 13/02/2021 - 20:17

                          @happyadventurer: Done. They said they would check with the supplier and get back to me.

                      • [Deactivated] on 13/02/2021 - 17:21

                        @Krazyy: Ask them for details of the cells they use (and where they're made) and the specs for individual cells. While you're there ask them about what BMS they use and its weight.

                        • Krazyy on 13/02/2021 - 20:17

                          @[Deactivated]: Done. They said they would check with the supplier and get back to me.

                • zeomega on 13/02/2021 - 22:40

                  @happyadventurer: If the battery dies at the 13th month mark, has only been delivering 80% of the capacity of the branded battery. Does it deliver the economies of scale warranted for the investment?

                  IMHO No.

                  • happyadventurer on 13/02/2021 - 23:44

                    @zeomega: That could be said for anything i.e. If you spent $1000 on a branded 100Ah battery with 3 year warranty and it died on 3 year 1 month..

                    I don't know why people are judging this battery purely on it's discounted price and warranty when they have not tested it for it's quality. There is no substantial amount of reviews on the internet to say that this is a bad battery.

                    Any company would happily provide a longer warranty but to do so they may increase the purchase price. If this battery offered a 3 year warranty but priced it three times the price to offset the risk of a warranty claim per year. You are buying the same quality battery but now for three times the price however the consumer thinks that they are buying a better quality battery when they are not.

                    This battery has cylindrical cells which can partly explain why it's much cheaper than the branded $1000 100Ah batteries which use prismatic cells (e.g. Amptron, iTechworld 120X) that are much more expensive to manufacturer.

                    If you look at the sold history the 100Ah used to sell for $500 and the 125Ah $600.

                    LiFePO4 cylindrical cells is not a new technology, it's been around since the 1990s, but it is relatively new to the deep cycle battery market compared to AGM and with it's substantial longer life compared to AGM. You can be certain that battery companies know that they can sell you a $1000 battery if it promises to last substantially longer than AGM.

                    The argument that just because something cost more and provides a longer warranty doesn't always mean that is substantially better quality. Or that the cheaper alternative is not fit for purpose.

                    Not everyone has $600-$1000 to buy 'the best of the best' 100Ah LiFePO4. Everyone may as well buy the best of the best cranking battery but they don't. Most people just buy a cheap to mid range cranking battery and guess what.. they can start the engine just fine.

                    If you could buy a battery for less $ to deliver max 50A continuous discharge current because you're never going to exceed 50A compared to a battery that is much more expensive because it needs higher quality cells, thicker wires, BMS etc. to be able to provide 150A continuous discharge current. Wouldn't you be ok with buying the cheaper one?

                    • jonathanxing17 on 26/03/2021 - 14:31

                      @happyadventurer: Even though we are the competitors. But I have to back you up here. People only judge on the price say that cheap batteries can't deliver the power that labeled on its case or saying 100ah battery should be 13+ kgs. They haven't opened the battery and do testing on the capacity. There is no review on the internet either. How could they be so confident saying the low-mid range $400-500 batteries are bad?

  • herbo on 13/02/2021 - 17:03

    Anyone tried Solarking lithiums? They seem to have a decent rep on the caravaners forum.

    Wish this deal would come back https://www.ozbargain.com.au/node/522576

    • beatsntoons on 13/02/2021 - 19:36

      Yep, I have a small one that I initially used for powering a telescope. The mount doesn't draw a lot of power (only 4A max when slewing), but it's a cool little thing. So small and loads of power.
      Ended up getting a Jackery in the end as I needed the Sine-wave + regulated DC, but I still use the Solarking to power the Jackery in the field.

  • AMLagonda on 13/02/2021 - 18:37

    This is so tempting but so suspicious

  • feisty on 13/02/2021 - 20:59
    +1

    It could not possibly be any worse than the last AUSTRALIAN MADE Century piece of crap AGM I bought last year for $100 less.
    I hate it when I buy Australian and the product sucks.

    • [Deactivated] on 13/02/2021 - 21:20

      What was wrong with it?

      • feisty on 13/02/2021 - 22:03
        +1

        It wouldn't hold its charge. Century didn't want to know about it. The killer is I'm fanatical about looking after batteries and have lots of experience having three under the bonnet of the landcruiser, 12 motorbikes and two agms in a camper. . I can't afford not to buy quality and especially can't afford to abuse them.
        Batteryworld chap said century have just stopped making them and are clearing out all their stock through supercheap sales etc. It's the non maintenance free model fyi

  • flipfire on 13/02/2021 - 21:38
    +4

    Sunyee absolutely do NOT have good online service. They will ignore the hell out of you until Paypal escalation steps in.

    You've been warned!

    Vicoffroad is the same company as Sunyee btw.

    • happyadventurer on 13/02/2021 - 22:11
      +1

      I suspected that they may be the same company as they sell the same products. I wonder why they need to have two businesses going and why the Sunyee website doesn't provide the address but Vicoffroad does.

    • AMLagonda on 13/02/2021 - 23:44
      +1

      Cheers, just as I thought…

    • Cannabot on 15/02/2021 - 21:50

      Sunyee = VicOffroad = Atem Power

      Don't bother buying from them if you will rely on whatever you are buying.

  • tatnal on 14/02/2021 - 08:36

    Can anyone suggest a good battery box with a meter (do they even come with a meter)? Noticed that vicoffroad have the 100Ah and 125Ah with battery boxes but just looks like a box. https://www.ebay.com.au/itm/125Ah-12V-Lithium-Battery-LiFePO…

    • herbo on 14/02/2021 - 09:47
      +1

      I went through researching and buying one recently. I found that the Kmart box was the cheapest. I needed a bit tougher and some more Anderson plugs because I wanted to mount a DC to DC charger on top of it and have solar input. I ended up with a Hard Korr box that I got from Snowys, it’s obviously a fair bit more $. I changed some of the internal wiring a bit to suit the charger and I’m happy with it so far. There are other businesses selling a box the same as the Hard Korr one, for example this is the same.

    • happyadventurer on 14/02/2021 - 11:17
      +1

      I got the 'Mobi battery box' off of ebay for $63. It has a meter. Cheapest I could find with a hard plastic lid. I think the other cheaper ones have a flimsy soft plastic lid which you can tell as the lid is the shiny plastic type.

    • tatnal on 14/02/2021 - 12:54

      Thanks. Doing a bit of research this morning suggests that most come with the standard voltage meter. I was actually looking for one that showed Ah as well but looks like it will be a separate device.

    • [Deactivated] on 14/02/2021 - 13:33
      +2

      Many boxes have a voltmeter display, which is only a rough guide to DoD for lithiums because they maintain voltage until late in the discharge cycle. There's a table here (below the discharge graph) which can be used as an approximate guide to remaining battery capacity.

      Probably you also want one of these "wattmeters", or two if you want to monitor both input (eg solar) and output (fridge etc) while you're camping. Note the 150A limit. Anderson plugs also have limits but for typical use this isn't a problem. Meter goes between battery and input/source (solar controller) and/or battery and output/load (fridge, lights etc)

      Plenty of videos showing wattmeter setups on the net, eg Kickass

  • happyadventurer on 19/02/2021 - 10:37

    For anyone curious, I got the 125Ah battery and completely discharged the battery until about 10v when the BMS shut down the battery. Then charged it all the way back up. Ended up charging 103Ah or 1380Wh. As with LiFePO4 batteries I believe you can only use up to 80% of the Ah (50% for AGM), the results make sense. 125Ah battery x 80% = 100Ah or 1600Wh x 80% = 1280Wh.

    I'm pretty happy with my purchase! Here's to hoping it lasts for a few years at least. Though I'm pretty confident that it will considering the longevity characteristics of LiFePO4.

    Proof

    • stumo on 19/02/2021 - 13:14

      Interesting. Mine cut out at 11.6V both times. 10V is more what Id expect to see for a emergency level cutoff. (I wouldnt be relying on that, you shouldnt really go below about 11.2V. Or above 14.2 for that matter.) Thats where the 80% comes in, not AFTER the absolute max rating. The useable range you are getting is only going to be about 80Ah.

      Maybe mine had a dodgey cell. And only 80Ah from a 125Ah pack lol. But I note once it got down to 12V it dropped really quickly after that, which is not nornal. This was all using the absolute max range fron the BMS - high cutoff to low cutoff. So my actual usable range would be less than even the paltry 80Ah absolute.

      You are still getting conned at 80% though. These arent bare cells, it is a 12V pack. They are supposed to supply at least the rated power between BMS cutoffs.

      I would be demanding a refund of the difference in cost between a 125Ah and the 100Ah that you got.

      • happyadventurer on 19/02/2021 - 13:36

        The spec sheet says 'Discharge Cut-off Voltage 10V''. Therefore it's strange that yours is cutting out at 11.6V. Is it the appliance cutting out due to an in built battery protection setting or is it actually the battery? Like with fridges you can set when the fridge turns off when the battery reaches a certain voltage.

        It would sort of make sense that you are only getting 80Ah from a 125Ah pack if it's cutting out at 11.6V as you haven't reached down to 10V.

        I don't think I am getting conned at 80%. From my understanding the battery management system will cut out at 10V to protect the cells. There's 20% Ah left to be used but the battery management system won't let me use it to protect the cells.

        This is where the difference in lead acid (AGM) and LiFePO4 differ in my opinion. A 100Ah lead acid battery doesn't have a battery management system so theoretically you could use all 100Ah but then you would be damaging the battery as every says that you should only use 50% of it's Ah capacity. So a 100Ah lead acid can give you 100Ah but you should only use half of that 50Ah. A LiFePO4 has a battery management system allowing only 80% of the Ah capacity so you can't use 100% even if you wanted to.

        • stumo on 19/02/2021 - 14:25
          +1

          It was the BMS inside the pack that was cutting out at 11.6V. Full open circuit on the battery. Had to apply 12V to the battery to get the BMS to activate and supply any voltage again.

          There isnt 20% of the pack still left below 10V. That is the limit at which cells become irreparably damaged. Look at the voltage curve of any LFP cell, it has a knee point around 2.7V at which point the voltage drops exponentially. 2.5V (10V at pack) is well past that knee.

          The missing 20% is you being conned. The rating is supposed to be between these cutoffs. As it is on other packs.

          This is like you buying a 100Ah AGM, that is really only 80Ah, and you will be pulling 50Ah from per cycle. Probabky worse because taking it to 10V will kill it quicker than even an AGM at 100Ah.

          • happyadventurer on 19/02/2021 - 15:24

            @stumo: Thanks for making me understand. Very interesting that yours is cutting out at 11.6V and mine at 10V.

    • [Deactivated] on 19/02/2021 - 14:38
      +1

      Second time you've claimed Lithiums can only be used to 80% DoD happy. Not sure where you got that but I'd be interested in reading it. EVERYTHING I've read and seen says this is totally incorrect! The 80% is a recommended figure to help longevity. Properly-managed lithiums can be "100%" depleted without damage although over time tests show that this shortens their usable life (so minor damage is being done to the chemistry).

      Your 80% calc has no bearing whatsoever UNLESS for some obscure reason a BMS has been set to cut out at a much higher voltage than 10V (closer to 12.7V), which is not what you've claimed. When a LiFePO4 12V battery is at 10V it's essentially fully depleted. There is no extra 20% waiting to be discharged. Below that and you risk damaging the cells. A battery at 80% DoD should read ~12.7V.

      Looks like you've been sold a 103Ah battery disguised at 125Ah - which for the price some people might be happy with. Personal choice. It means you actually have ~80Ah for regular use, assuming you're aiming for longevity. With quality cells there's nothing wrong with occasional depletion apart from the reduced longevity I've mentioned. It's early days, and dependent on cell, build and BMS quality, operating conditions etc but the sweet spot for performance/longevity seems to be ~60% DoD.

      The important thing for you is that you're happy with your purchase. Nevertheless the seller is misleading consumers and should NOT be advertising the product as 125Ah.

      • happyadventurer on 19/02/2021 - 15:22

        Thanks mate and stumo for making me realise. I don't think I got that idea specifically reading it from somewhere. I think it was more so a natural assumption I made. I trust that you are more informed than me about cell technology so will trust that you are correct.

        80Ah with potential to occasionally go beyond that, is not bad as it would allow me to run my fridge for about 3-4 days. Based on the price and A I am getting, I'm still happy with the purchase. Although I do agree with you about the false advertising.

        Yep it is early days so we will have to see how long this battery lasts. Considering that it cost me only $330 I'm not going to be devested if it died shortly after a year. It would be lesson learnt and I'd look into a replacement :)

        I'm currently doing a discharge test so I'll report back if the result was any different to the charge test.

        • stumo on 19/02/2021 - 16:14

          In addition to what possubly said, you need to be careful at the top end of the pack as well. They are not "drop in" replacements for gel or AGM like sellers like to claim.

          Now that theyve been around for a decade or so, the early adopters have founf that charging at 14.4V permanently decreces capacity by at least 10%. 14.0 to 14.2V is considered the optimum charge voltage.

          More importantly you should not float charge these at all. This is impractical for most applications, so best compromise is to float at 13.1V. - 13.4V depending on the "resting" voltage of your pack. Any higher than the resting voltage and it starts slowly "plating" the electrodes, also resulting in permanent capacity reduction.

          So these 2 points clearly are not compatible with "drop in" AGM or even gel chargers. You really need a fully configurable charger with the above patameters if you want the pack to last longer than a well maintained flooded pack.

          And with the above parameters you will be giving away maybe 20% capacity, but it will last for a decade or more.

          So its not a bad price for an 80Ah pack. But in my case its not worth it. I was looking to replace my DIY 160Ah pack with 2 of these. But with 2 same as like I got I would be getting a 120Ah pack for $700 which isnt good value at all.

          • [Deactivated] on 19/02/2021 - 17:04

            @stumo: Prowse says for testing the absolute MAX charge is 3.65V/cell, or 14.6V. This is probably okay for TESTING high quality batteries but the vast majority of opinions I've read (including his) say that forcing the last bit of charge into a lithium can damage cells quite quickly, as you say. Some Enerdrive lithiums say 14.4-6. Many suggest that ~13.2 - 13.4V is 100% at standby but I recall Prowse had a Battleborn which was north of 13.6V when at standing 100% capacity. Even if you squeeze 14+V in, voltage quickly settles back to high 13s (eg ~13.7V) when you stop charging. This is for new batteries of course, older more-used batteries will likely have lower top thresholds.

            This is what Enerdrive says about using non-lithium profile chargers:
            If you want to use a lead acid charger on a lithium battery you can, HOWEVER, you must NOT use a lead-acid charger if it has an automatic “equalisation mode”, which cannot be permanently turned off. A lead-acid charger that can be set to charge no higher than 14.6v can be used for regular charging and then MUST be disconnected after the battery is fully charged. DO NOT leave the lead-acid charger connected to maintain or store the battery, because most will NOT maintain the proper voltage charge algorithm for lithium batteries and damage will occur to the battery.

            From what I've seen there's quite a bit of inaccurate and out-of-date advice on 12V lithiums on 4WD and even some lithium battery seller websites, which is a trap for those new to the technology. Always best to read widely and consult the marketplace leaders' websites. There's a huge amount of discussion, video and testing out there for anyone interested.

            • happyadventurer on 19/02/2021 - 17:48

              @[Deactivated]: I am tossing up whether or not to return this battery considering that I only got 100Ah and getting one with a longer warranty for a bit more in price. What do you guys reckon about this battery or this one

              • [Deactivated] on 20/02/2021 - 14:26

                @happyadventurer: Haven't heard of either, sorry. Most of these ebay cheapies are almost certainly rebranded generic Chinese out of different small factories so the important thing is REAL specs, and support. Neither has a comprehensive list of specs that you see from reputable brands. Unless seller 2 can provide details of the testing then I'd take the claims re the capacity test with a grain of salt.

                B1 - low weight, no specs to speak of, query wrt seller knowledge and support. Can't see any warranty info.

                B2 - second seller has a b&m store which helps, 12.8kg so closer to the mark, only 60A continuous. Haven't got a clue what he means by "Stand Voltage End Discharge 8.8V" (nor does he I'll bet) but if it means 8.8V @ 100% depletion then I'd run a mile. As we've both said, anything under 10V is a cell killer. Any half-decent BMS should cut supply at or before 10V. Might be worth asking him.

                Bottom line is that any of these cheapies MAY give good service for the price, but they are made to a price and you take a leap of faith wrt warranty and specs.

              • stumo on 23/02/2021 - 14:56

                @happyadventurer: Agree with above.

                If I were you, I would request a refund for the difference between the 100Ah (that you got) and the 125Ah that you ordered.

                I was open to that percentage based partial refund but the eBay sysyem just went straight to a full refund and free return, which was a really easy process.

                I think its better the devil you know with these eBay specials. If you are happy with 100Ah for your application, then request a partial. Use eBay messaging contact seller in the first instance to avoid the auto full refund process.

                • happyadventurer on 23/02/2021 - 17:25
                  +2

                  @stumo: I ended up going for a refund like you Stumo and ordered TPower battery instead for a few reasons:
                  1. They have a brick and motor store in Melbourne
                  2. They have been on eBay since 1999 so a business around a long time and hopefully will be in future for warranty purposes
                  3. Battery is substantially is more heavy and physically larger
                  4. They have a large range of varying batteries which adds to idea that they are reputable
                  5. They indicate the battery cells and BMS in the pack

                  I actually just received it today so will see how it goes. It 'feels' much better quality than the one posted in this deal. Being 3 kgs heavier, better quality terminal posts and physically larger. Will carry out the capacity tests and let you know if substantially different to advertised 100Ah.

                  • [Deactivated] on 24/02/2021 - 20:21

                    @happyadventurer: Specs still say "End voltage 8.8V". You might want to ask him what that means. Bol with your purchase.

                    • happyadventurer on 24/02/2021 - 23:29

                      @[Deactivated]: Yeah I will try to find out what it means.

                      So far discharge and charge test have been good with both tests achieving the battery's 1200Wh. Just finished charging the battery was able to charge 14.6v, 1250Wh and 95Ah.

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