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GENTRAX 12V 200Ah Lithium Battery LiFePO4 $349 Delivered @ HomeWork&Play Amazon AU

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Ripper price for a 200Ah, this will definitely out drum the bunny.

Price History at C CamelCamelCamel.

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  • Great price

  • +3

    I can't help but see the "[R]eal Capacity" as "eal Capacity" and therefore a slippery rating, like an attempt o convey confidence but failing to do so.

    • +1

      wouldn't be surprised if its got roof tiles in there like those fake volta ones on the FB groups.

      no way that's real capacity for that price.

      the entire page spec sheet is out of whack.. one section says its lead-acid/agm and in the actual description it says it only has 3 cells. LifePo4 12v batts are usually 4x prismatic cells.

      doesn't even say its max load current, which gives away that it doesn't have a good bms/balancer.. not to say it cant be redeemed by upgrading it.. but that's another $100+ expense

      • +1

        While the listing has many issues, the discharge ratings are on Amazon.

        Max.Charge Current: 100A
        Continuous Discharge Current: 100A
        Max.Discharge Current (5sec): 200A

        Gentrax sells cheap but seemingly not terrible generators, and now more recently, LiFePO4 batteries.

        The Amazon seller in this case does not seem to be Gentrax. They didn't supply an invoice yet, so not sure who they actually are.

        IIRC, they are the same seller as some other very discounted (via coupon) products here. Such as power stations, which seemed to have high DOA rates and/or arrived fully discharged.

        So this might be a seller that clears out older stock across various brands. EG for LiFePO4 batteries they might be at or past the date the sell by date, and so self discharge will mean they need to be charged soon or risk damage. Or batteries were they have found a batch is not meeting spec, or there is quality control issues with the actual cells.

        Or something else similar. It might be imported fakes.

        Whatever the case, they appear to put minimal effort into making a well written listing. But presuming the battery meets the advertised spec (who knows!) then despite the low 100A output, these were very cheap for a 12V200Ah battery rated for 3000 cycles.

        https://gentrax.com.au/products/gentrax-12v-200ah-lifepo4-ba…

  • +2

    This is sold and shipped by a third party - it's not an amazon protected product.

  • +2

    Too bad these can't be connected in series or parallel - https://gentrax.com.au/products/gentrax-12v-200ah-lifepo4-ba…

    • How can a battery not be parallel connected, seems wrong, need replacements for my 24v system, this sucks on every level!!

      • +3

        It's because of the BMS used. Parallel batteries can have high equalisation currents if / when SOC varies, which the BMS of each battery needs to be able to deal with and not trigger any protection modes.

        So cheaper batteries with cheaper BMS say no parallel usage, so they don't need to use a BMS that can handle it without problems. You can still connected them in parallel and though should be fine if you keep the loads low. But if there is an issue, they may deny warranty.

        Series connections also face similar issues, as well as additional complications. Even batteries with higher end BMS will limit the number of batteries in parallel (or series). For a larger setup, ideally you want BMS that can communicate with each other.

        With cheap enough cells (these were very cheap if they are any good) then you could open them up and put a better BMS on them and still come out ahead.

        This is a good explanation with more detail.

        https://www.master-instruments.com.au/tech-talk-article/3/Ex…

        • Or you could parallel the cells and only use one bms

          • @Bill Burn: OR get a good bms of ebay that has Bluetooth and some other toys attached

          • @Bill Burn: Yep, that is what I am referring to when I say "With cheap enough cells (these were very cheap if they are any good) then you could open them up and put a better BMS on them and still come out ahead."

            EG, you could use the cells from multiple batteries in parallel or series to build whatever overall battery you want, and then use a single BMS for the entire thing.

  • +2

    Great price indeed, though bummer it seems to use the same 100A BMS as the 100ah unit. It would have been ideal if it could proportionally deliver 200A for powering a 2400w inverter, then it would have made a neat single battery solution for alot of applications.
    Has anyone confirmed what cells are in these gentrax units yet ? Single (probably double in this case) prismatic cells or multiple pouches ?

    • +3

      In the specs it says "lead acid, agm" but that surely is incorrect info as well.

    • +1

      pouches. Not going to get prismatic at this price.

      I have the 100Ah and it's quite a fair bit lighter than my prismatic 100ah, which is ideal as a portable source.

      • +2

        Have you ever measured the actual capacity? I'm wary of these cheapo's after being tempted by one that claims in capital letters to watch out for scam capacity in their blurb. Only to find it had 65% of the stated capacity lol.

        • +2

          Yes, with a victron charger. It charged 105AH at the first charge. I've not drained it since and measured the discharge, but that is a good start to be able to charge to 105AH. Factor in some losses, it would be close to the mark

  • +2

    A real ripper price! What's the catch here? Even has 100amp continuous discharge. Does that mean with the right inverter this will power something up to roughly 1200 watts? Or am I completely wrong?

    • +5

      Yeah should do 1000-1200w pretty comfortably.

      Unreal price, I already have a VoltX 200Ah in my battery box and I'm tempted by this for no apparent reason!

      • Is it hard to find an appropriately sized battery box for this? The 100ah boxes are everywhere. But this box must be a bit bigger?

        • +1

          Mine is custom made from marine ply with a 30A DC-DC and a stack of cig lighter sockets/usb's etc.

          We take it camping when there's a big group of us and it supports 10-15 of us no worries with 500W of solar connected.

          • +1

            @XeKToReX: Man, that sounds like a cool setup. Nice work. What brand of panels do you use? I am just using cheap ebay ones, but so far so good.

            • +3

              @HappyPants: I came from 2 x 134Ah AGM's, basically did our backs every time we had to load/unload it haha!

              It's great, also have a 350W Inverter I can connect via an Anderson connector to run a TV etc if we want to watch the footy.

              Panels are just 2 x 250W foldable Adventure Kings I run in parallel, in good sunlight they have no issues maxing the 30A DC-DC

              Also have the option to connect to a car to charge if we do run into a few bad days of sunlight.

              • +2

                @XeKToReX: Sounds good. I try here to recommend people to make their own power station out of a

                cheap or better) 100Ah or 200Ah LiPo4 battery as you can customise it with extra gear like

                better/bigger capacity solar charger/dc-dc charger (which has Solar MPPT build in), as well as

                Higher spec Watt output Cig/Anderso/USB A & C etc etc. Gives you much more capacity for price

                and good project to learn and can repair/upgrade if needed in future.

                • +1
                  • @shap08: Yep, and a good price to boot for the Smart/blutooth 50A version.

                    Started using these Victron smart solar chargers this year and so far happy with them.

                    For many people the smaller 15/100 or 20/30/100 would be all they need in a mobile set up.

            • +1

              @HappyPants: You can get solar panels from your local electrical wholesaler. Around $200 each for a 400 something watt panel. They're 37 volts so use a mppt regulator to charge 12v batteries. There's a good value one on eBay search "60amp mppt solar controller" get the one that's silver alloy looking. It will work on battery banks from 12v to 48v. It's very good for the $.

    • +1

      LPT: If you have to ask what's the catch, the answer is usually you.

      • -1

        The catch is, people like me who need series capable batteries can't understand why this battery can't be used in series, seems beyond belief, no other chemistry has that restriction!

  • It seems physically small; Dimensions: L: 345 x W: 190x H:245mm for a 200 AH battery. Or am I missing something?

    • Normal for lithium, you’re probably thinking of AGM where a 120AH is like 30kgd

    • Pouch cells are much smaller I think

  • +2

    12V 200AH and only 20kg sounds very "thin"…. and the gentrax website states 19kg.

  • +1

    Good price definitely. I am still hoping to hear some real word use reports of these batteries.

  • +1

    Can this be used as a secondary battery for car audio, being recharged by the alternator & main car battery?

    • +2

      I don't see why not, you'd need a DC-DC charger to keep it topped up and as long as you're drawing less than 100A continuously then you should be fine.

      • +2

        Thank you @XeKToReX

      • HACK: use a mppt regulator as a DC DC charger. ;) https://www.ebay.com.au/itm/354874754064

        • They usually require at least 15V on the solar input. And they will pull hard AF on whatever power supply you attach, to destruction.

    • +1

      Good question!

      I wonder if it can even be used as the primary battery?

      • +6

        Not enough CCA to turn over a car. Also, these shouldn't be stored under bonnet.

        • +1

          Oh I see.

          Why not under the bonnet?
          Too much high heat. Or vibrations. Or just not good idea to keep Lithium (explosive) close to the engine.

          • +4

            @Kangal: Lithium batteries generally don't like the heat from under bonnet applications, even the much more expensive ones.

          • @Kangal: correct

          • +1

            @Kangal: There is also a problem with charging them. A regular acid battery charges from the alternator and that's a bad way to charge a Lithium battery, risk of under of overcharging can occur. I believe some additional electronics are required to manage that to turn it into a smart charge.

            That's beside the mention that these don't like too much heat.

      • .you mean a a car battery?

    • -1

      A 2nd battery for car audio? Do you need 200ah for an audio system?

    • Yeah, you'll need a suitable DC to DC charger, Lithium has a unique charge regime, all chemistrys do, but Lead acid survives a lot better if abused and costs a lot less to replace, there's even 3 main types of Lead acid that have different charge regimes if you care to make them last.

  • +1

    That almost seems to cheap, makes you wonder what costs have been cut to make it saleable for that price.

    • +1

      Battery prices have been falling over the past few years, and it's finally being passed through at the retail level.

      Having said that, the incentive to cheat on specifications is enormous. Slap 200Ah on a 150Ah battery. Most people can't tell the difference. This is a huge problem with ultra cheap lead acid AGM batteries sold through eBay and such.

    • +1

      Despite the A grade battery claim, it's possible used pouches or batteries are inside, plus a low quality BMS. If your application isn't critical then the price/warranty is the selling point.

  • +1

    Four in series - if feasible - would make a cheap 10kWh Home Battery… Pity the BMS precludes that.

    • Not ble to be wired in series or parallel! have a read of the page, something definitely wrong there!

  • I need to replace the old AGM in my camper van. If the comments are anything to go by, then this seems to be a great price. Might need to pull the trigger. Thanks for posting op.

    Is there anything that would need to change in my current electrical system for the van? Or is it a simple swap from AGM to lithium?

    • +2

      Lithium charge profiles are different to AGM so you may need to swap out chargers.

      • +1

        Thanks. I have this charger, so seems I am in luck.

        https://www.snowys.com.au/15-amp-waterproof-pwm-smart-solar-…

        • +1

          Too easy, just set it to LiFePO4 and you should be good to go!

      • Do lithium batteries last longer if always charging and topped up? I plan to install a small solar panel on the roof for constant charging when not camping. The system also charges from the alternator when driving. Otherwise I put out a mat style solar panel when camping and stationary.

        There are periods through winter where the van won't be used for a few months. So this is where I think the small solar panel on the roof will help maintain battery life. Though I'm new to the world of lithium

        Edit: the deal has expired! Damn it.

        • +2

          Yeah the coupons didn't last long :(

          For reference, Lithium batteries prefer to be left at a partial charge. If the battery is charged and left for a few months it likely won't self discharge far enough to matter. But might if there is anything draining it.

          So if you want to use a small solar panel to maintain it, you can use it with a solar charger or voltage regulator that allows you to set the max voltage. Setting it at 13.15 V means if self discharge drops the remaining charge down from full, it will be maintained close to 50% - 60% capacity. Then you just fully charge it after winter. (You need to make sure your solar charger and alternator charger is set up for Lithium though as Lead Acid voltages are too high)

          But realistically for a few months, even the normal lithium float voltages around 13.4V (~90% charge) won't give appreciable battery wear.

          • @Prong: Thanks for that info. Glad to hear that they are more resilient!

            Also, reading your comment on alternator charge, I may need to invest in a more expensive DCDC charger that has all the bells and whistles for lithium. Then I can rip out all the single components that are asking to cause trouble. It's been a build in progress over the years and the wiring is getting a bit wild. Itd be nice to have it through a single monitoring system that does it all

    • +1

      Despite what teh blurb says, its not a drop in replacement if you want it to last. You would need a DCDC charger added that will charge at about 14.4V max, and then float at 13.4V max. If you try to charge at 14.6V like a Lead battery, it will drastically reduce the cycles, and if you float at more than 13.4V it will also drastically reduce cycles.

    • +1

      If it's to start your motor, it won't have enough CCA.

      • No, it's an auxilary battery

    • +1

      Depends if your current charging setup is lithium compatible or not. If it's an older system it probably isn't compatible and will cost $$$ to upgrade everything.

      • +1

        Luckily the charger was replaced not too long ago. Specs says it can do lithium too 👍🏼

        • +1

          To check state of charge, it may be a little harder to see how full or low your LiPo battery is as voltage curve

          is very different as it depletes. If you are only draining a bit each day you will probably be fine, but draining

          more you will need to keep an eye on level. I would recommend later on installing a Battary Monitor with

          Shunt such as this https://www.amazon.com.au/Renogy-Programmable-10V-120V-Compa…

        • Should be as easy as swapping in the battery and changing the charger settings to lithium.

          Monitoring state of charge may be an issue if the charger doesn't do that itself. Which charger do you have?

      • +1

        Depends on your stuff, if your off grid it may simply have to replace the solar controller with a lithium capable one, look up your model, some lithium batteries have a BMS that can take AGM/SLA or flooded charges and correct them for the battery, this model can only be used as a single battery, cannot be paralleled or series'd

  • +1

    It's 2400Wh. Tesla model 3 nomal battery is about 57kWh. Therefore 24 such battery could power a normal Tesla model 3, right? It's just $8400 total.

    • +1

      Let us know how it goes.

    • Don't forget battery management (Tesla does it better than any other), and the cooling system for the batteries.

      • Absolutely critical for that application.

  • Are there LFP batteries for say, a UPS? Our current ones keep dying every few years.

    • You just need a charger with switchover/ups capability. Those things aren't cheap. Just remember this can't sustain 2400w for more than 5 secs. But @1200w it will last close to 2 hours…

    • There are LFP UPSes but they aren’t cheap. You can’t drop these batteries into a lead acid UPS (they charge differently).

      Just incorrect the math above - 200ah 12v batteries would last for two hours at 1200W (100A), and theoretically 1 hour at 2400W (200A) except that these batteries can’t discharge at that rate (max 100A). Other 200AH batteries can.

      • My comment specifically states 2hr @ 1200w 🤪

        • Yep that parts fine, I was more talking about the 2400W part.

  • +1

    Has anyone tried to bypass the crappy BMSs on these units to achieve higher current/parallel output?

    • Yes easily done. I have one (not on this particular model but they're all the same) where I've got a second -ve tap that's direct the the battery terminal. So if I need high current loads I can connect to my auxillary -ve and the existing positive and pull all the power I need in short bursts and not worry about the BMS. But for general discharge the main -ve and +ve terminals are used and protected by the BMS (for all it's worth)

    • Yeah it's doable to the remove the BMS and replace it with a better one, might cost another $50 or $100 though which kind of defeats the purpose. The limitation is all in the BMS, the cells would likely be fine a much higher discharge rate.

  • +2

    Showing as $599 for me.

    • Same

    • Yeah the coupon has gone

  • +1

    Oh… Missed it… Spend too much time googling..

    • +2

      if its legit, we might not see this price for awhile

    • +2

      LPT. Put it in your cart and hit checkout, but don't complete it and leave that tab open. Then do your googling. Then once its expired you can still complete checkout at the deal price, worked for me*

      • so far I have not had a cancellation yet.
      • I did this but got charged the full amount without the coupon. Damn. Have to cancel. So annoying.

        • You have to be at full checkout page, not just cart. It worked for me circa 10 minutes after it had expired.

          • +1

            @stumo: Yep i was. Took one click to purchase, order confirmed immediately…glad it worked for you though! Such a shame they pulled the coupon early.

    • Yep, I missed it too. And regret it. I fluffed around for too long. Ruined my day.

  • +12

    Cheap!

    Snagged one, and I will capacity test it and post the results here.

  • +1

    https://www.ozbargain.com.au/node/838693

    100ah pretty decent price if anyone missed on the 200ah not sure if they are any good will wait for Prong results

    • Is Prong currently doing these?

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