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Forum Index : Other Stuff : 12 volt 300AH Lithium Batteries
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Bryan1 Guru  Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
G'Day Guy's, I have noticed these batteries are getting down in price. Now putting these in series for 24 volts and say getting 8 of them would get me a 1200AH 24 volt battery array. Also when I get to make the new Wiseguy inverter it will make it easier to switch to 48 volts too. As this would be my first venture into lithium do you guy's reckon this is a good idea or not. Some good advise would be really nice. Regards Bryan Edited 2024-03-13 13:32 by Bryan1 |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458 |
Hi Bryan a bit more information would help. What batteries are you referring to? 1200 amp hour seems like a big bank for lithium, as they are supposedly able to be deeper cycled than Lead acid. What is your daily usage in ampere hours? Are they LIFE PO4 or some other chemistry pete |
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| Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
G'Day Guy's, Well I went for look around town yesterday and saw a battery place where it really hit home why we are the ripoff country  of the world. For a 24 volt 300AH lithium battery a single battery $1776.00 + gst  So last night at work had a look at ali and what I reckon I found is these big lithium batteries are just filled up with 18650 batteries. Now if thats is the go why spend 5 figures just to get a decent batterybank where the same can be had with a 3 figure spend. These do look the goods and only 100 Chinese AH at 24 volts. Now if go and grab 12 off of these so we can either go 24 volts or 48 volts by different wiring. Now also with free shipping does make this tempting too. I have missed the boat so far with these 18650 cells and 7S3P to me says 7 in series by 3 parallel to make a 28 battery string. So by going 12 off of these packs we jump up to 336 18650's which should pack some punch. So yes a BMS will need to be made and a heap of 10K heat sensing chips and a few micros to do the reporting but it does look like a fun project to do. Cheers Bryan Edit: found the first did include shipping and in typical ali fashion found the same thing from a different vendor at half the price and free shipping. So for a total of $494.22 got 12 of these 29.4 volt 100 Chinese AH on the way expected mid May on the slow boat. Edited 2024-03-14 09:58 by Bryan1 |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458 |
I looked at the specs on those batteries, not sure why they quote 30 to 100 amp hours for the pack. Being used to Lead Acid batteries I find it hard to figure that they have fitted 100 amp hours into such a small package. Pete |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022 |
Hmmm....I've said it before, Don't buy batteries from Ali, Don't even waste your time looking there at batteries, even the advertising is wrong that should be a warning as it is. Oh and forget using 18650 cells for home storage. Check a few Australian local shops if there are any close by, yes there are more expensive, but you have a better chance at buying a battery instead of a brick. Here is my local shop down the list they have the specs for the 100ah cells, so you can work out what weight a 12v or 24volt setup should weigh. BWB I have bought the 206ah cells years ago and they work a treat, pity they have not dropped the price yet, but they might lower the price later in the year. Anyway it helps as a guide so you know what to look for. If you only wanted a 12v battery then a ready made one with BMS and terminals would be the way to go, 24v or 48v buy the cells and and wire in a suitable BMS. Hopefully prices drop soon, as they have done elsewhere. Footnote added 2024-03-15 22:13 by Revlac Bryan, somehow I missed it and had not read you Edit before I posted, happens sometimes.  Cheers Aaron Off The Grid |
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| Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
Hi Aaron yes I do remember you saying about this but I thought what the hell this is all about some fun as I missed the boat. Now I have been thinking about these lithium fires that can happen and would they still burn if no oxygen was present. I do have some old ones here so I'm thinking of making a cabinet putting the lithium battery in reverse voltage in a closed field of argon to see if it still burns. My crazy idea when these turn up is flatten some 1/2" copper pipe to make the busbars and just go 24 volts as that is my setup at the moment then use that inverter I made as the power. Connect my VAX a 2400 watt vacuum and monitor the voltage drop etc then hook them up to my solar just to see how they charge. Well the tesla battery is just a bunch of these cells and off watching vidoes years ago where a guy made his own tesla battery. He wired them in series to get around 360 volts off memory then used some electronics to convert it to 240 volts AC. So off my test off a lithium fire if argon can quell it I will be making a case for this test and have a dedicated argon bottle setup if things go south. Well yes $500 for the test won't end the world so why not have some fun testing these chinese batteries out  Regards Bryan |
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phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2134 |
The argon should prevent the fire spreading after the rupture. There are two issues with these cells. 1) An internal exothermic reaction fed by the stored energy heats the cell until the electrolyte boils and bursts it. 2) The electrolyte is a flammable hydrocarbon, released as a very hot gas. In air it burns like a blowtorch. Your case may need to be quite sturdy and airtight, with enough empty space to hold the gas without venting. |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022 |
I have run the house on a heap of little 18650 batteries for a few years without any real problems, didn't have any BMS or other equaliser, I just managed that myself. I did a topic on this, think it was called battery experience or something, it worked well I just don't encourage anyone else to do it. Most fires and blowups are from abuse and mistreatment, not all from the user, sometimes the electronics management stuffs it all up, seen it happen quite a few times. Like most things push it too hard and you can destroy it, just as well these high performance car engines have Rev limiters for those people with a lead foot.  Anyway experiment with it learn a bit along the way. Cheers Aaron Off The Grid |
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| Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
Hi Aaron I did a search and found that thread easily just using the search function on this forum Now with these packs I'm getting they do say there is a BMS on each pack so yes I will be opening one of the cells up to take a look at the BMS and take some photo's. Hopefully at Easter those 2 arrays of solar will be going on the roof so it will hopefully transform the house forklift battery just like those 6 off 190 watt panels did for my shed forklift battery. My wife thinks as soon as the genset is going she can put a heap of load on the battery like an electric cooker and the washing machine at the same time so the idea behind this bank is to take the battery charging off the house load and let these lithium cells run the house while the forklift battery charges. This will cut down the run time and save on a heap of fuel. Also on hot days this other battery can separately power an aircon taking the extra load of the forklift battery. Now at under $40 each for these packs if this first pack of 12 do work out alright more will be bought so with the extra loads put on the more packs to power the load will mean less current draw. Also hooking up for 48 volts will be a breeze so when Mike's inverter is finally made it can be tested using 48 volts. As I will have 3 separate solar array's all with MTTP's anyone can be used to charged this lithium pack so I will setup for that too. Looking at the tracking for these packs it's now saying late March for delivery and with me working nightshift time will fly and they will be here before I know it. Regards Bryan Edited 2024-03-16 13:00 by Bryan1 |
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Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 648 |
Opening a lithium battery pack is a bad idea, you might start a fire. I once opened a 200Ah lithium cell to see why it went open circuit. I was not long before the cell wrapping (wound like a capacitor) started to smoke and I had to spread everything on the lawn until the heat subsided. I appears that the electrolyte reacts with oxygen and produces heat - fire!. |
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| Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
What I meant by opening it up was just to take a look at the BMS NOT opening cell mate as that would mean one dead pack and a heap of mess  Had a look and it's saying still 2 days to ship out so it does look like they are a tad sloppy on getting off their butt to ship it. I have been looking around for a new DMM and I was looking at the Fluke range but the price did put off me off a instant purchase and while I was checking the Ali order came across this and for the price well it will do. Cheaper than any meter I can buy locally and eh if it does the job I'll be happy. Cheers Bryan |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022 |
Well the largest capacity of an 18650 cell (that I am aware of) is 3.6AH, so don 't know what they are selling, most likely lower than that 3 or 3.5AH, it will take a lot of them to make 100Ah at any voltage. Thats a nice little meter that one, be nice to see how well it works. My computer is stuffing up again. Cheers Aaron Off The Grid |
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| Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
Aaron if you want a cheap laptop I can find you one, the last one I bought was a Dell latitude 7400 W 32 gig of ram and a 500 gig of those new HD's just over $400 I'm sure there is new batch of them so if you want one just let me know Cheers Bryan |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022 |
Thanks Bryan, but I ordered another old Toshiba laptop yesterday, oh well I will look at those Dell's next time, thanks.  Cheers Aaron. Cheers Aaron Off The Grid |
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| Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
Well Guy's that meter dispashed on the day I ordered it so should be here in a week or so and finally those batteries have been shipped but no tracking info yet. So the work and wait still goes on. |
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| Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
Well that scope/meter turned up today and my only misgiving was I did see this unit also comes as 50mhz dual channel where the one I got is 10mhz single channel. Now my first thought was what battery is is going to take then after opening just turned it on and it came on. Now on RTFM it does have a 18650 single battery so plenty of power and recharging is via the Type-C usb to another device to charge. In DMM mode I reckon Roger would love this is does have a analogue meter aswell as the digital display in all modes. Got a heap of option for probes with a decent set for normal work and it does have a real fine point which would be good for smd. Also another set of probes and 2 sets of alligator clips with 2 sets of leads. Bang for buck I'm haapy with this unit as the ones I looked at down town under $100 were all cheap crap. Now this also have capture mode where it can save the pic to flash then transferred over via USB. The functions it does in DMM mode, voltage AC/DC, 10 amp current, diode/cap, frequency resistance/continuity and temperature. It does come with a temp probe too but for temp I'll fit the one I have here. Cheers Bryan Edited 2024-04-12 15:27 by Bryan1 |
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