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Anonymous05/18/25, 19:15No.2917864Battery general (?)
Would anybody be interested in a thread all about batteries, battery tech/chemistry, cells, building your own packs or scavenging cells from old packs, making your own chargers, etc?
I'll start off in the next post.
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Anon05/18/25, 19:36No.2917867
In an ideal world, wouldn't it be best to have the charge controller able to measure the voltage of each cell individually, no matter how many cells you have, how many are in series, how many are in parallel, etc? If I'm using an arduino or something to monitor voltage and control charging the main limitation would seem to be the number of pins available. I know there are multiplexing chips you can use to let you control as many power transistors as you want, but is there something similar with analog measurements?
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Anon05/18/25, 19:48No.2917871
Another stupid idea I had involves using a shit ton of buck/boost converters and basically hook each one up to its own cell or maybe a few cells in in series rather than having each cell/group of cells in parallel with each other. My thinking here is that if you have a bunch of cells in varying states of health, you can still use them all together because when one group's voltage drops out earlier than the others, it just stops supplying power while the others take up the slack. Basically it might let you use mostly dead cells with halfway decent ones, just to squeeze out the last bit of life from a cell before it gets decommissioned.
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Anon05/18/25, 21:20No.2917889
Still Looking for a High Amp Hour LiFePo4 Battery for my Solar Setup.Any recommendations or Am I Looking at Connecting Panasonic 18650s together and Buying a Spot Welder?
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Anon05/18/25, 21:59No.2917900
Where my Na-ion bros at?
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Anon05/19/25, 00:12No.2917933
I would like a battery thread yeah. Could use some chargable aa/aaa recommendations, but I really need a chargeable flashlight with a battery that isn't complete dogshit and preferably not maglite hueg.
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Anon05/19/25, 04:04No.2917997
I'm in the market for LiFePO4. I have zero interest in building one. I want plug and play with UL certification.I'm 90% set on Trophy. they have BMS & built in heaters. our batteries & control system are mounted in a shed we built, with panels mounted on tip. its aboot 18m away from the house, not heated and not well insulated.we currently have 8X Trojan T-1275 FLA S/P to 48v for 300AH. however, at 50% DOD that's only 150ah usable. the trophy is rated 300AH at 90% DOD, but it tests closer to 310AH. I have taken good care of my Trojans, but they are 4 years old. I am planning ahead.massive financial gut punch, but it would more than double our storage.
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Anon05/19/25, 21:13No.2918175
is there some good battery store in the EU? Im looking for some battery with a JST 1.25 connector.Also what the fuck is everybody smoking where the same connector has thirty names and why are there so many in general?
Oh yes i bet the .25 mm smaller one needs a new standard and multiple names.
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Anon05/20/25, 05:07No.2918259
Didn’t see this thread, got a battery full of waterGoing to dry this out and then seal it back up, can I just silicone it all back up or should the casing be vented for heat/gasses? (The reason it was full of water was it wasn’t water/airtight from factory)
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Anon05/20/25, 18:43No.2918370
If we're going to have some kind of battery general, can we get a FAQ about batteries?I want to learn about batteries and don't really know where to start.
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Anon05/20/25, 19:49No.2918379
Oh, I have another 2 little projects that might be of interest.The first is a DIY spot welder. In it's current iteration I have 20x 3000 mF 25V electrolytic capacitors all wired in parallel. I started out with just 10 but early tests made me think it needed a little more juice. I also bought an additional 50x 1000 mF 25V caps that I can install as well if I need to. I have 2 prongs of solid copper wire (I think 16 or 18 gauge) connected to some stranded wire to act as probes. I talked to a retired EE and he suggested I might try using some TIG welding tungsten instead of copper because it would be considerably less ablative. I haven't actually tried welding anything to a cell yet, so far I've just been testing it by welding nickle strips together, which it seems able to do. Sometimes it doesn't get enough heat, and sometimes it blows a hole in it. I think part of it is the technique.The other is a very stupid/fun project. I'm making an external battery for my laptop using a bunch of Ni-MH AA cells. I've got a total of 64 cells in the current version. It's got 8 cell series holders that are wired together so that there's 2 sets of 4 in parallel and then those 2 sets are in series, then a buck/boost converter with an adjustable input voltage cutoff to dial it up to the 19.5V or 20V that most of my laptops take. I cut the end off of a broken charger or a cheap knockoff one from ebay and solder that onto the output of the converter. I've tested it briefly and it does seem to work, but I haven't tried testing how long it will actually last. The thing that I think is really funny is that the computer thinks it's plugged into AC power. When depleted the idea is to pop all the cells out and recharge them in a regular AA charger.I'll have to post pics of these.
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Anon05/20/25, 20:44No.2918395
Was reading about molten salt batteries that are usually only user for short term power, usually in military equipment. Super low internal resistance. Id really like to make one simply as a balls to the wall performance battery for a bike or “e-dragster” They are basic in theory, dissimilar metal anode and cathode separated by a low melting point salt - like around 3-400c. Its probably not that easy, but I wonder if aluminum and iron foil would be suitable materials, and most designs were triggered with pyrotechnics. Even if it only lasted for 15minutes but powred a comically large dc motor.
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Anon05/21/25, 10:37No.2918573
Scavenged this off a vape that took a dip in the washing machine. Unlike its friend this one still has 2v so i guess the water didn't kill it. It looks like a cap but searching for the numbers returns suggestions for lithium stuff and from what i know vapes do not use caps so does anyone know if this is a lithium battery in capacitor format or if its actually a capacitor?
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Anon05/21/25, 15:02No.2918624
I harvested 18 18650s out of some old laptops, all of them were sitting at <2.2v for God knows how long. would you trust these? I know LiPo's can grow dendrites and go suicidal at random after going below 3.0v, do Li-Ion cells share that property?
I want to make some very light duty 4-6s 1p packs out of them.
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Anon05/21/25, 19:11No.2918675
> range of 30-60mV
Your argument seems to be based on either the insignificance or undetectability of voltage drops in the mV range.
But consider the typical current shunt used in the 10 A range of a multimeter: it measures the voltage drop across a 1 inch piece of circular 14 awg copper wire… pretty standard since the 70s or 80s.Why you have a hyper-religious zealotry for advocating:
- the unnecessary over-paralleling of cells
- not monitoring them
- drawing unnecessarily high currents from themis beyond me, unless you work for the li-ion industry and/or big copper, or both.
I’m just here pointing out a few things. If you’re DIYing your own packs, I try and put some basic safety ideas into practice not cut every conceivable
cost in a mass production scenario.Yeah, tesla had a ridiculous 18650 pack, but they knew they didn’t know what they were doing and mitigated accordingly. Do likewise.
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Anon05/23/25, 23:32No.2919152
I want to convert this auto/dent removal spot welder to make batteries with. I got it for $80 and seems to work fine.I think i need to do the following tasks:
1) Replace the leads
2) Attach handpiece
3) Get handpiece to trigger the weldI got one of these: https://www.amazon.com/Shkalacar-Integrated-Welding-Automatic-Accessory/dp/B09BFQ7HC3/I realize I'm not sure how the triggering works. Before I start taking shit apart, anyone have suggestions on this project?
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Anon05/24/25, 01:15No.2919169
When it comes to supercapacitors vs regular electrolytic capacitors, is there any downside to supercaps other than lower voltage? (I'm not talking about the hybrid lithium ones that need to be kept above a given voltage, just regular supercapacitors)Like can supercaps discharge as fast as electrolytic ones? That's the main thing I'm interested in, the ability for it to dump as many amps as the rest of the circuit it connects to will allow with resistance and all that.
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Anon05/24/25, 12:07No.2919264
watch your loose wires. I just wondered why my little battery got so got. Dropped it into undervolted territory with no way to charge it right now.
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Anon05/27/25, 21:20No.2920130
lifepo4 is cool. I put them in my 3.3V arduino sensor projects. Better suited than the common 14500/18650 lithium-ion and 2xNIMH.
Comes in 14500 size.
No step down regulator required.
A side effect I didn't realize is sub-Ghz radio modules like more volts. Better transmission power than NIMH gives.
A sweet spot between the two common battery types.
thanks for reading my blog. like and subscribe.
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Anon05/29/25, 21:23No.2920606
what is the least painful way to bring ~300 cells to the same voltage before i assemble the battery. i dont have much money...
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Anon06/10/25, 08:50No.2923182
I heard a theory about bricks being used as batteries
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Anon06/10/25, 16:35No.2923236
Hiw much battery need for making of weld portable?? I make metal trash together and batter sparks but better
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Anon06/16/25, 12:15No.2924455
What's the cheapest rechargable 24V battery solution?
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Anon06/21/25, 07:16No.2925560
Why the FUCK does no DC-DC charger modules exist on aliexpress?>can get plug-in charger for regular sockets that work with batteries that have built-in BMS's
>can get BMS/charging hybrid boards for soldering myself
>can't get charging boards that works as a charger but can be supplied with like 24VDC
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Anon06/24/25, 07:30No.2926322
Hell yeah. I'm pretty sure I hooked this up right in parallel but I might have welded a wrench to the ports. I don't know how that's possible without electricuting me but I tried. Believe me I tried to avoid getting electrucuted I hate that shit.
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Anon06/24/25, 11:39No.2926354
I have an old laptop with dead battery
it's Asus K55VD, battery is A32-K55
I'm thinking of opening it and swapping those six 18650 pattern li-ion cells with newer ones, but probelm is it has some texas instruments BMS chip on it
is there any DIY way to reset the BMS at home with minimal tools or tricks? I have heard sometimes shorting battery bank positive terminal to BMS' positive terminal may reset it
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Anon06/29/25, 20:19No.2927652
any recomendations on cells for a 12v powertool battery?
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Anon07/04/25, 18:31No.2928984
I want a portable 120v power source
I wish to power an Ikea Eneby 30 speaker
I read that it draws 40W, I don't think I have the means to test that
There are $100-$200 units readily available, and I might ultimately go that route, but this seems like it could be a fun project.If I could insulate/protect everything, do you suppose I could just hack apart a cheap car inverter and connect it to a SLA battery?I might grab a SLA charger and wire up a double-pole double-throw switch so the battery can only be connected to input or output and not both.Going to keep researching, please point out any glaring retardation or areas for improvement.
Thanks, have a blessed day
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Anon07/18/25, 22:21No.2932456
what kinda cells do drone batteries have
is it worth buying rechargable aa and aaa's for shit that costs less than them
can you roll your own zinc batteries like blunt
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Anon07/22/25, 15:57No.2933310
Any good resources for making use of the batteries from those vapes people throw away? Thinking power banks, solar charging etc
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Anon07/24/25, 00:08No.2933720
How do I tell if a lithium battery is still good?I have one in my motorcycle and am curious about it possibly being bad. It has a button on top that you press and it'll illuminate a light indicating what percentage the battery is charged to. It totally died while riding and I had to have it trailered home. I replaced the stator because I thought it was bad, but I don't think it actually was. When I charge the battery with my tender, it won't go past 60% indicated by the lights on top. It used to charge to 100% but now won't no matter how long I leave it charging. My bike is charging as it should, but I don't want to ride it too far in case it dies again. I'd rather not drop like $200 on a battery that'll fit in my bike unless I'm sure it's bad.
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Anon07/28/25, 04:17No.2934780
I got sick of my bluetooth speaker not being able to hold charge well, barely lasting more than 30 minutes and took it apart today thinking it was only powered by a single 18650, was surprised it had a 4 pack of them. I'm not sure if 7.4v 3600mah isn't enough to power a big speaker for long or it's just the shit batteries it came with. What are my options for moar capacity? All I see for replacements are from Aliexpress and Alibaba and I know not to waste my time and money with cheap chinese sites. I tried looking for a similar pack with 21700 batteries but they don't exist.
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Anon08/02/25, 22:02No.2935869
You can get a ton of frewbies through old vapes
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Anon08/08/25, 20:04No.2937151
>put lithium batteries in series
>they light on fire
just buy a battery case desu
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Anon08/10/25, 20:44No.2937550
Is it better to buy 4 low Ah batteries rather than 2 high Ah batteries for a 2x18V high discharge power tool? Cell numbers stays the same but the energy density changes.Low energy dense cells gives you more charge cycles and the batteries run less hot when you switch the packs half way through the job. They are also rated for higher discharge amps. Two sets of batteries gives you the benefit of charging the other set while you are using the tool to keep going. In the other hand two high Ah batteries are cheaper than buying 4 lower Ah batteries.
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Anon08/12/25, 02:26No.2937797
I'm refurbering a razor e90 scoot-scoot. I was going to put a "12.8v" LiFePo4 battery in it but the charging situation is frustrating. I'm not trying to buy a dedicated charger until I know its going to stay running. Can I use pic related in the meantime? It has a voltage cut off and the battery itself has built in BMS. From my googling it should be good but most of the info I found was solar related so not quite what I was looking for.
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Anon08/16/25, 16:59No.2938578
do you know anything about early 1900's acid batteries? My grandpa mentioned some electric setup they had in the Poconos in the 30's where they poured acid into it every day
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Anon08/17/25, 16:56No.2938825
Anything i need to take into consideration if i want to run multiple bms boards in parallel? 3 in total for each series group.
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Anon08/27/25, 01:38No.2941071
batts from old laptop. the one on the left still has 3.4v and the ones on the right have low voltage but twhen i measured resistance it read below 50, but it ramped up. should i reuse them or just buy new LiPO4. im tempted to make a UPS for my cctv and routerhttps://www.youtube.com/watch?v=KQW-hUJ49eM&list=PLE7E5EMjOqksr1tOfCBecJuFP-nHI0-Nv
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Anon08/27/25, 02:25No.2941080
im using my mini lifepo4 ups to charge the old li battery, ive checked the charging voltage is 4v, matches the reading when plugged in. wish me luck
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Anon08/27/25, 17:21No.2941211
Onetime I nearly ordered one of those special battery tab welding machines.
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Anon08/29/25, 22:45No.2941717
How can I get something like this to work?
Long story short, I often find myself doing small events, I have access to lots of these dewalt branded batteries I can borrow from work, so I wonder if there is a simple way to rig a bunch of PAR rgb lights to them - they are great for ambience, just point a few to surrounding trees and it makes everything much bigger and cooler looking but running mains power to ten plus lights which are spaced all around is a pain in the ass sometimes. So here are few questions:Would the lights drain the batteries too quickly? Ideal setup would be one light per battery that lasts at 4+ hours at full brightness. If its doable how would I go about setting this kind of thing up? Oh and I wonder if the dewalt is too apple-cucked so they would have some kind of locking chip in them that talks only to their tools.
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Anon08/31/25, 22:05No.2942110
when i look for DIY UPS for like a small powered device(cctv,router,etc) its always Li ion or LiFePo4. but i have an unused SLA battery lying around, and i couldnt find a how-to
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Anon08/31/25, 23:19No.2942123
this looks simple enough for a retard like me, opinions?
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Anon09/03/25, 20:38No.2942746
I got ultrafire batteries that ran put after an hour powering a little hobby servo. I know theyre bad but just how bad are they compared to say samsung batteries.
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Anon09/24/25, 08:51No.2946692
What do I need to study and understand and what practical skills do I need to make replacement batteries for old ThinkPads? What more would I need to learn to add USB-C charging ports to the swappable batteries and, ideally, allow them to function as power banks for other devices? If you can outline a curriculum I will save it and work through it over the next year or two (or longer, if necessary). I am a pipefitter and my understanding of electronics and electricity currently doesn't go further than a general notion that wires are pipes for magic.Partly in service towards this end I intend to set up an electronics workbench in either my garage or my shed. Do you have any advice regarding this?
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Anon09/25/25, 09:42No.2946902
this is what im planning to do. i think im still missing some parts (diodes etc) and i dont know where to put them
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Anon09/25/25, 17:37No.2946983
>Most of the welders I've seen have four to six MOSFET devices in parallel to handle the current.Isn't there something with putting them in parallel that can cause them to blow up though? I remember watching an electroboom video somewhat recently and his mosfets kept blowing up because they weren't matched close enough or something, and either some kind of feedback loop developed or one responds before the others and takes ALL the current or something annoying like that...
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Anon09/25/25, 17:45No.2946986
regular link:
https://www.aliexpress.us/item/3256808137990797.html
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Anon09/25/25, 21:08No.2947022
The led is not working and the charger stays green so it does not seem to be working either yet the impact hammer still runs with this battery, any idea why did this cunt go dark on me?
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Anon09/28/25, 22:17No.2947639
well, fuck. i added rainwater to cells and charged it 4 cells had overflown and shorted. might be dead?
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Anon10/06/25, 19:54No.2949256
Does bosch, Makita, hilti etc repair their batteries or are they seen as disposable?
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Anon10/10/25, 21:37No.2950076
I bought these bad motherfuckers 10 days ago & installed them last Saturday. replaced our 4 year old, 300Ah (150Ah usable) Flooded Lead Acid batteries with them. now we have 15,000Wh (300Ah usable) with 95% round trip efficiency, faster charging & high discharge capable. built-in heaters (gets down to -15°C here) built-in BMS, closed-loop coms with our inverter, wifi communication via app & 10 year warranty. I will buy more as we can afford. probably 1 or 2 each year, until we have 6 or 8 total.
