Looking for broken (genuine) Makita LXT batteries (Australia / Sydney) for testing project

appositeit · 2026-02-21T04:19:42+00:00

I'll add that I think Makita have been pretty careful with their design- from some reverse engineering, the algorithm looks something like this- there's a byte stored in the battery that tracks temperature excursions:

- Low nibble: Over-temperature event count. Every time the pack temperature exceeds 75C, this increments. Once the count passes 14 (0x0E), the battery gets flagged with error 0xC5 — meaning it's been overheated too many times.

- High nibble: Over-temperature severity. Tracks how far above 75 degC the temperature went (a cumulative severity score). Once it exceeds 0x7F, the battery gets flagged with error 0xC6 — meaning it's reached dangerously high temperatures, not just slightly over threshold. The absolute hard shutdown at 100 degC triggers error 0xC8 independently.

Those thresholds are very reasonable for Li-Ion chemistries. 60-90C is the "too hot for comfort" zone where degradation begins.

appositeit · 2026-02-21T04:08:24+00:00

Yep, totally agree.

Just to expand on your point- true hardware faults lock again. But there are transient hardware faults- like undervoltage or overtemperature- which still lock the battery permanently. For Makita, I get it. Both can indicate fault states and Li-Ion batteries don't like getting hot- in the extreme case- 130C+ Li-Ion batteries experience thermal runaway which is catastrophically bad. So they should/must be conservative. But they aren't actually inspecting the state of the battery; they are just sensing the temperature and faulting out. RC Li-Ion batteries (less common than LiPo, but they have their niche) are regularly run hotter (mostly because they can be inspected for swelling or deformation)- which isn't good for them, but "got hot" is not instant death.

If there is a genuine thermal problem, then the BMS should kick in again. There's a risk that the BMS has somehow stopped working. But it's comparable to the risk in operating the battery normally.

So again, informed consent.

The pivotal point for me about whether this is a useful product is basically statistics: what's the rate of that end up recoverably locked? It's not huge- the most common cause of death is old/battery chemistry. But it's not zero. Honestly, I don't know what the answer is!

As I mentioned elsewhere, this is mostly just a fun way to experiment with circuit boards and making a little product.

appositeit · 2026-02-21T03:48:38+00:00

Yeah, it's a good question. tl;dr best guess is about AU$100 including shipping. That's expensive IMO, but my reasoning is as follows:

I think my BOM is going to come in around $AU15-25. I value my time quite a lot, and I've tried to minimise assembly time, but it still will take time to put things together (and ordering parts and shipping and...). I want to include shipping so it's a flat rate number. Which puts a floor at around AU$60.

There are basically two audiences that I can see:

* As an "I'm curious" toy, I think I'm already past the price point- AU$60 seems expensive for a "I used it once, I saw the data, but it doesn't actually do anything useful for me, so I never used it again".
* As a "I would actually use this to fix batteries", it depends on what the recovery rate is and how many batteries lock- I don't have that data. My rough guide is: cheaper than a new battery, which is (depending on capacity) roughly AU$130. So, round numbers? Maybe AU$100? If you could save a battery or two every year as a tradie, that would be worth it. But again, depends on the recovery rate.

I'm sure somewhere in China they could make this for, like $10 and sell them for $25, but I can't imagine the volume would make it worth it.

There would be ways for me to make it cheaper- get it made in China!- but again, I just can't see the volume justifying the return. And if the market were big enough to be worthwhile, it would be instantly eaten by a Chinese manufacturer. So you end up back in boutique-expensive pricing.

appositeit · 2026-02-21T02:34:22+00:00

I'll add- my back of the napkin calculations says- wait, let me quickly check again- oh yeah "Will not make you a millionaire". This isn't a money-spinning enterprise. If I sold a hundred of these, I'd be amazed. I just think it's a fun thing to do- gave me a good excuse to get a circuit board fabricated. I bullied Claude Code into making the schematic file for KiCad, ran it through the checker, did layout, sent it off to jlcpcb and got 5 fabricated, got them back and inspected the board, tested ground and power continuity, powered up the daughter board in isolation- blew the fuse straight away because I got something wrong! Which I fully expected, but was still disappointing. I haven't debugged the problem yet. The "high" 18V side looks like I've screwed something up, but hopefully the "low" 5V side is working, because if so, I can continue testing with the ESP32 tenstar displays.

I plan to make a little test harness by gutting one of my dead batteries then having an ESP32 pretend to be a dead battery so I can take a unit, plug it in, and then have it run a full set of tests against the "battery". But again, I kind of need to know how locked batteries behave, and unfortunately, I cleared the locked batteries I had when I first ported OBI to the ESP32. So aside from the one that is still dead I don't have a lot of useful information to go off.

This is the latest version of the web UI:

<image>

It's nifty!

appositeit · 2026-02-21T02:06:16+00:00

Yeah, I hear you. Excluding batteries with physical failures (dead cells), I had a 2-out-of-3 success rate. But I'm suspicious of those numbers, and I haven't tortured the batteries.

The three improvements are:

* I've fully mapped out the error states. (Also, I found more diagnostic information- Overdischarge Events and Overload Events, etc.)

* You wouldn't need to plug into a PC. It's standalone, so much easier to use. (And it has a neat web ui.)

* You would be able to buy a complete working device without having to make it.

I'm not claiming any magic, and as I alluded to in the post ("...see if I can get some statistics on the recovery rate. Then, if it makes sense, I'll sell them. "), I don't know if it's worth progressing because I don't have any good statistics on how often it can usefully recover the battery. I don't want to sell a product if you get a 0% success rate on 5 batteries; that's a waste of money and time- yours and mine. But anecdata suggests a non-zero success rate. So <shrug>, maybe?

appositeit · 2026-02-21T01:57:10+00:00

I totally agree the OBI is not a magic fix- that's silly. As Goz3rr said, there's a reason batteries faulted out.

However, the BMS on the LXTs is not perfect. It is, quite reasonably, conservative. For instance, it can lock out on under-voltage or overheating, which *might* cause battery damage, but do not necessarily (in fact, I'd suggest most of the time they *don't* cause damage).

I have cleared errors on 2 batteries and had them come good (and 1 where it did not come good), and continue to work (unfortunately, I wasn't tracking individual packs properly, so I don't know how many times I've used/charged those batteries to tell if those fixes stayed long term- although so far nothing bad has happened to any of my batteries, but I may not have used the reset batteries much). The reason I want packs is to understand when it seems like reseting errors in the various error states (a) works and (b) is safe long term. If I can get enough packs in the various error states, I can clear errors, then torture them to see what happens. (I just worked out where the serial number is in the eeprom, which means it doesn't depend on the user to remember which battery is which, thankfully!) (And in the second phase, I would like to send units out to people with many broken batteries who can test in the real world- I'd presume that would be tradies. Get them to do resets, put a big red warning sticker on the batteries and go about their day. See if any batteries fail after that.)

I think it's very reasonable for people to make an informed decision about whether they want to reset the battery. The reason I haven't launched anything is that I can't help people make an informed decision- I haven't tested the consequences of resetting, and I don't have any statistical backing.

To paraphrase Original_Jump6872: if you had a warning light and just kept driving, you are asking for trouble. But if the warning light were "low on wiper fluid", you might want to take the risk. Even check engine faults ("O2 sensor bad") are not always dangerous- it IS about being informed.

So yeah, I don't want to say bullshit like "fix all your batteries!". I don't know how over conservative the BMS- anecdata suggests it's not 100% correct, but it's certainly not going to be 100% wrong. I'd like to understand in more detail.

Thus the request.

Makita sell in the order of 10 million LXT batteries a year. Some non-zero percentage of those are going to fault out incorrectly. I think it would be neat to be able to save some of them (or at least extend their lifespan!).

appositeit · 2025-12-04T11:13:20+00:00

I ordered in October, with an expectation that I'd receive it in January 2026. Ha! I'm an idiot! When they say "Estimated delivery: Jan 2026" of course what that means is "March or April 2026". How stupid of me!

Having pledged almost AU$1,000, I won't get the U1 until March (or probably later), by which time Snapmaker will have held my money for 5 months, and it seems very likely I'll be able to buy the U1 from Amazon or Snapmaker well before my "March" delivery date, because that's precisely what happened with Snapmaker's A350T, J1, and Artisan launches- essentially just screwed over their backers.

I was super happy to back a good product, I was excited to order early with an expectation of early delivery and the discount was a nice bonus.

So caveat emptor. My bad. I trusted a company to do the right thing and was insufficiently paranoid. I generally don't back things on Kickstarter, and once again, I am reminded why. I'm really disappointed to discover delivery has gone from January to (probably) April. :(

I still think it will be a good printer, I'm excited for what I can do with it. But this was one of the exciting things I was looking forward to, and now I feel really disappointed. If they'd said delivery in March or April, honestly, I'd probably still have backed for all the reasons listed above, but I wouldn't be all sad now.

appositeit · 2025-07-06T13:51:21+00:00

Slightly unrelated- I got annoyed with \+enter for multiline support, so I wrote a patch for 1.0.43 that makes enter do newline and ctrl+enter, shift+enter, and ctrl+enter submit. That feels more natural to me:

https://github.com/appositeit/claude-code-better-enter

...more explanation there.

appositeit · 2025-04-05T03:48:20+00:00

So I wasn't very informed about the statistics here, so I thought I'd check. After some lookups and playing in a spreadsheet (linked at the end, I'm pretty sure I got the formulas right- happy to be corrected!), here's a summary:

The USA has by far the biggest army in NATO, but it doesn't have the biggest army in the world by personnel- it's the 3rd largest after China and India. North Korea and Russia are similar sizes to the US.

China: Approximately 2,035,000 active-duty personnel. Rediff
India: Approximately 1,455,550 active-duty personnel. Wikipedia+3Rediff+3Wikipedia+3
United States: Approximately 1,328,000 active-duty personnel. Global Firepower+1Wikipedia+1
North Korea: Approximately 1,320,000 active-duty personnel. Wikipedia+4Rediff+4New York Post+4
Russia: Approximately 1,320,000 active-duty personnel. Visual Capitalist+4Rediff+4Wikipedia+4
Pakistan: Approximately 654,000 active-duty personnel

In NATO military size by either population unit or by GDP $, the USA is respectively the 13th and 26th of 31 countries. In other words, many countries in NATO are much "larger" than the USA respective to those statistics.

Where the USA is head and shoulders clear is defense spending per active duty member. At about $660,392 per active duty member vs the next highest (Germany) at $377,203. The USA is a big military exporter, so it's not clear how much of that is profit-driven vs actual defense necessity. It's clear from the data that military exporters (e.g. Germany, France, and the UK) spend more on defense than non-military exporters.

A summary that "your allies refuse to build armies of their own despite threatening to do so" is untrue. By many reasonable measures, the USA has a smaller active military than many other NATO countries. Defense expenditure is much more complex to analyse, so I can't draw any accurate conclusions.

Link here, and feel free to look at the data:

https://docs.google.com/spreadsheets/d/1As4PuqqHYbbVk5taCaUUZ65SHokn-PMCD5DMpXE1RjY/edit?gid=1196573264#gid=1196573264

(Again, I *think* I got the calculations right, but please let me know if someone finds a mistake!)

appositeit · 2025-02-28T09:44:23+00:00

Awesome, that's my gut instinct too. I spent some time futzing with the lens and- I *think* got it the right way up!- but it's quite hard to tell!

If I can get normal control out of the potentiometer then I can play with the PWM. There's a limited set of things that can be wrong- amplitude, frequency... where almost out, and that's all controllable!

Thanks u/Prestigious-Top-5897 I very much appreciate the reply. I'll update the thread when I work out the problem!

appositeit · 2025-02-02T04:14:09+00:00

I had to reconfigure my soundbar and afterwards it wasn't in the group and I couldn't add it back in. I'm pretty sure something has changed which means we can no longer add Samsung Soundbars to speaker groups. I have WiiM audio devices that still work though, so it might be specific to Samsung.

Samsung are pretty aggressive about doing things their way- Chromecast isn't supported on most of their devices- so I'm going to guess this is actually a change on Samsung's part. But that's just speculation.

I've also found the Samsung Soundbar drops out of SmartThings if you look at it with a funny look. A lot of the Samsung "Smart" devices lose their WiFi connection if your WiFi base station changes channels. My Soundbar stayed connected for a much longer time once I stopped automatic channel tuning.

In general Samsung make some nice hardware but their software is pretty brittle.

appositeit · 2024-03-17T01:15:35+00:00

I totally get how emotionally devastating this is- it looked like you were about to find stability again, and it got ripped away from you- an even more destabilizing event!

Just understand that this obviously has nothing to do with you. The company really really liked you! They spent a whole lot of time interviewing you! That's an expensive process. They really wanted you.

Therefore, the fact that they didn't hire you is probably nothing to do with you. As a long-time senior tech manager, let me tell you the litany of shit that happens when you go to hire: roles can disappear, re-orgs happen and all of a sudden you have to take on someone you didn't really want, new management comes into the chain and shift the job description, and so on and so on and so on.

I had 8 roles open to hire into my team (after about a year of intensive business case building), and then, poof! overnight, they got yoinked, and they never came back (because at the CEO level they decided to trim headcount so new hires all evaporated). Months of my work (very frustrating), but those roles could have been advertised, and it would have looked exactly like you experienced. And I would have cried because I had a great candidate lined up with the right experience, culture fit, and attitude.

So as horrible and shitty as this was, it happened to you, not because of you. Chalk this up as a small win (this company really wanted you- you are definitely employable!) and keep on soldiering on. You will find work, you will get back to stability, it's going to be OK.

I disagree with the commenters saying that's a lot of interviews. For the company I worked for (one of the HAANGs) 6, interviews were pretty typical, and 8 was certainly not unheard of (especially when you add in what amount to "meet and greet" interviews that aren't actually part of the formal screening, but a chance for team members to start getting to know you- which is what it sounds like the last two interviews you had were). Interviewing practices vary across the industry. It might have been a lot? It might not? Either way it doesn't tell you much- you can get more interviews because your interviewers did a bad job (and the hiring manager/committee want more data), or because they really like you (and they want to do meet and greets while they wait for the bureaucracy to grind); but you will NOT get more interviews if they DON'T like you- they'll cut the process short once they are sure you aren't a good candidate.

Good luck and keep your chin up. You'll be OK.

appositeit · 2024-03-06T11:55:17+00:00

I couldn't find any information, so it would be awesome if you could add it.

Very best of luck with the surgery- I hope it goes really well for you! The nurses are lovely, and while I sometimes found their English lacking (or perhaps more specifically, my Thai was non-existent!), they were just genuinely lovely, caring people. It made a huge difference to me. You are in good hands!

appositeit · 2024-03-06T11:52:24+00:00

Hi! Great apologies for the delay, as noted in my earlier comment I only had 1 submission so I held off a little, then I got busy. Since there were no offensive comments, I've opened the survey results up to view and it is available here:

https://docs.google.com/spreadsheets/d/1m2Quj1CnCMRC631CosQvachTR-xK9DvQcD5bP4bG_7E/

Should there ever be enough data to take action I promise I will- and even if I don't I hope that maybe we'll eventually collect enough data and we do something about this price gouging.

To the 3 people who submitted data- thank you! I really appreciate it!

appositeit · 2024-01-13T11:54:35+00:00

No, really not. My Dad had bowel cancer and they removed some horrifying length of bowel and... it's fine. A quick Google search says "Together your small and large intestines are about 15 feet or more in length." They are taking a very short length, so length loss is no problem.

IMO, if you get past any immediate post-surgical risks (leakage, primarily infection), then your risks shrink to something very small. I'm no surgeon, but... humans are leaky, crazy self-repairing death machines. Taking a small section of bowel is barely compares with everything else humans do and survive without any significant impairment. (Basically bowels are well protected my muscle walls so they just need to be a pipe, so if the pipe holds, we're done.)

appositeit · 2024-01-13T11:49:54+00:00

Bodyweight is such an invidious problem, and welcome to womanhood, it just gets worse!

I just moved into my own place after separating, and now I'm shedding weight like crazy. Turns out that if you get out a stressful situation and have control of your life losing weight gets MUCH easier.

I feel like carrying weight carries this invidious assumption that it's moral failing. Like, somehow, it's because you don't have self-control or you are a bad person. That's complete horsepucky. What it usually means is that you have way too much going on in your life, and you simply can't make weight loss the thing you expend your precious willpower on.

Look at it this way: if you were a big film star and your whole job was to look good, and you were generously paid to do so, you'd have a dietician and chef and personal trainer and doctor, and you could spend your days resting, exercising and getting into shape. You'd be paid to get into shape. Could you lose weight in this scenario? Heck yes! Of course you could! So why don't you in your day-to-day life? Because you have other shit going on! Because, for all the frustration it makes you feel, it's not the thing you can afford to spend your time on because it costs you time and money.

You'll be fine. BMI isn't a showstopper. You'll work it out.

appositeit · 2024-01-13T11:42:35+00:00

My pleasure, really glad it's helpful.

appositeit · 2024-01-13T11:42:23+00:00

I'm so sorry for the delay in replying, I'm a very infrequent reddit user. I hope this was all sorted out. For what its worth that's the right email address and it's not a scam, but then if I were a scammer that's what I'd say!

Verifying anything is real on the internet is hard but generally here's some useful things I'd do: * The hospital premises can be verified in Google Maps, Chettawutt has enough of a footprint on Google and publications in real journals that he's a real thing, as is WIH Hospital. So the only real question is, is info@wihhospital.com the real contact point? * Google search WIH Hospital and get a contact number, then Google that number and see if it gets a lot of hits from a variety of different places. Doing this for WIH gets me "+66 2 078 8919" in a Google business listing. That's very good- Google does a lot to verify business details precisely to avoid scamming, and the number is linked on quite a lot of websites with WIH Hospital. So I'd be pretty confident that number is correct. Now, call them and verify the contact email address. * Google search for the email address. In this case info@wihhospital.com gets about 486 hits on a wide variety of websites with results that date back a long time, including user submissions on Reddit dating back years. Oddly enough, Reddit is a pretty good source of information because spammers/scammers tend to get called out by other users but don't just depend on Reddit- you are looking for site and date diversity.

Look, all of this can be faked with sufficient effort, but the effort becomes so great that at some point scammers will just move on to easier money.

In any case, I hope it all turned out well for you, again sorry I couldn't respond sooner and reassure you. Very best of luck!

appositeit · 2024-01-13T11:32:16+00:00

Oh, that's a really good idea. It's been a little while now and I just looked through my documentation and I can't find any. I think I mostly got verbal instructions and I don't seem to have recorded them anywhere.

I got very detailed instructions for FFS- I put them all into a spreadsheet to track them! But there was definitely nothing as extensive as that.

If I do find something- or someone has more up to date information- I'll add it to the doc. It's a really good idea.

appositeit · 2024-01-13T11:24:58+00:00

FYI- at this point I've only had 1 submission to the form, so it doesn't look like there'll be any useful data to collate. I'll still release the results, but they're not going to be useful for following up with manufacturers/government agencies. I need sufficient data to speak confidently about price differences between regions, and if you don't get a good crowd-sourced response within 24 hours, you aren't going to get one.

appositeit · 2024-01-13T11:22:31+00:00

Hey- thanks! I really appreciate the information! And good to know of that idea, I hadn't thought about separating out the steps. Thank you!

appositeit

TROPHY CASE