#linuxcnc Logs

Nov 15 2025

02:03 AM Deejay: moin
09:46 PM roycroft: i'm sorry
09:46 PM roycroft: i should never have told you about multifix
09:46 PM roycroft: that is now going to cost you a bunch of money
09:50 PM lcnc-relay: <Lesliet@> rofl
09:51 PM lcnc-relay: <Lesliet@> _big anime eyes_ but.... so repeatable....
10:37 PM xxcoder: watched a video of guy talking about one penny deals scam on temu app lol
10:37 PM xxcoder: I do buy from temu, but never ever by app. only website
10:38 PM fluffywolf: lol, I was ranting about temu last night.
10:39 PM xxcoder: and recording of phone on temu app screen, dang I couldnt even tolerate that for a whole minute.
10:39 PM fluffywolf: I ordered from them for the first time yesterday morning... they had something I wanted for $200 less than amazon, and let me pay with paypal, unlike amazon.
10:39 PM fluffywolf: it was one of the most horrible shopping experiences of my life, and I have no idea why anyone would ever volntarily use temu.
10:40 PM xxcoder: honestly most of stuff I bought from temu is weird stuff. few useful stuff
10:41 PM fluffywolf: search results are 95% ads and 5% what you searched for, you get popups every 15 seconds on every single page including the shopping cart, they send you spam emails every hour, they're constantly pushing "games" that are studies in creating addiction that would make most casinos envious, every single thing they tell you is a blatant lie (you have a free item, etc),...
10:42 PM xxcoder: really? I dont get that at all
10:42 PM xxcoder: probably noscript and ublock orgin
10:42 PM fluffywolf: coupons aren't what they say they are - they're chances to win the thing the coupon says, if you play games or do tasks (like send referrals),...
10:42 PM fluffywolf: I used the app to get the extra $50 discount only available in the app.
10:42 PM fluffywolf: ... and then uninstalled it less than five minutes after completing checkout.
10:43 PM xxcoder: thats 4 more minutes than I would be able to stand lol
10:45 PM fluffywolf: you can google for reports from people who play the games... they're apparently all scams. I didn't try them.
10:45 PM xxcoder: honestly I am not surpised at all
10:45 PM xxcoder: just glad they dont do that crap on website. website sucks, but not that kind of suck
10:47 PM fluffywolf: https://www.temu.com/goods.html?_bg_fs=1&goods_id=601102793139399&sku_id=17606431786018 I got some of these.
10:48 PM fluffywolf: (note that I had to delete 3/4ths of the url to get that link, as the rest was obvious tracking crap...)
10:48 PM fluffywolf: they're $309 on amazon, and the app gave another $50 off... and I could use paypal with temu.
10:49 PM xxcoder: not too bad but how do you know its not half sand?
10:49 PM xxcoder: "TTemu just ordered this for me without my consent and has continually trying to withdraw funds and racking up over draft charges. they will not accept a return and had to put a block on my account to stop them . The question they don't seem to understand is why would I charge a 287$ item with 50 $ in my account."
10:49 PM xxcoder: ow
10:50 PM fluffywolf: they've been being tested by various youtubers and getting praised, and are currently will prowse's suggestion for budget batteries.
10:51 PM xxcoder: not too bad then
10:51 PM fluffywolf: the cells you get are a fun surprise, like all other budget china batteries, but everyone has said the construction quality is excellent and the bms is a decent unit that actually does 200A continually and actually has all the protections it claims to have.
10:51 PM xxcoder: wonder if I can upgrade my ups to use those lol
10:51 PM fluffywolf: could be 280Ah, 305Ah, or 314Ah, from EVE, CATL, or Trina...
10:52 PM xxcoder: it uses 2 12v 10a lifepo4 now
10:52 PM fluffywolf: if it's working with lifepo4 now, I can't imagine why it wouldn't work...
10:52 PM xxcoder: its rated to 1500ah
10:53 PM xxcoder: but lifepo4 cant go that far up apparently, with 2 batteries its just 240w
10:53 PM xxcoder: in least thats how that guy explained it to me
10:53 PM fluffywolf: those units don't make any sense.
10:54 PM xxcoder: err va I meant
10:54 PM xxcoder: Power Rating: 1500 VA / 1000 W model CP1500PFCLCDa
10:55 PM fluffywolf: then you'd need batteries that can put out 2000W...
10:56 PM xxcoder: I still cant understand that 2x 12v 9a lead acid can meet this ups requirement and 12a 10a lifepo4 cant
10:58 PM fluffywolf: lead-acid has very high power density.
10:58 PM xxcoder: yeah thats what I dont understand, power density
10:58 PM fluffywolf: the little battery in your car is putting out several kW while cranking.
10:59 PM xxcoder: anyway yeah im too afraid to try change things lol I dont understand it well enough
10:59 PM fluffywolf: power density is how much power, watts, you can get from a given size or weight. energy density is how much total energy, watt hours, you can get from a size or weight. lead-acid has great power density, but poor energy density.
11:00 PM fluffywolf: that is, they're bulky and heavy for how much energy they store, but they can put out that energy very quickly.
11:01 PM xxcoder: hmm ok thanks. I think I have vague idea, which is much better
11:01 PM xxcoder: would I be able to say, replace 2 12v 10a batteries with 1 24v 300a battery?
11:01 PM xxcoder: I dont know if can just use single 12v 300a
11:02 PM fluffywolf: if you have a 24V UPS, which would be typical for a UPS in that power range, then you would need a 24V battery, or two 12V batteries in series.
11:02 PM xxcoder: does amp matter, besides bigger=better?
11:03 PM fluffywolf: as long as it's enough, it doesn't matter.
11:03 PM xxcoder: how much amps would I need to meet 1500va/1000w?
11:03 PM xxcoder: assuming stay 24v
11:03 PM fluffywolf: at 24V, you'd need about 80A to get the full power of the UPS.
11:03 PM fluffywolf: 24V isn't something you get to pick. the ups only works on its design battery voltage. lol
11:04 PM xxcoder: lol yeah I meant stay with same device
11:04 PM xxcoder: series/parallel work to increase amps?
11:04 PM fluffywolf: series increases volts, parallel increases amps
11:04 PM xxcoder: if I recall ups has 2 batteries in serial
11:05 PM fluffywolf: that's usual.
11:05 PM xxcoder: im not sure about if battery 10a means overall current crossing it, or just how much specific battry can
11:05 PM xxcoder: sorry I know my questions is pretty bad
11:05 PM fluffywolf: batteries in series all have the same current going through them.
11:06 PM xxcoder: I know. I meant for parallel increasing amps
11:06 PM xxcoder: would lifepo4 have upper limit to amps or?
11:06 PM fluffywolf: lifepo4 has two upper limits to amps - the design of the cells, and the design of the BMS. *all* lifepo4 batteries have a BMS, and it has a current rating.
11:07 PM xxcoder: hmm ok. I do want to have big ups evenually for my home
11:07 PM fluffywolf: you can put a huge BMS on tiny cells, and you'll cook the cells before the bms shuts off. but pre-made batteries usually size the bms appropriately to the cells.
11:08 PM xxcoder: and somehow getting my ups up from 240w to say 400w which is well above what my pc usually goes around. usual is 40w to 100w
11:08 PM fluffywolf: if you exceed the bms's rating, the battery will shut down.
11:08 PM xxcoder: so its better to overate batteries than bms?
11:08 PM fluffywolf: if you buy pre-assembled batteries, rather than DIYing them, they'll give you a single number for the continuous discharge current, that you can use for planning.
11:09 PM xxcoder: honestly I rather have someone setup it for me than do myself but expense eh
11:09 PM fluffywolf: the bms is an internal part of the battery; you don't pick it yourself unless you're building your own batteries.
11:10 PM xxcoder: I saw in videos some people setting bms on large battery packs
11:10 PM fluffywolf: you should make sure the battery has a current rating more than your load, with some margin. so if your ups pulls 80A, you should get a battery rated for 100A or more.
11:10 PM xxcoder: 12v 100a seems to be around 100 bucks
11:11 PM fluffywolf: note that the current rating, in amps, is not the same as the capacity rating, in amp hours. a 100 amp hour (Ah) battery may have a 50A rating to a 200A rating or so, depending on what cells and bms they use.
11:11 PM fluffywolf: the 300Ah batteries I ordered yesterday have a 200A rating.
11:12 PM xxcoder: 1280Wh Energy Output: The 12V 100Ah LiFePO4 battery has a maximum output power of 1280Wh
11:13 PM xxcoder: picked random amazon entry of 12v 100a
11:13 PM fluffywolf: that tells you how much energy it stores, not the current limit.
11:13 PM fluffywolf: url to battery?
11:13 PM xxcoder: https://www.amazon.com/LiFePO4-Lithium-Low-Temp-Protection-Rechargeable/dp/B0FN7YLXJQ
11:14 PM xxcoder: trying to find max output but not too clear
11:14 PM fluffywolf: title says "Built-in 100A BMS", so 100A.
11:15 PM xxcoder: so 24v 100a so 2400w or am I very wrong?
11:15 PM fluffywolf: note that budget chinese batteries can be _very bad_. the Dumfume ones I got have decent test results and every has been happy with their construction... this is not true for most others. check for reviews and tests for unknown brands.
11:15 PM fluffywolf: that's correct.
11:15 PM xxcoder: ya just picked random battery for understanding
11:15 PM fluffywolf: s/every/everyone
11:16 PM xxcoder: 50a seem to exist, but not 100a
11:16 PM xxcoder: er 60
11:17 PM fluffywolf: "The maximum continuous discharge current is 100A" per the description.
11:18 PM xxcoder: random 50a https://www.amazon.com/HAYAEnergy-Lithium-Battery-Rechargeable-Applications/dp/B0C6QB8RG1?th=1
11:18 PM xxcoder: 24v 50a would be 1200w
11:18 PM xxcoder: still over rating of my ups of 1000w
11:19 PM fluffywolf: I assume your current setup shuts off if you try pulling full power from it?
11:19 PM fluffywolf: you need to take into account ups efficiency (probably 80%ish) and peak/startup loads.... don't size the battery just barely over what the ups can do.
11:19 PM xxcoder: probably? though I only use like 50-100w usually
11:20 PM fluffywolf: I wouldn't use less than a 100A battery on a 1500VA ups.
11:20 PM xxcoder: 5 % (50 Watts / 67 VA) sample right when I look at my ups website
11:21 PM xxcoder: one thing I wonder is wire connectors lol. current its spade type, and I guess I would need to change stuff to connect to 50a, or 100a batteries
11:21 PM fluffywolf: cheaper upses might be fudging their ratings a bit...
11:21 PM xxcoder: yeah. thats why I got good one
11:21 PM xxcoder: cyberpower
11:22 PM fluffywolf: little push connectors are not going to handle 50A very long...
11:22 PM fluffywolf: one way they fudge ratings is "the battery won't last long enough for everything to heat up too hot".
11:22 PM xxcoder: CP1500PFCLCDa cyberpower business. I guess "a" is hw revision
11:23 PM fluffywolf: i.e. they undersize things knowing the battery will run flat before the things have time to melt.
11:23 PM xxcoder: someday I want to buy used double conversion and use lifepo4
11:23 PM fluffywolf: double conversion means you use 25% more power and your electric bill goes up.
11:24 PM xxcoder: I know its pretty lossy but 25%? wow
11:24 PM fluffywolf: I just picked a number. new ones might be better. I know the old ones were good at keeping the room warm. lol
11:24 PM xxcoder: lol
11:25 PM xxcoder: https://www.ebay.com/itm/165668236181 one I was considering
11:27 PM fluffywolf: https://www.se.com/us/en/products-efficiency-graph/SRT1500XLA/apc-smartups-online-1500va-tower-120v-6x-515r-nema-outlets-smartslot-extended-runtime-w-o-rail-kit/ efficiency of a new $$$$ apc double-conversion. not bad, not great.
11:27 PM fluffywolf: so only 10% extra power, as long as you use it at more than half capacity.
11:27 PM xxcoder: 90% above 10%
11:27 PM xxcoder: ehh
11:27 PM xxcoder: I would mostly be at under 10% so it'd be nice and warm
11:28 PM fluffywolf: 10% is 77% efficiency on that graph.
11:29 PM xxcoder: I guess a way to recover some of it, is using it to recharge a big house ups while using computer
11:30 PM xxcoder: then discharge house ups while high power peak
11:30 PM fluffywolf: ... huh?
11:31 PM xxcoder: meh I guess PFC Sinewave Line is good enough for me lol
11:31 PM xxcoder: PFC Sinewave Line Interactive that is
11:32 PM xxcoder: if I had house ups I guess I wouldnt need smaller ups too lol
11:34 PM fluffywolf: bbl... got to get to bed. work tomorrow.
11:34 PM xxcoder: night and thanks
11:41 PM xxcoder: I wondered so I calculated 1000w/24v and got 41a. thats a lot
11:41 PM xxcoder: I recall something related to multipers for lead acid
11:42 PM xxcoder: according to my late night math, multipler is 4.6 or so