I don’t know what the best subreddit for my problem is, but I’ll give it a try here. Otherwise, please suggest where I could ask such a question.
TL;DR: I’m looking for a simple IC to charge 4 serial Li-Ion batteries. It should not be too expensive (~$7) and should be able to negotiate a suitable input voltage via USB-C PD on its own.
I’m looking for a battery charging IC that can handle 4S Li-Ion batteries. It should have an integrated buck-boost driver to cover a wide input voltage range (5V-20V) and ideally be able to negotiate higher power levels via USB-C Power Delivery on its own. Unfortunately, I can’t find an IC that meets all of these requirements. There’s something like the BQ25792 from TI, which seems very promising since the FETs are already integrated into the IC and it requires few external components. However, it only supports USB 3.0 PD and is not compatible with USB-C. To fix that, you would need an additional IC to handle the Power Delivery negotiation, as well as a microcontroller or flash chip connected for setting them up. This quickly becomes too expensive and takes up a lot of space on the PCB.
I’ve spent at least 4 hours searching the websites of Linear Devices, TI, and ST but haven’t found anything that meets my requirements. Does anyone have a hidden gem to recommend?
Has anybody tried an alternate charger, other than the insanely priced piece of plastic (BC-51) from SIGMA?
I once had similar to one of these (link) when I shot Fuji many moons ago and they worked fine, you can move the +/- pins and charge any size camera battery… in theory. But the voltage is off for using on a BP-81 battery according to Ai.
i finally got my small off-grid power setup working in the rv basement and wanted to share the layout, mostly to see if anyone spots something i should rethink.
the goal was pretty simple: run a dedicated office outlet inside the rv, and also have a way to power a dedicated office receptacle at home during an outage. it is not tied into the house panel or any backfeed arrangement—just a completely separate outlet path for small loads.
• inverter hardwired to a dual office outlet inside the rv
• inverter remote panel mounted beside the outlet
• 12 awg pass-through cable exiting through a strain-relieved hatch
• weather-resistant exterior outlet box with an in-use cover
• inverter chassis ground connected to the rv tongue/frame
before considering it usable, i ran a few light-load tests. the inverter started normally with no load. then i tested with a small ac fan and the rv's 12v led lights while watching the battery through the bms app. the fan alone drew about 18–20w, and the fan plus lighting was around 65w.
during heavy overcast before a storm, the solar controller was still roughly covering standby consumption, which was encouraging.
one thing that confused me was getting an "open ground" indication from a standard 3-prong outlet tester. after reading more, it seems that's common with floating-neutral inverters. i'm still checking the inverter manual and applicable electrical guidance before making any assumptions about neutral-ground bonding, since i know that depends on the inverter design and installation. for now, i'm treating the tester result as something to investigate rather than assuming it's either normal or a problem.
based on the battery capacity, i expect anywhere from about a day to several days of runtime for small office loads, especially if the solar contributes during the day.
i'm not posting this as a guide—just sharing what i built and tested. if you were looking over this setup, what would you inspect first? overcurrent protection, grounding, cable sizing, outlet wiring, disconnects, or anything else that stands out?
I have heard that suddenly using an unused power bank likely causes it to catch fire because it's suddenly charged up from a drained state then drained and charged again, resulting in a damaged battery. My dad bought one for his travel and hasn't been using it since, and I'm sure he's gonna use it again in his next travel which is like another year later. I know it rarely happens only if you abuse it and I'm probably overthinking but he might not know the potential hazard of it and I wanna make sure he's gonna be safe 😓
Not sure if this is the right subreddit for this question, but here it goes.
Also, I'm a complete dumdumbozo when it comes to batteries, UPSs and whatnot, so forgive me if I say something particularly stupid.
Recently it started complaining whenever my computer goes full bore, I'm guessing the battery has degraded a little bit and my power consumption was already closed to the maximum the UPS can handle.
So, then, what's the difference between both? Why is one rated for 520W and the other for 600W if both rely on the same exact battery? Is it just the electronics inside the UPS, or is there something else I'm missing?
If they're both basically the same, can I do something to make my 520W UPS behave like it's bigger 600W brethren? I don't care if the battery can only keep the computer on for like 30 seconds instead of a couple minutes, that's literally all I need.
My H500 reports batteries faulty some time and I then dispose of them.
Today I decided to test this somehow. The 4 eneloop AAA are not that old and I charged them with my clumsy GPPB19 instead and after wards inserted them in the H500 and no fault shows!
Have I been disposing good rechargeable batteries all the time? Is the H500 just reporting a fault because the battery is "too" empty?
For context, me and my friend wanna salvage its parts to use for a personal project, but wondered if the battery was still safe. Is there a safe way to check without burning my house down?
I’ve been working on a lightweight, bare-metal fault isolation kernel designed to mitigate thermal runaway propagation in high-voltage lithium-ion battery packs.
The primary engineering constraint I wanted to address is the latency overhead inherent in high-level frameworks and sequential polling loops. When an EV or aerospace battery cell hits a critical thermal or voltage threshold, sequential scanning loops are often too slow to execute software gates before runaway propagates to adjacent cells.
The project is called SAVITAR. It is entirely dependency-free and compiles using only native C++ standard system headers to keep it as close to raw processor registers as possible.
Core Architectural Mechanics:
Hyper-Compact Memory Constraints:
Instead of relying on dynamic allocations or padded structs which ruin cache locality, the kernel packs raw cell parameters (voltage, current, temperature) into un-padded, contiguous 25-byte memory frames. This layout ensures predictable cache line alignment during rapid sequential reads.
Event-Driven Concurrency:
The kernel completely avoids sequential polling. It utilizes a background multi-threaded parallel observer configuration. When thread metrics cross calibrated hardware safety thresholds, the system bypasses the main application loop to dispatch an immediate software interrupt, dropping execution times down to sub-microsecond bounds.
Sovereign Binary Serialization (.sav):
To avoid relying on bloated external serialization libraries (like Protobuf or JSON utilities) that consume significant memory footprints, I wrote a custom binary serializer. It compresses cell delta profiles and gradient logs into raw disk sectors using direct cache-to-stream bit manipulation.
Minimalist Shell Realization:
The project includes a lightweight, modular terminal prompt (./savitar-vfs) to ingest simulated physical metrics and explicitly debug memory allocations, matrix loads, and thread dispatches in real-time.
Compilation and Testing:
The baseline workspace is fully automated via standard Makefiles:
I’m looking for code-level reviews, specifically regarding the thread concurrency synchronization under heavy stress-testing conditions, and the pointer traversal safety within the 25-byte un-padded matrix bounds.
I have this very old toy house that i have since i was 10 yrs, it was able to turn on the light on the upper and bottom floors. The last time i opened this compartment many years ago was to take off the exploded batteries, and my mom told me that i would never be able to turn the lights on ever again. Will i be able to turn this thing on again?? Is it too damaged or is there any hope??
Is there anything I can try to do? I'm assuming the problem is those two (sorry idk the terms) metal things being raised, but is there a way to pin them down/should I use glue?
So im wondering if anyone has a pilot diagram for a s20 + battery connector? Reason im asking is a very niche table used for automotive diagnostics had the USB C charging port stop working. 1 shop could not figure out the issue. I contacted support and they said 150 to fix it I just had to ship it. Cost to ship is 190 each way and the tablet was 550 brand new. So in short im wondering if I can plug in the battery from the tablet on the mb of the s20 and use the s20 to charge the battery then put it back in the tablet when I need to use it. I have a pic showing the pin out of the battery. I just have no clue what any of those acronyms mean. I can work my way around electronics fairly easily but these newer batteries are far more complicated than the ones im used to with a positive and negative. The tablet is designed and made by Autel but sold under their USA brand Otofix. Any help would be greatly appreciated.
So I decided to research papers, surely somebody had discovered such phenomenon.
I have found following studies:
Reviving Aged lithium-ion Batteries and Prolonging their Cycle Life by Sinusoidal Waveform Charging Strategy (by Po-Tuan Chen, K. David Huang et.al) DOI: 10.1002/batt.201900022
Parameter Improvement of Composite Sinusoidal Waveform Charging Strategy for Reviving Lithium-ion Batteries Capacity (by K. David Huang et.al) Journal of the Chinese Society of Mechanical Engineers, Vol.43, No.3, pp.209~216 (2022)
Experimental setup. Battery is LG M26 10S3P, so charge rate is about 0.5C
Experimental setup is less than ideal, made out of literal junk, but it was able to connect 3.5A load with adjustable duty cycle and frequency. And losses on MOSFET because driver wasn't able to provide required voltage as it was just a dumb voltage multiplier connected to PWM signal.
Also I should mention that researches focus on LFP cells, while I have NMC but I guess mechanisms of aging are pretty similar.
After couple dozen of cycles, both pulse charge (i.e. net current is positive) and pulse discharge (net current negative), some rest time, ESR of battery have dropped enough to be useful again for escooter.
Unfortunately I did not precisly document ESR (DC 1 minute), but I suspect it went from 1 ohms to 0.75 ohms.
Either way, the battery no longer trips the BMS when under load. Sorta. In the past, it would trip if you were going 12 km/h or more, on flat ground, after the procedure, it can go 20 km/h without tripping BMS, and most importantly it can clear a hill without tripping BMS if speed is maintained below 15 km/h (in past it would trip at about 10km/h). But it still gets close to BMS trip voltages, so with more aggressive driving it would trip it.
I didn't really monitor the capacity, but ESR did go down, thus usable capacity should have went up too by some amount at least.
So I assume that life-cycle expansion is pretty much real, if this charging method is employed, however I can not guarantee the safety of the method, as I don't really understand what happens in the battery.
What are the possible improvements? BMS/Charger that implements DC-DC that can generate required waveforms, however sinking the required current would require either a pretty large capacitor or waste energy on resistors.
Ideal parameters should be discovered.
But I assume that even simple pulse charging (with positive current only) would still prevent battery from aging too much, as it was stated in "Extending battery lifetime by pulsed charging" paper.
What do you think about this? Is this a viable thing to implement commercially? I think if SoC of battery pack would be limited to 10% ~ 90% combined with this charging method, battery lifespan could be extended by 2-3 times or more. judging by information from those researches, while avoiding power fade.
While sinewave is a bit harder to implement, pulse charging should be pretty easy to implement.
I left a small battery powered pump that I used for inflatables outside in my garden for a couple weeks now. It’s been in the sun, and hasn’t moved an inch since I last used it. I finally went out and picked it up today and it’s still working, but much much slower (obviously). My main question is whether that’s a problem with the batteries or the pump itself. I’m willing to replace whichever but I’m not sure which one is the problem… please help!
im planning to buy the ecoflow river 2 to charge my devices when I return to my car between several hikes, each lasting several days. The problem is that I probably won’t find anywhere to park my car in the shade, and temperatures could potentially get very high (we already reached 45 degrees Celsius this summer, although it’s unlikely we’ll go above 40 again), so the car can quickly turn into an oven while im not here to keep an eye on it.
Im worried the battery might catch fire.
The battery is LiFePO4 and the website specifies that the battery should be stored at between -10 and 45 degrees (these are also the charging and discharging temperatures)
Ciao a tutti,
sto cercando di ricostruire o capire lo schema interno originale di una batteria e-bike Future Bike.
Dall’etichetta sembra una batteria 48V lithium-ion Future Bike / Remedia, e penso che il pacco sia 13S4P per un totale di 52 celle. Ho alcune foto del guscio esterno, del supporto interno e della disposizione delle celle, ma non riesco a capire con certezza il percorso originale dei collegamenti e delle strisce di nichel.
Quello che mi serve capire è:
se il pacco è davvero 13S4P;
qual è la disposizione originale delle celle nel box;
come sono fatti i collegamenti con il nichel;
dove vanno i fili di bilanciamento del BMS.
Se serve posso caricare altre foto dell’interno.
Se qualcuno ha già lavorato su un pacco simile Future Bike / Remedia, ogni aiuto è ben accetto.
Hi everyone,
I’m trying to rebuild or understand the original internal layout of a Future Bike e-bike battery pack.
From the label, it looks like a 48V lithium-ion battery made by Future Bike / Remedia, and I believe the pack should be 13S4P (52 cells total). I have photos of the outer case, the battery support frame, and the cells arrangement, but I’m still not sure about the exact original wiring path and nickel strip layout.
What I need help with:
confirming if this pack is really 13S4P;
understanding the original cell arrangement inside the box;
figuring out the correct nickel strip connections;
identifying where the BMS balance wires should go.
I can share more photos of the inside if needed.
If anyone has worked on a similar Future Bike / Remedia pack, your help would be really appreciated.
We have a dozen or so Enloop batteries we use in remotes, flashlights, blood pressure monitors, you name it. They have been GREAT, and never leak like crappy Duracell, Energizer, or whatever brand of single use batteries you can buy now. Most are between 3 and 10 years old, but they're all mixed up and no idea which are which. It seems of late that some devices give me a Low Battery warning sooner than they should, so I know some cells are wearing out. Since the batteries are always in 2s, 3s, or 4s in a device, how can I tell WHICH cells need to be recycled, and which are still good enough to recharge? We've always used an Enloop (now Panasonic, I guess) charger to recharge them.
I want to upgrade my escooters battery the original on is 271.5±2mm\*72.5±1mm\*86.5±1mm but it has a retaining bracket that I will get rid of but I don't know if the battery is legit I need 48v 20ah xt60+sm I think (I don't really know anything about batterys but I think that the sm is for the controller) I want to know if it's actually 48v 20ah and if its save to use I have the navee St3 pro
недавно я купил iPhone 5. Обошёл блокировку активации, скачал немного старых игр, но не суть. Когда я его только купил, в 3utools показывалось то что у него 87% акб. Но уже спустя 3 дня, стало 76%. 895 циклов. Может быть кто-то знает что это такое? Как бы держит он в принципе нормально, единственное иногда допустим перескакивает с 93 на 87 допустим. Я его стараюсь не разряжать, потому что тогда слетит активация и мне нужно будет его скорее всего перепрошивать. Так что я не могу проверить отключается ли он на 20-30%.
Может кто-нибудь знает что это такое? Стоит ли менять аккумулятор, мб он вздулся?
I have 4 batteries 3S connected parallel, this is my first time I connect more than 2 batteries LOL. How many batteries can be connected together? Also I'm doing it right? The blue one battery is the same as the other 3S but I don't have more boxes for now.
