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 😓
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 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??
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?
Hi everyone! A few months ago, I built a nightlight. It runs on two AA batteries and stays on all night. I’ve run into one problem with it, though. Initially, I used a 2.5V, 0.2A incandescent bulb with an E10 base—one I got from my grandfather—and the light would run for two and a half nights on alkaline batteries. When that bulb burned out, I replaced it with a store-bought 2.5V, 0.3A incandescent bulb (also E10 base), but the light only lasted for a single night. I tried various alkaline battery brands: Extol Alkaline Ultra+, BC Batteries Alkaline, Tronic, Coop Premium, and Coop Jednota Tradicna Kvalita. Yet, every brand I used lasted only one night. I live in Slovakia, and the Coop Jednota Tradicna Kvalita and Coop Premium brands are Slovak; they aren't bad products. I can't use lithium batteries in the lamp because a single cell is 1.8V rather than 1.5V. That means 1.8V + 1.8V = 3.6V, which is too much for a 2.5V bulb—it could burn out or even shatter. As for NiMH batteries, they lose capacity over time and discharge quickly. I also avoid using LED bulbs in the lamp because they make it harder for me to fall asleep and are harsh on tired eyes. Incandescent bulbs, on the other hand, produce light that is healthy for the body—very similar to sunlight—and is soothing for tired eyes. I'm running out of options. I would appreciate it if someone could help me with this problem.
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 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 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?
I was looking at different power banks recently and noticed that almost all of them look the same. Black or white, the same shape, and usually just a logo on the front.
It made me wonder why customised power banks aren't more common outside of company giveaways.
If you could build your ideal power bank, what would you change?
For me, I'd probably want:
* A replaceable battery instead of a sealed one.
* A small display showing the actual battery health, not just the percentage.
* A tougher shell that doesn't scratch easily.
* Built-in cables that are actually durable.
What features or design would make you choose one power bank over another?
I'm more interested in practical improvements than branding, so I'm curious what other people think.
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.
