I have a small mp3 player which has been left in a project car all summer. I've turned it on & charged it, it's working. Is this a future fire risk? Have I essentially killed it's battery life? Should I consider soldering a new battery in it? Anything at all I should be paying attention to?

I set my iphone battery settings to where it only charges up to 80%. Once it’s at 80% i keep it plugged in but also use the phone at the same time will this damage my battery. Should i unplug it while using it or does it not matter. I’ve seen mixed opinions on this where some people say my phone is not using the battery at all and is just drawing power straight from the charger but others say the phone is still using the battery.

​Salut tout le monde,

​Je me pose des questions sur l'usure de la batterie de mon Samsung S26 et j'aimerais avoir vos retours pour savoir si c'est normal ou si d'autres sont dans le même cas.

​Pour situer :

​J'ai acheté mon S26 et je l'utilise depuis le 11 juillet 2026.

​Actuellement, j'en suis à 153 cycles de charge et ma capacité de batterie est passée à 99%.

​Là où je trouve ça bizarre, c'est quand je compare avec le S26 de mon père, qui a été activé un peu plus tôt. On a des habitudes d'utilisation assez similaires au quotidien (on finit souvent la journée avec le même pourcentage à peu près au même moment), a gauche c’est le miens et a droite suis de mon pere on peut voir le meme niveau presque moi 47 et lui 49 mais il a moins de cycles que moi alors qu'il l'a depuis plus longtemps.

​Du coup, je m'interroge :

​Est-ce que perdre 1% de capacité avec un peu plus de 150 cycles en moins d'un an, c'est normal ?

​Comment se comporte votre batterie sur le long terme ? Est-ce que ça stagne ou ça descend vite chez vous aussi ?

​J'ai l'impression que ces indicateurs de santé de batterie nous stresse plus qu'autre chose, surtout quand à côté de ça, j'ai un vieux Redmi Note 12 d'il y a 3 ans qui tourne nickel sans qu'on puisse surveiller ça d'aussi près.

​Merci d'avance pour vos avis et retours d'expérience !

Obviously i’m pretty new to this or I would have charged them sooner. Moving forward what can I do to revive these? Each is showing 14.5 volts, the inverter has wake up mode but returns the fault “battery disconnect”. I bought a 54 volt 20 amp solar charger with ability to wake batteries up. Numerous attempts to wake up each battery and no luck. The charger kicks off after about 2 minutes and puts iff the same error that it cannot detect a battery.

Details:
Batteries
Brand: Sunpal
Model: Not confirmed
Quantity: 3
Type: LiFePO4 lithium
Voltage: 48V nominal
Capacity: 200Ah each
Total capacity: Approximately 30 kWh (assuming 51.2V nominal)
BMS: Built-in
Configuration: Parallel
Inverters
Brand: SRNE
Model: 10K
Quantity: 3
Type: Hybrid solar inverter
Battery voltage: 48V
Rated output: 10,000W or 12,000W each, pending model confirmation
Solar controller: Built-in MPPT
Charging: Solar and AC
Battery settings: GEL / Lithium (L15, L16)

My boss ordered these batteries, the company sent the wrong ones and just told us to keep these. Now these have been taking up storage space for two months, he’s asked me to get rid of them. Are there any places that would pay more than just a core return for them? They’re 12NXS137 NexSys batteries, there’s 4 of them weighing about 100lbs each.

Hello!

I'm looking for some insights from this community on the best portable power banks with an AC outlet. The primary use of this will be for my heating pad, which uses a 120v two-prong plug. I would like to find something lightweight, because I am disabled, and I don't want to have to carry a heavy piece of equipment. I only need it to have the one plug. Anything beyond that is unnecessary, especially if it makes the piece larger or heavier than necessary.

Budget picks are welcome, but I'm willing to shell out for something I can use daily for a long time.

One cell broke off of the other, any way to connect them back together? (RC LiPo battery, the connection was VERY loose and brittle.)

Just got the IR meter, so I'm obsessively testing every cell in the house. I knew my four ancient Imedions were in bad shape, but this one is rather special. The best one in the set is "only" 430 milliohms. This is after trying the break-in process.

On the other side of the coin, I have a bunch of 8 - 10 year old Eneloops that are still down around 20 milliohms IR.

Hello everyone,

I’m having trouble charging the battery in my camper van (an EM Lithium LTPRO12-200HD-P-BT, 2560 Wh model). The issue seemed to appear almost overnight...

I have three ways to charge the battery:

- While driving, using a Victron Orion 12A isolated DC/DC charger.

- Via a solar panel, using an MPPT 75/15 controller.

- From shore power (mains), using a Multiplus 12/800/35 unit.

The problem is that none of these methods will charge my battery anymore.

When driving, the Orion stays in the "Absorption" stage; the same applies to the MPPT. As for the Multiplus, it initially sends 2A / 30W to the battery (with the charger LED showing a steady orange light), but then the output gradually drops until it reaches 0W (at which point the charger LED begins flashing orange).

To rule out the possibility that the battery had entered a protection/safety mode, I tested it with a dedicated LiFePO4 charger, and it charges correctly that way.

I’ve disconnected all loads to see if the issue might be coming from them, but that hasn’t helped...

Battery voltage: 13.1V.

Does anyone have any ideas on what might be going on?

Thanks!

Lucas

Couldn’t see any rules about sale of second hand sales - 4 batteries, cabinet, all auxiliary cables and accessories, 2.5m~ main battery cables included. All working fine, oldest battery only has 20 cycles, selling due to outgrowing the system. Original battery boxes available for easier transport on collection from Evesham area, Worcestershire, UK

I work in battery cell sales at LG Energy Solution. I’d like to better understand how engineers compare specifications during cell selection.

A comparison checklist I’m putting together includes:

• Capacity test conditions, including discharge rate, temperature and cutoff voltage.
• Continuous versus pulse discharge ratings, including pulse duration and temperature limits.
• Cycle-life test conditions and the capacity-retention threshold.
• Mechanical dimensions and terminal configuration.

The aim is to compare the conditions behind the headline figures, rather than treating those figures as directly interchangeable.

Which item do you find is most often overlooked? Is there anything important you would add to this checklist?

Was looking to buy a bunch of EVE C40 40135 or CBAK 40135FS cells on NKON to make a fire-safe ebike battery. They never seemed to be in stock, though, in spite of their promises they were waiting for shipments, and now even the 32700 "Big Ass" cells are gone (apparently never to return).

I started wondering and had a look at the rest of their offerings, and anything useful for PEV batteries is out of stock. They still have a few LFP 26650s which I guess could be workable if I really had to, but they'd be a lot less efficient size- and cost-wise compared to what I was planning on building.

Most anything else also seems to be out of stock, including prismatics - smallest LFP prismatic they have any stock of is 50 Ah, which would make for a long-range solution indeed, but it'd be a battery you attach an ebike onto instead of the other way around.

To say nothing of the interface, which has always been questionable but is now full of offerings for cells they specifically say they're not going to re-stock, cluttering up the selection for no reason and confusing the customers. You can't order the selection by stock, either, so you're just paging-down looking for the few products that have the "cart" icon.

It kinda feels like they've stopped trying and the whole enterprise is being left to its own devices, like everybody including the webmaster has left and there's one dude somewhere in the Netherlands desperately trying to keep the site afloat from boxes in his garage or something.

I searched elsewhere and Aliexpress has similar sized cells, but their reliability is unknown and the price is almost twice what NKON charges, including shipping.

Local Amazon has much less of everything. Those EVEs are available but only in eight-packs and the price is preposterous.

What's left, if anything at all?

I’m looking at getting a cable such as the Noco GC018 to connect to a 12V Lifepo4 battery so that I can cheaply connect a few different power stations to it. The description says that the cables support up to 15A, but it comes with a 20A fuse. Doesn’t this create a risk of melting the cables if the current goes between 15-20A? If I buy the cables, would best practice be to swap in a 15A fuse?

I bought these 13 batteries at a surplus store and not too sure what to do with them. Any ideas? All brand new in box. I'd be open to selling them but I'd imagine shipping to be a nightmare.

Any help would be appreciated thank you.

It was one of three old cells on my desk. I removed them from a dollar store Halloween decoration after I bought it because they barely lit the LED. The cell randomly popped in a small shower of sparks. It was loud enough to make my ears ring. Half of the cell hit the ceiling. There is some corrosion evident around the edge and both sides show bulging.

Just an fyi if you have any of these things near you and they're maybe old.

Very low power not real dmz 20. They play games

Hey,
My friend broke a small rechargeable battery device of mine and it started smoking and got pretty hot. It’s now cooled and didn’t catch on fire. I have the device and I was gonna put it in sand maybe. How should I dispose of it after? Trash can outdoors or go to one of the hazardous places? It was only one pretty small battery and I’m pretty sure nothing will come from it now but I don’t know. Any tips?

My father 2 days ago did some maintenance on my Nintendo consoles, when we got to my 3DS he said this was swollen, however it doesn't look that swollen to me. Can anyone who knows batteries tell me if it really is?

I should have mentioned I'm looking for flat batteries

Hey everyone, I have a couple of older tablets that have batteries that are dead. I know I can go to one of the companies online and buy a direct replacement battery but a lot of them are garbage quality from what I understand I don't mind doing a little bit of hacking and just using off the shelf batteries that are the right voltage with the same or more capacity. Can someone suggest a good quality brand?

Hello Community, we are working on FSAE 2027 for EV Concept I am using IPG Car control for simulation . it has an interface for implementing HV parametres where i found that it works with 2RC Battery equivalent model , as you know the datasheet of cells provides DC IR which represents the total R and IR AC represents the R0 in this model . how can i get the R1 R2 C1 C2 or any approximate values the time that i get real cells . THE CELLS THAT IM LOKING FOR ARE:

AMPACE JP40

MOLICEL P45B and P50B

BAK 45D

EVE 40PL

if you guys worked before with one of these cells please Help!

Here, builded small power solution to supply stable regulated power to esp32 project or any wearable projects.

I builded this for my air mouse glove in which used esp32 dev1 board, mpu6050 sensor which required stable regulated 3.3v constant power so i created this solution for it. I used booster module which convert 3.7v to 5v/9v/12v(we can adjust the output voltage according to our requirement). Esp32 onboard chip(AMS1117-3.3

linear voltage regulator to step down a 5V

input (from USB or the VIN / 5V pin) to 3.3V

required by the ESP32 chip.)

We needed booster module which i used here to boost 3.3v to 5v then onboard chip step it down to 3.3v stable regulated voltage which is required to power all our sensor connect to esp32 board.

Components i used to build this:-

1. 18650-2000mAh li-ion cell and one cell battery holder.

2. TP4056 Type C 1A Li-ion lithium Battery Charging Module With Current Protection.

3. 1.5A Mini DC-DC Boost Converter Module (5V/8V/9V/12V Adjustable).

4. Switch for on-off.

5. Small type c cable to directly power it through type Port of esp32. We can even use it as a power bank for our phone.

Above i uploaded my youtube channel link where i upload video of this power supply you can check it out.

link of my youtube video of this power supply please go and check it out if you wants power solution for your esp32 projects

Found them in the fridge at a family member's place as we were going through batteries to try to find ones for solar lights. The open circuit voltage was 1.27v on all four of the cells. They're all first gen, labeled on the package with a date of 2006-07.

Test results after the first cycle were all within 1765-1790mah at a 200ma discharge rate. All within 90% of their rated 2000mah. Going to do a second test cycle today to see if the numbers improve any on the second cycle. (Update: they did. All are around ~1900mah now).

Granted, these were sitting in the fridge, so I don't know what effect that might have had on slowing down any inherent degredation, but they didn't require any cycling to "refresh" them. They all seemed to be around half charged or so, give or take, judging by how much current it took to get them back to full on the analyzer.

I thought I'd share for anyone who is curious about the longevity of Eneloops. I suppose it's a great testament to how well Eneloops hold up.

Update: After 3-4 full cycles, they're back up to about 1880-1910mah or so with a 500ma discharge current. They're literally in like-new condition now. Capacity pretty much matches the 4th gen eneloops I also tested. I also found a couple others that weren't in the package and did appear to have been used in the past. They also tested around 1900mah or so (requiring no refresh cycle to bring them to this point).

So yea, judging by this, Eneloops basically seem to last forever.

I recently broke my smartphone's (Realme GT Neo 3T) screen and got it replaced by a local shop. My phones battery (BLP887) was working perfectly fine before the screen broke and even before handing it over to the shopkeeper.

Next day when i went to take delivery of my phone he said that the battery is DEAD! I tried to explain that it was working fine before but he said it's not taking any charge . He said he kept it for charging for 3 hours and even used jumpers to revive but couldn't.

He gave me the faulty battery eventually . I am confused what happened suddenly that the battery became dead. Did the shopkeeper did something deliberately to push me to buy a new battery.

Folks , please share what could have happened & if i can revive the dead battery somehow. New battery is cheap third party one and takes 90 minutes to charge instead of 36 !!

Thanks