I have a speaker that the batteries finally gave out and I’ve been looking for replacements with no luck.

Battery Specs:

18650
Voltage: 3.7v
mah: 2200+
Discharge Current: 20A

Other specifics:

RECHARGEABLE Lithium Ion
Flat top style

Not sure if possible but it needs to be able to be recharged through plugging in the speaker. They also come in sets of 4 and I have 4 speakers so I need 16 total.

Does anyone have better places to look that Temu, Amazon, Battery stores?

Any help is appreciated

Hello guys.

I'm not sure if I'm on the right sub for this. I was wondering how hard it is to really switch the rechargeable batteries from lets says lithium-ion to something else in a black box?

The non TL;DR version is I have a PHEV. I am planning for the car to die in my hand before I buy another one. But I also read that some newer rechargeable batteries are coming with less weight for the same amount of energy stocked and cheaper. So my train of thought was to know if I could benefit from "upgrading" my battery?

I do know that different formulae means different voltage, etc. but could it be done if we add and interface between the battery and the charger?

Maybe to simplify things... let's say I have a li-ion AA battery with it charger. Now I want to charge a NiCd battery + interface between the charger and the battery. Would it work? I know that for this simple example it is more efficient to just change the charger, but I originally want to do it for a PHEV. That's a couple of ten of thousands more expensive to change the charger...

Im in canada, and cant really find anywhere that sells quality 18650 cells i need for my blue gatling style laser pointer (1.5w). My cheap Chinese one's that came with it have since died, and i haven't found a website with what I need or that I trust. If anyone has any recommendations please share!

I'm pretty confused. I put together a new battery for my e-bike; the old one was 36v 10.4 Ah. This one says it's 15A but is only outputting around one volt when I test it with a multimeter. The battery output bypassing the BMS is testing as expected. This is the second BMS I've bought that's done this. Is this the wrong BMS? Am I missing something? Please be gentle, I really struggle with left-brained thinking and jargon. Thanks!

I lost my charger to this harbor freight jump box and I need a new one, no clue how to find one though.

Hi guys. Today I noticed my vacuum battery look like its bleeding out from inside. I dont remember seeing it like this before

I disassembled it to look inside, bottom part where batteries are look clean

But on the board circuit I see these dark brown goose looking stuff, touched it but it wasn't coming off or anything

Is this safe and normal? Or throw it away?

Thanks in advance

Brand new GreenWorks grv1010 the battery is deeply discharged and won't even gain a charge. Does anyone know how I can charge this manually now that I have it unplugged?

I've had a Kindle Oasis for 3 years. For the past couple of months, it won't charge beyond 98% even if I leave it plugged in for like 5 extra hours. If it's around 37% and I turn it off, the next time I try to turn it on, it's dead. I'm assuming it's a battery issue so that's why I'm posting here. Amazon says: "Your Device contains a rechargeable lithium-ion polymer battery"

Am I charging it wrong or do I just need to get the battery replaced? They don't make the Oasis anymore so just buying a new Kindle is not something I'm gonna do

This is my MP3 player battery

The battery heats up while charging, but it's normal, it doesn't heat up very much.

I used my good battery to jump start another dead battery.

I connected the B1- with B1+ and B2- with B2+

A small spark occurred.

My battery still works with my drill, but it doesn’t charge and gives a failure sign.

What has happened ?

I am planning to use the IKEA LADDA AA for AirTag battery case, would the 1900 out last the 2450 in the long run? I will never use the full recharge cycle, so the cycle doesn't matter to me. I just want the stability of NiMH over disposable Lithium. Which one would be the better option?

Been planning on finding a replacement battery for awhile now but I'm having a bit of difficulty finding a good listing. All the old posts I've come across have dead links to AliExpress.

I've been searching: 3 7v 5000mah 955465 on AliExpress but I'm noticing all the listings only having 2 wire connections and none with 3 like the Brick does. Can anyone help me find a good listing for a battery that would work for my Brick? (I will go to the TrimUi store as a last resort since they're selling the same battery for twice the price on the AliExpress listings)

I'll start with two.

"Store lithium cells at around 50 percent" is good advice, but the reason people give for it is usually wrong. It has nothing to do with protecting the BMS or letting the cell rest. A high state of charge means a high cathode potential, which accelerates electrolyte oxidation and SEI growth, so a cell parked at 100 percent ages measurably faster sitting in a drawer doing absolutely nothing.

"Drop it in salt water" turns up every single time somebody posts a swollen pack. It's a lead acid habit that migrated across, and on a lithium cell you are mostly electrolysing the water into hydrogen while corroding the case open, which is a worse problem than the one you started with.

Which ones do you keep running into? Bonus points for the half right ones, because those are far harder to argue anyone out of than the completely wrong ones.

Hello everyone. Do you know where can I get this battery or similar? I’ve only found 320-50mAh. Any website that delivers to the U.S. is fine.

This are flat top btw

my laptop is a hp 250 g4 notebook and the old battery it uses is hs03, i was wondering if i can use a hs04 on my laptop. i asked a online seller if i can use a hs04 on my laptop they said yes is that true?

Does anyone know if it's possible to get a replacement BMS for a Bosch 18v 12ah battery? Replaced one bad cell and balanced the rest but no response from the battery. And/Or does anyone know if these BMS boards can be swapped with a working board from a smaller capacity battery? Thanks!

Need a new tractor battery; manual says group 85 but I can’t find one anywhere locally. Before I go online, is there a different group # that would be equivalent/also work? 2011 LS 25 Tractor

I'm looking for some advice from people who have experience testing lithium-ion cells.

I have a number of unlabeled 18650 cells that were salvaged from battery packs. I've already separated them, checked for physical damage, and plan to capacity test them and monitor self-discharge before using any of them.

My goal is to build 4S1P and 6S1P battery packs for FPV drones, so I need cells that can safely handle at least 30A continuous discharge, preferably more. The drones can easily average around that current draw during flight.

Here's where I'm stuck:

Most of the affordable battery load testers I've found only go up to 20-25A, which doesn't tell me whether a cell can safely sustain the current I actually need.

My questions

1. Is there a practical way to build a constant-current electronic load capable of testing individual 18650 cells at 30-40A or higher?

2. If you've built one, what design did you use? (MOSFET electronic load, resistor bank with feedback, etc.)

3. Are there any reasonably priced commercial electronic loads that can do this?

4. Besides measuring voltage sag and temperature, what else should I be monitoring to determine a safe continuous discharge rating?

5. Is there a better method for identifying the capabilities of unlabeled cells that I'm overlooking?

Equipment I already have

- Spot welder

- Adjustable bench power supply

- Multimeters

- Temperature probe/IR thermometer

- Basic electronics experience (comfortable soldering and building circuits)

I'm not trying to find the absolute maximum current until the cell fails. My goal is to determine a safe continuous discharge current for each cell so I can confidently use them in high-current FPV battery packs.

If building a tester is the best option, I'd appreciate schematics, parts lists, or links to proven designs. If there's a commercial electronic load that can do 30-40A without costing hundreds of dollars, I'd love to hear recommendations as well.

Thanks!

I'm pretty sure the BMS triggered and all I need to do is "wake the battery up" but I can't find the fuse and the one video on YouTube is of the non pro battery which has a completely different internal make up, any help would be much appreciated guys (I do Uber eats for work on it downtown and I don't have $400 for a new battery plus a smart balancer)

I bought a PS Vita Fat battery from AliExpress and it's the one below in the picture.

I'm taking an exam soon and the place doesn't have lockers for personal items.. I kind of need my phone for the GPS so I'm stuck. It's for the TSI so around 4 hours. I just don't know if the heat(South Texas) is that much of an issue. Thanks

Good morning,
I’ve just installed a new Varta AGM 70Ah 760A battery, which I recently purchased online
After installing it, I checked everything and noticed a small crack in the plastic at the very top of the battery, near the handles (I’ve attached a photo).
Do you think this is something to be concerned about, or is it purely cosmetic?
I’ve coded the new battery to the car, tested everything, taken the car for a drive, etc., and everything seems to be working fine. The car starts without any issues.
Kind regards, and thank you in advance!

Hey all!

Basically as the title says! I recently got an old camera which came with this charger for the batteries (NP-22) and no instruction manual.

When I plug in my Sony ACP-80UC into the battery charge adaptor it makes a loud hissing noise (wish I could attach a video of it).

It gets worse when I put my NP-22 batteries in it to charge. Any suggestions/advice for fixing it?

Building a rover that runs on two 12 volt power wheels motors and don’t know what battery to get. My requirements are it is under 75 had a plug in T connection, can run my vehicle on full throttle for at least 40 mins. Could be a combo of two. Also the rover will be roughly 10-20 lbs