Reddit, I've got a 12v sealed Lead Acid battery around 10 years old, sat on the shelf unused until today where it's down to 10.8 volts. I have battery tenders in the house, the kind designed to top off and keep charged cars and motorcycles in storage (Battery Tender is the actual brand, 1.2 or 1.5 amps, small clamps?). Is it safe to connect it up to this battery on the shelf and bring it back up? I will never, ever use this for an automobile, just to connect a small inverter to in the event of an emergency, I realize this is lead acid, don't drain below 50%, this is more "I have this thing, can I use it? Should I attempt a battery-tender recharge or leave it alone? I just need to know if it's safe to try a battery-tender recharge or if I'm better off just turning in the core. Thanks!

Have a friend who wants me to invest $100k in a battery shop in Kansas City area. Mostly car and truck batteries, new and used. Buying out someone else’s shop but changing LLC and names. My main concern is investing a lot of time and money into a dying industry. Maybe I’m misguided but the way EVs and hybrids are going, how much longer will a small battery shop be profitable? At some point manufacturers are going to own the battery industry and squeeze out the small shops even if we moved into replacing EV batteries

Hey all, I'm currently designing a parallel charger for all my cells, and any future ones I may acquire. I want some sort of holder similar to the ones that the lii-500 uses, I can't seem to find anything like it for sale. I want to be able to fit 18650, 20700, 21700, 26650, ect.. all in the same holder

I'm trying to run an esp32-s3 USB c off of a single 18650 battery. My circuit is one of these charger modules

EC Buying 5Pcs Type-C USB 5V 2A Boost Converter 2A 5V Charge Discharge Power Module Lithium Battery Boost Charging Power Module https://a.co/d/4Cbgrwu

That have the 2 battery pins going to the positive and negative of a 18650 battery holder and the 2 output pins going to the vin pin on the esp32 and ground to a gnd pin.

Whenever I press the button on the charger module or connect power to Vin, The esp32 and charger module flicker on for a split second, then don't stop working.

Now I've used a multimeter to check some voltages. The output of the fully charged battery is 4.1, which is expected. I'm not connecting anything to the battery directly, I just wanted to see if the battery was charged properly and had a good connection. The output of the charger module was rated at 5v constant, but the multimeter started around 4.6v and as it became fully charged, the output was around 5.1v which I think is also expected. It looks like all my wiring is correct and nothing is faulty, but I can't get my esp32 to power up. When the USB c is connected to the charger module I can connect the power and ground to the vin and gnd, but it gets extremely hot. That isn't a major issue, but I'm "supposed" to be able to power a device while the battery is charging, but my main goal is just to use the battery without the USB connected. The esp32 works fine when directly power from the USB port too

What could the issue be? The Vin always mean 5v or should I be trying to power the esp32 using the 3.3v with some kind of converter instead? Do I need a capacitor or resistor anywhere on this circuit? I tried a few esp32s and the result was the same, so it has to be my wiring or components being the problem. Also the USB chargers I'm using are pretty high amperage, more than the 2a the charger module output is rated for, but that doesn't seem to affect the charger module or battery, it never got hot. The esp32 did get hot when the USB c was connected to the charger module, so that may have something to do with it too.

https://preview.redd.it/gujs04gxv3yd1.jpg?width=3000&format=pjpg&auto=webp&s=968417de0a40236e42bcd4328056fb91615ec126

Hi everybody.

I live in a small town in a country where no one really speaks English. And there are really no Miatas around almost anywhere; I was very lucky to find mine.

It's a 2014 and the battery just died.

The dead battery has a label that says: 45Ah 300A.

The new battery that the shop wants to sell me says: 40Ah 360A.

The new battery is the right size to fit the Miata, but I'm not sure if having mismatching numbers like this is a problem.

Will this new battery work for my car?

I have wireless headphones that have their own dock for charging and contained 2 generic rechargable light-green Ni-MH AAA HR03 1.2 V 550 mAh batteries that got way too weak and lasted for very little when charged over the years so I bought replacement Panasonic eneloop batteries with the exact same specs but with 800 mAh and now when I put the headphones into the charging dock it doesn't charge no matter what (the LEDs don't light up, maybe I just have to drain them properly first, but the weak old ones do start charging like normal).

new vs old batteries

detail on the charging port and the place where batteries are stored

Hi can i charge my 12v 100ah lithium battery with a 20amp charger and have a second wire connected to the the battery lead to use a device while its changing?

Hello,

I’m new in designing PCB’s and looking to implement a rechargeable module on my board with a zinc air battery. Does anyone know where can I find documentations on that specifically? I found a Texas Instruments document on rechargeable module but only for other types of batteries.

Thanks

Hopefully this is right subreddit, if it isn't, let me know if there is a better sub to ask this.

Long story short, I work at a film equipment rental house, and we rent out all sorts of film/lighting/camera gear to customers. One of those items is batteries for cameras. We have about 2 dozen of one particular battery, an LP-E6 battery for Canon cameras (like these batteries).

We have purchased them over the years at different times, and they are not all Canon branded (some are Canon, some are Watson, some are generic/no name). Most of them are the same capacity (roughly 7.2 - 7.4V, 19.6Wh, 2650 mAh).

We've had issues lately with the batteries draining very quickly, even after fulling charging them up to 100%. Recently a customer rented three of the batteries for their Canon 5D camera to film some footage as a B-cam, but each battery died pretty quickly (one lasted 30 minutes, one lasted 15 minutes, and another lasted 5 minutes). We got the batteries back from the customer and put them on our dual LP-E6 battery charger (which has a small screen and says what percent each battery is charged to), and the screen told us that each battery still had plenty of charge/was not 100% dead (one battery immediately showed it was at like 60% charge, another battery said it was at 50% charge, and the last battery said it was at 70% charge).

I know Lithium Ion batteries like this degrade overtime and lose their overall capacity and die quicker and quicker, but is there some sort of test we can run on each battery to see what the "overall health" of each one is (and then determine whether or not we need to replace it)? We don't want to outright replace each one, as that can get expensive, but we at least want to replace some of the really bad ones that are on their last leg.

Is there some sort of semi-cheap battery tester device that measures discharge/overall capacity/etc of the battery that we can purchase? Or could we get enough info from using a multimeter? Simply charging them up to 100% and then putting them in a camera to run them down doesn't seem scientific/accurate enough, so I don't think that would give us a definitive and precise answer (plus it would take forever to do so).

Im talking about this one, not the other famous Air 8: https://isdtshop.com/de-de/products/a8-air

Is anyone using this charger?

Really, I have no clue what's wrong with this device, but I don't get it at all.

I just want to charge my NiMH IKEA LADDA. Nothing special.

But the APP is driving me crazy. I really don't understand what the charger is doing. All the values given seems arbitrary.

I'm not really shure if my batteries are charging or not.

Anyone experienced something like this?

For a while i have had a camera from 1984 with automatic film winding. It runs of AA batteries but every time the film winds its really slow as if the voltage is sagging under the load. Now i found some lithium AA batteries and there is no noticable problems with the winding anymore. I'm just wondering if "oldschool" AA batteries from the 80's were able to kick out more current, or am i just bruteforcing my way through an actual problem?

Everything is in the title : I want to have two 24V 500W motors, and i don't know if i should go lead or lithium

I'm looking for something not too expensive, and i can work my way around weight and volume issues

Edit : by not too expensive i meant _cheap_ like properly cheap, under 200 bucks

I have 4 batteries running in series-parallel at the same time and I want to add a 5th battery to get the most voltage to run an e-bike. It is a 2000w hub motor that can run 48 or 52 volts. I am upgrading from an old kit. The batteries are 18 volts 12 ah drill batteries (M18 Milwaukee) so right now running at 36v 24ah. is there a way to add the 5th battery to gain even more voltage? And will it work with the e-bike kit? Thanks in advance

I have an energizer charger with batteries all fresh, after a few hours I checked the batteries and they felt HEATED so i tested them out on my vr and they felt vr says they’re at 100% on the dot. Yet the charger claims its still charging, is there any way to fix this or any reason it’s happening

Hello All,

I built a soldering fan a while ago using an old 12V fan I had lying around and some alkaline batteries but I'm finally tired of replacing the batteries and am looking to upgrade it to rechargeable using some of my roomate's old vapes. I am very much still learning about batteries so please forgive me if this is a noobish question. I've struggled to find an answer that didn't leave me with more questions than I went in with.

I want this fan to run off a 3s configuration and be charged via USB-C. Do I need to get a 12V USB-C trigger board or can a BMS accept the standard 5V of a USB-C to charge the battery?

Thank you!

I'm hoping someone can point me in the right direction of where to read about this topic. I need a portable power station for events I do, I need to run at least 4 LED flood lights for 10 hour days (lowes website says these specific bulbs are 110v, 13w) plus i'd like to get some phone charges out of it. I impulse bought a DJI Power 1000 (1024wh), but i'm wondering if it's right on, overkill, or not enough. I figured its probably like 16hrs of runtime for the lights with the losses of stepping up to 110v. Right now, I use Ryobi 18v 4ah batteries with an AC adapter, I was getting about an hour per bulb. Im trying to use an online calculator to convert Wh to Ah to compare what I have to what I bought. The calculator requires Wh and Voltage, but is that the voltage of the internal batteries, or the 110v output? Additionally, It came with a free 12v "car outlet" type adapter, does take less of a hit converting whatever the battery voltage is to 12v rather than stepping up to 110v (if i were able to get 12 or 18v lights)?

Sorry about the mismash of questions, my head is spinning trying to research the batteries and figure out exactly what I needed!

this is the power station I bought, it was a flash sale for $500. It seemed like a decent mix of power vs portability. https://www.amazon.com/dp/B0CZ5RYBWW

I'm creating a dummy battery for a 360 camera (Rylo360) and trying to supply it power from an external source so it can record for much longer. The battery has 3 pins, the left one of "-", middle one is "T", and one on the right as "+." It uses 3.8V. When I try supplying power to the positive and negative terminals, the camera doesn't turn on, presumably because it doesn't detect a battery.

What do I need to connect to the "T" pin to such that it "tricks" the camera into thinking a battery is present, and allows me to record?

My kid got an old power wheels for her birthday and my father in law bought an adapter that would let me tool batteries run it. He wired it up and it ran fine. I didn't take the battery out right away and now it's been about a week. I finally take the battery out and it's totally dead so I go throw it on the charger and nothing happens. No lights saying it's charging or anything. I verify the charger works with other batteries so I figured maybe I'd let it be for a while and it'll show some life since I never drain them all the way like that.

Any idea why this power wheel would kill my battery and is there anything I can do to try and revive it?

6.5 year old battery. But only 28,000 miles on it. 450 CCA orignally 51R. I am trading in the car in the Spring 2025.

But the car is taking a few seconds to start in mornings now. May get worse as weather coldens. I am in Bay Area. Winter gets about 30 degrees at the worst.

Got battery tested, came to 372 CCA (450CCA orginal) and 12.49 volts. Mechanic said I could try just buying a charger and retest. But another said I should just buy a new battery.

What do you think? Seems the CCA is okay, could it make through the winter to Spring? But it is showing some struggle to start up and is quite old. So idk...?

To give background, I'm a computer repair shop. I do microsoldering repairs to apple logic boards and other complicated repairs - so I'm no noob to electronics. I often catch myself schooling customers on laptop chargers, telling them "a larger charger, as long as it's still a 19v model, doesn't matter if it's a billion amps, because the battery will only draw the amount of current necessary".

Recently, I decided I wanted to build my own solar charging rig for rechargeable batteries such as AA, AAA, 9V, etc... But what's the theory behind this? What's the fundamental knowledge? If I have, for example, 4x AA batteries to charge, given they are 1.5v units, what voltage do I want? How much is too much? What about current? Is it the same rule, that it could be a billion amps and still fine?

Where can I learn the fundamental principles of battery charging so that I might apply that knowledge to a wide variety of applications as I build my own off-grid contraptions(safely)? Such as, do I wire series, parallel, how many volts, amperage, etc?

I just a video where a guy fully discharged a Li-ion cell and took it apart with no issue and that prompted me this question.

Hello,

I am trying to set up a 16S battery to work with my solar inverter. I have a inverter that works with a bunch of different battery protocols, including Pylontech and others. The Daly BMS has the option for Pylontech RS485 output as well.

I am able to communicate with the DalyBMS via RS485 from my PC with the Daly program, but I don't see it communicating with the inverter. I see the inverter sending out information on the RS485 bus, but it doesn't appear the Daly BMS is replying. When I unplug the RS485 port from the BMS, I still see RS485 messages on the bus. When I plug the Daly BMS back in, I see the same messages with the same length, which means the Daly BMS is not adding any messages

Has anyone here gotten the BMS to work with an inverter? Am I doing something wrong?

Hi Guys, Am exploring on Battery Testing in which am more interested in Battery Emulators and BMS systems. I want to know if it's possible to perform Testing on the Daly BMS using a battery emulator like the ones from keysight and Hioki.

Hello everyone, i'm lost in a project, any guidance will be very supportive and helpful, thanks in advance.

I'm been scavenging these disposal vapes, here in my country all of them has this 13400 cells (3,7v 550mAh), to create a 10v battery pack for my vintage camcorder. I've been put 3 cells in series, to get 12v, and then a LM7810 regulator to limit the current to 10v. The thing i don't properly know yet is the BMS and USB charger i need for this project, because i'm afraid of burning my camcorder.

Thank you!

https://preview.redd.it/8ib8u0fdnpxd1.jpg?width=1600&format=pjpg&auto=webp&s=e122bef165c754c7aa76f1a00c23b340b3c2df21

SOLUTION - Found amperage 60A battery: https://dammesangtao.com/29337/cell-pin-21700-lishen-li-ion-37v-3000mah-20c-xa-60a.html

Batteries are purple lishen 21700 with this label: “ 03BCEA4JV1888 +A9CL0796760- “

For charging and telling the IR reading I use a XTAR vc2sl.

The batteries are brand new(or i hope they are), I got them inside a flashlight when I ordered it.

It had 2 batteries to be used in series.

When I went to charge them the first time the IR reading showed 15mOmh for the first one, 33mOmh for the second one. To me this seems like a problem since the batteries are supposed to be in series.

But when I remove the batteries and put them back. Then the IR reading changes.

Even one time it shot up to 100 so I could only charge at 0.5A. But then when I removed and put back it went back to 26mOmh.

Questions:

1. How can I tell the amperage on unprotected cells?

2.Why is my IR reading changing?