r/batteries

I bought this from second hand market and the battery is showing used on parts and service and manufacturing date looks like this

Gawdamnit.... And these were meant to be "industrial" for our use in hospital... FML

Contaminated the entire box as well.

Edit: I'm a doc. This thing was meant for an emergency laryngoscope. If you know what that is you can probably understand how pissed I was when I went for it.

I'm guessing there was an administration choice made here. And thanks everyone on suggesting lithiums.

Think this is good enough to make a case study.

Btw anyone got any hard data on lithium leaks vs alkaleaks?

I've been trying to find such a type of battery for a handheld device I'm working on. 1000 mAH is the minimum requirement. I really like the above mentioned battery as it's easily swappable, easy to install & low profile.

I can't seem to find them anywhere aside from Amazon, etc which is likely a clone. I don't require them in bulk yet but I do want to ensure availability doesn't become a issue if the sales become high.

From what I understand these batteries are certified, so I don't need to certify them myself.

My Xiaomi Mi 3i 20,000 mAh powerbank fell from shelf (height of about 2-3 metres) and its casing has opened up from the side like this. I tried pressing it in to close it but its not fixing.

Last year, it also fell like this and opened up the same way, but it closed upon pressing. This time its not closing.

I have a Ryobi 40v battery that stopped chaeging. I measured all the cells (10 cells) as shown in the picure.

Tried resetting but no good. Is this a sign of a bad PCB? Or a damaged component in the thermal management system?

Hopefully this is the right place for a question like this, if not I would really appreciate being pointed in the right direction because I'm ready to tear my hair out at this point.

For background - I have a Bissell stick vacuum that stopped working a few years ago. I assumed it was the batteries, so I took it apart and found that the unit is powered by 6 INR18650 cells that are not sealed, just welded with nickel strips and then soldered to the main board. I rebuilt the pack with new batteries and it worked... for about 10 minutes. I hadn't though about needing to make sure they were topped off or balanced and came to later find that the vac is able to sense an imbalance in the pack, but cannot recharge it - it just stops working.

To resolve it I bought an iMAX B6 LiPo Balance Charger on Amazon, soldered some leads to the positive and negative terminals, and connected up a 7 pin JST-XH connector for the balance charger port.

The issue I have is that when I try to start the Balance process on the charger it reports back
R: 5SER S: 6SER
Indicating it only sees 5 of the 6 cells in the pack.

I have done everything I can think of to sort this out:

1. Confirmed the JST pins are in the correct order.
2. Tested voltage from each pin (see below).
3. Confirmed continuity from BAT- to each pin.
4. Checked resistance from the JST connector to the battery terminal.

Here is a logical diagram of the cells with the voltages measured:

          BAT+ -----------------------------------● 
                                                  │
Pin 1  (20.28 V) ---------------------------------● 
                                                │ C │
                                                │ e │
                                                │ l │ (3.37 V)
                                                │ l │
                                                │ 6 │
Pin 2  (16.91 V) ---------------------------------● 
                                                │ C │
                                                │ e │
                                                │ l │ (3.41 V)
                                                │ l │
                                                │ 5 │
Pin 3  (13.50 V) ---------------------------------● 
                                                │ C │
                                                │ e │
                                                │ l │ (3.39 V)
                                                │ l │
                                                │ 4 │ 
Pin 4  (10.11 V) ---------------------------------● 
                                                │ C │
                                                │ e │
                                                │ l │ (3.40 V)
                                                │ l │
                                                │ 3 │
Pin 5  (6.71 V) ----------------------------------● 
                                                │ C │
                                                │ e │
                                                │ l │ (3.42 V)
                                                │ l │
                                                │ 2 │
Pin 6  (3.29 V) ----------------------------------● 
                                                │ C │
                                                │ e │
                                                │ l │ (3.29 V)
                                                │ l │
                                                │ 1 │
Pin 7  (0.0 V) -----------------------------------●
                                                  │
(MM COM)  BAT-  ----------------------------------●

I will readily admit that I have gotten myself confused and turned around when it comes to pin order. From what I am seeing in the instructions pin 1 (far right when looking at the connector end, with the lock on the top) is the positive end of the pack. That said, if I reverse the order I still get 5SER from the charger, it only tells me that the polarity is reversed it I swap the output ports.

From the measurements though, you can see there is some imbalance in the pack, but I get clean voltage measurements in the proper order from the pins, so I don't think its a bad connection. I also checked resistance from each of the pins to their respective battery terminal and none of them read above .3 ohms. I even tested on a 2nd B6 unit and it also reports 5SER for the pack, so I don't believe its a faulty charger.

I did see a comment somewhere that the B6 only supports a 6 cell pack in certain modes, but I cannot validate that comment anywhere in the instructions or online, so I don't know if I believe that claim.

At this point I'm all out of ideas, outside of asking Reddit I'm thinking I have 2 options:

1. Tear the pack down and charge each cell individually - but that's a PitA because they're all spot welded together.
2. Find a hobby or electronics shop that I can take it to and see if they can tell what I did wrong.

So, I would really appreciate any expert guidance you all could provide!

I made a mistake and need some advice. I have a 12V 42Ah lead-acid battery (Alaska A60L) connected to my solar setup. I poured about 200ml of normal saline water (sodium chloride solution) into 2 of the cells.

When the solar started charging during the day, I noticed a strange smell – probably chlorine gas. About 8-12 hours later, I flushed the battery completely with normal water and rinsed it out. I checked the voltage with a multimeter and it’s showing 12V.

So my questions are:

1. Does salt water damage the electrolyte instantly, or does it degrade over time?

2. Is there any chance this battery is still safe to use?

is it possible to check yuasa manufacturing date via these stamps?
so i bought the left one last july 2025 for my honda adv150 motorcycle, unfortunately i got stranded on the road because it was drained and as per battery tester it reach life expectancy. so i bought another one today and i was wondering if these stamps matter if im buying newly manufactured battery? the new one has stamped
1004269AD
1504690

while the old battery that got me stranded is
1804269W
2691590

Hello Community,

I can’t get it if the BMS is not working properly, or if I have done something wrong, or if it is normal (I doubt it).
Cells are mounted from right to left but I have wired everything accordingly.

Measured are:

B1- / B1+ = 3.9V
B1- / B2+ = 7.7V
B1- / B3+ = 11.6V
B1- / B+ = 15.4V
P- / P+ = 3.8V How’s that, shouldn’t it be 15.4V?