I noticed this battery had died when I went to use it. (Hadn't used it in at least a few months). The multimeter said there was 0v coming from the battery terminals so thought it could be dead bms or a few dead cells. I've since opened it up and I'm reading 0volts across all cells. I thought that was odd and was hoping for a second opinion?
accdently dug my pliers into the side a bit and it sparked then heated up and burned this hole through the blue should i countinue to use it?
I’m looking for good sources for ready-made Li-Ion 4S1P packs (18650 or 21700) for RC/FPV use.
Important for me:
-good cell quality
-real capacity ratings
-decent discharge performance
-preferably EU shipping
-XT60
Use case:
-FPV wing
-long range
-possibly gliders
Where do you buy your 4S1P Li-Ion packs and which stores would you recommend?
Just published my build for compact 5Ah 90A batteries, (BL1820 size) trying to find the right forum for it. Figured I would start here.
https://www.thingiverse.com/thing:7354748
Context: MBoards 6s2p INR18650-30Q 22.2V Nominal Voltage 30A Continuous 6S BMS
- Bought in 2019
- Is not currently taking a charge
- Was exposed to some water 6 months ago
- Was stored fully discharged from 6 months
- Had a short at the charging connector 6 months ago
- Was previously in a correct suitable plastic enclosure
- Was used for several years in a diy electric skateboard
- Has orange substance or something at the end of some cells
- AI (Claude Opus 4.7) is convinced its the cells leaking and refuses to help me troubleshoot further
- I am looking for a second (or third) opinion please
Can it be easily fixed ?
Can anything be salvaged?
What is the orange stuff, is it rust?
How dangerous is it in this current state?
Is it too far gone with the short, discharge and orange stuff?
Thank you in advance!
I got these 19 18650 batteries for free. No clue about the chemical conditions ECT. Most of them don't have any writing on them. I'm gonna measure voltage and then run them through my battery tester
Got this jetson e-scooter in for repair, can’t figure out how to get to the battery to test the battery & controller. Charger works.
0,15mm Laser cut copper sheets with 0,1 mm plated nickel
3D printed Cellholder JBD 100/300A BMS AwithZ uf20b Spotwelder
Copper busbars (I think 1,5x3mm thick) for the most part, at the ends I have 10awg split to both sides where they connect to AS150 connectors.
Build for my dual motor Ninebot G30 (100kmh) love the range and the power. Vdrop is minimal too, around 150mV per group at ~130a. Battery has also never gotten warmer than 30°C even when charging with 20a.
Hi, I wanna buy the mentioned cells, been checking both Alibaba and Aliexpress for them, they sell 2 versions, one has EVE logo blurred and the other has this EVE text.
They all claim cells are A grade and authentic and I kinda believe them, they also say EVE factory releases both versions.
ATM i can't find cells with EVE logo in stock, except for one guy who has like crazy 50€ shipping and the quantity i need is too low. Nobody else has them in stock either. Should I go for no logo or wait for full eve marking?
I could try with no logo and try to borrow that battery tester and if there would be an issue, I could open dispute, that is one way do go about it.
The replies i got from sellers: https://imgur.com/a/I5ghuPC
I have a pure air escooter 3 of the 30 cells are 0.0v it's still charges and works but at 37 volts I want to replace the 3 dead cells but I can't identify the cells for mha or amp rating so I would like you help on identifying them
as an absolute madman, I'm wanting to build a 30kWh monster pack for home solar storage (and another experiment that is irrelevant) and I did the math. I will have to put a total of 240 18650 cells in parallel to achieve my capacity requirement. does anyone have any experience with this sort of thing on this big of a scale? kinda need someone to look up to here for advice. I've done a lot of research to get to this point, so I know what to do, I'm just wondering if anyone's made it work before.
Hi guys! Thanks for taking a look at my post.
I'm working on a project: I want to reuse a thinkpad battery case. Turning a battery case and thinkpad internals into a docking station for a phone.
I wanted to use an already working powerbank, dismantle it: put the batteries into the battery casing and the powerbank circuits into the thinkpad case.
The problem is that: I don't know any good powerbanks that use 18650 cells. I need a passthrough!
TL:DR: Need passthrough 18650 powerbank, with 6 cells.
Hello. I recently got ahold of a couple of li ion cells and wanted to make a powertool battery for DeWalt from a kit I bought of aliexpress.
It comes with nice precut strips for spotwelding. I measured them and they are about 0.15mm for the connecting ones and 0.2 mm for the ones on the main + and - terminals.
What I am worried about is that they are listed as "nickel strips" I don't know if they are supposed to be pure nickel or nickel plated steel. I am not certain if they are sufficient for the connection.
Is there any non destructive way I can test that? If they are pure nickel.
I have a spotwelder that can do 0.1mm pure copper 0.1mm pure nickel sandwitch spotweld very reliably. Would it be worth trying to spotweld 0,1mm copper underneath the "nickel strip"?
If my spotwelder couldn't handle 0.2 mm nickel + 0.1 pure copper for main connections woul d it make sense to solder some braided copper onto the strip like the one used for solder wick?
The P20B has 3s 3v 1000F super capacitors which is 9v 333F
Could you swap out for 3 3v 2000f to increase to 666f? or run additional caps in parallel?
Hi everyone, need some help, both have the exact same specs & model number. A company claims that the red one is manufactured in Japan, while the green clearly says on it that it is made in China. Red seems less legit without all the text on it though, or maybe the text just isn't captured in the pic.
Would appreciate any help from anyone who can explain the differences.
There is also a brand called Nexcell that makes a 18650 battery, model S4737A, if anyone knows how it compares to Panasonic/Sanyo would appreciate any input, but I doubt it would be better than Panasonic/Sanyo & I've used Panasonic/Sanyo for over a decade without issue.
About a year ago I bought a used electric scooter for 150€. It was in ok condition but a bit of the battery has now suffered from water damage and I took the battery apart and ordered 40 new lithium ion batteries. The old battery pack had about 120 4,2V batteries and most of them are in good condition.
The only problem I have is that the old solder points could make it harder to spot weld the old batteries because of the old solder points. I wan't to try using a straight grinder with a non-conductive end. Is it a good idea, probably not but i've haven't come up with any other solution that is time effiecent.
Any ideas or solutions? It needs to be pretty flush so the current would not be limited
(Deleted the old post to change the title)
Pack would not take a charge. 2 cells were dead, the rest are perfectly fine. I got this pack for free from someone.
About a year ago I bought a used electric scooter for 150€. It was in ok condition but a bit of the battery has now suffered from water damage and I took the battery apart and ordered 40 new lithium ion batteries. The old battery pack had about 120 4,2V batteries and most of them are in good condition.
The only problem I have is that the old solder points could make it harder to spot weld the old batteries because of the old solder points. I wan't to try using a straight grinder with a non-conductive end. Is it a good idea, probably not but i've haven't come up with any other solution that is time effiecent.
Any ideas or solutions? It needs to be pretty flush so the current would not be limited
Are they all about the same?
Any reason at all to drop big money for really expensive ones like the SkyRC MC5000?
There is this Australian company Ohm Electronics that makes the A0292 if anyone has tried it:
https://www.ohmelectronics.com.au/collections/recommended-for-your-zebralight/products/a0292
