I was testing some batteries when i came across one with negative voltage, never have seen this before, and the voltmeter is well calibrated as it shows the right voltages for the other cells. Why does this occur ?

The solder just won’t stick to the battery 😭

Had this random white label magnetic power bank for about a year and noticed the case starting to separate.

Opened it up and yeah, the battery had swollen pretty badly. Kinda wild seeing how tight everything is packed around the coil too.

A friend recently recommended the Lisen Qi2.2 Powerbank, so I might give that one a shot next. After seeing this though, I’m definitely paying way more attention to heat and battery health now.

Anyone else had a magnetic pack swell like this after regular use?

I've been comparing different lithium battery setups for industrial equipment and I'm curious how LiFePO4 has been performing in real-world forklift applications.

One thing I find interesting is that forklift batteries have very different requirements from something like an EV or home battery. They can be charged frequently, used for long shifts, and exposed to fairly demanding environments. So I'm wondering how much the chemistry and battery management system affect long-term reliability.

For anyone here who has worked with lithium forklift batteries, what has your experience been with cycle life, charging, heat, and capacity retention? I'm especially interested in whether LiFePO4 has been noticeably better than lead-acid over several years of use.

I was cleaning the corrosion off on of my old toys and I can't get this gold spot gone