EEVblog #919 - How To Charge Li-Ion/LiPo Batteries With A Power Supply
Why Electrical Engineering Stack Exchange recommends it
Electronics Stack Exchange users cite it as the reference for charging lithium cells from a bench supply when a dedicated charger is not available.
Recommended by 0 people across 0 different months, 2017 to 2022.
What it is
Dave Jones of EEVblog shows how to charge a single Li-Ion or LiPo cell using an ordinary bench power supply set to a constant-current, constant-voltage profile. He uses an 18650 cell's datasheet to pick the current and voltage limits and warns about the risks of charging unprotected cells without a proper charger.
What people said
Cites Nick Gammon · 2017-10 · Electrical Engineering Stack Exchange · on “What temperature should a LiPo battery reach during charging?”
I was attempting to charge a LiPo battery using a bench power supply as described by Dave Jones [this video] . The battery is a PowerTech 18650 2600 mAh 3.7V model SB2308. The datasheet appears to be here [LINK] . The relevant part of the datasheet is: [LINK] I didn't quite understand the charging rate of 0.2C5 A - would that be 0.25 C (650 mA)? I thought that, if you used the units symbol in the middle of the number it would be at the decimal position (ie. "0C25 A"). To be safe I charged at 0.2C (520 mA) with the supply configured to switch to constant voltage at 4.18V. I charged for almost 5 hours, monitoring the voltage, like this: [LINK] However at the end of that time I noticed that the cath
Cites MicroservicesOnDDD · 2019-01 · Electrical Engineering Stack Exchange · on “Why the actual charge current of a battery is not improving when I shifted to larger current capacity battery charger power supply?”
More Cells in Series Enables Full Current Charges If you need faster charging at the upper end of the voltage range, you may have to use a different configuration, such as 2S1P, 2S2P, ... The 2S part is 2 cells in series. The nominal voltage in that case would be 3.7 x 2 = 7.4 volts. So, to charge really fast, right up to 4.2 volts, which is the typical max, you actually have to be able to charge up to the 8.4 volts (4.2 x 2), or even 3S at 12.6 volts (4.2 x 3). Nearly-Charged Batteries Charge Slower in Constant Voltage Mode Most likely, you have a low charging current because the constant voltage part of the charging curve has already kicked in. This actually means that your cell or battery
Cites Gaweringo · 2022-10 · Electrical Engineering Stack Exchange · on “Is it possible to use a Li-ion power tool battery while on a charger?”
My plan would be to use a 20 V (x2) power tool battery [LINK] with a step-down converter [LINK] to power a 12 V radio. I would also like to be able to power the radio from the wall through the battery charger [LINK] , similar to how a UPS (or laptop/phone) work, so the question is, is this possible? Can I put the battery on the charger and connect the DC/DC converter to the leads of the charger that go to the battery to operate seamlessly on wall and battery power? I have looked around a bit but am still not sure if this would or would not work. On Reddit, I found this [LINK] , which would describe my situation, although I am not sure if the BMS shown there is how my battery works. Or more s