EEVblog #919 - How To Charge Li-Ion/LiPo Batteries With A Power Supply

How to safely charge Lithium Ion & Lithium Polymer batteries with a bench power supply, for when you don't have the correct charger available.
WARNING:
Take care using PSU's for charging unprotected cells. A fault in the PSU might overload or short the battery & that could be dangerous.
Always watch your battery during charging using a general purpose technique like this.

Lithium Battery Charging Tutorial:

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[TechnocraticBushman]

Says short video, keeps it a little under 14 minutes. Says he's not doing an tutorial channel and manages to be a top resource to go to. Pure gold! You can almost get 20 years worth of EE experience just by listening to Dave going into all the little minutia. You can actually get a "feel" for this stuff and feel confident enough to do build your own charging circuit just by watching this video.

[EEVblog]

Sorry for the re-uploads, I wanted to remove most of the the voltage drop stuff to avoid confusion and constant emails and messages and comments for the next 5 years.

[ianhosier]

I have been charging 18650 cells on my lab supply for years. Set the current to 1A and the voltage to 4.2v per cell. Stop charging once the current is reduced to 100mA. Sometimes I charge overnight with a current limit of 250mA and again stop the charge when the current reaches 100mA. I have started experimenting with TP4056 modules which automatically stop the charge which is quite handy for unattended charging.

[kmonyt]

Nice video. I've got a Rigol DP832, no doubt because you've shown/reviewed/talked about it here. A video showing how to use some of the advanced features would be useful to me! Many of these devices are similar....the concepts would transfer to other makes and models...

[bradleymorgan]

It's been mentioned, but military tech only charges lithium batteries to 3.9v. Maybe 80% of the capacity, but close to 5 times more charge cycles.

[robertvaldimarsson]

Rigol actually has an app note, warning you not to hook up batteries, without at least a diode as protection, since the DP832's inputs are apparently very sensitive to being fed with voltage or current.

[kaizen]

I liked how you repeated certain parts of the video Dave. Like when discussing the graph. This is really really helpful for people like me who struggle to learn these ideas.

[backpropagated]

Thank you! I spent $400 on a drone, and didn't buy a lipo charger because I thought I had one. This will get me buy until Amazon gets one to me!

[gionnic]

Nice video! Thanks!!
Any chance you could do a follow up or give a base explanation of how to charge a Lithium ion pack with cells in series and parallel?

[tohopes]

You could put your power supply on a cheap outlet shut-off timer if you didn't have a fancy expensive power supply.

3:20 I'm commenting on that 3.5-inch digital multimeter again.

Watch out for that first step, it's a doozy.

[OfflineSetup]

can I suggest a second video where you explain the problem of the original?

[bilaloz]

Also do a how to safely discharge video please, cheers !

[alextrofimov]

It's so simple, but I've never thought about it! Thanks)

[MarshallSmith]

I'm about to buy my first power supply. I will be charging the occasional cell with it and powering amplifiers and small circuits. Should I be looking for Linear or Switching?

[IsaacOLEG]

I did read that Lipo batteries are more dangerous to charge without a specific "balancing" charger . Then may be some balancing circuitry exists in my battery pack, not only a heat sensor and constant current constant voltage circuitry (?) I did unsold it from the batteries to be sure of what happens) thank you

[ab_ab_c]

The safe max charging V for that Panasonic cell = 4.25V
The recommended charge cut-off A = 65mA (which is 0.02C, not 10% of the CC).

Thanks for sharing.

p.s.: If you want to get max cycle life out of the cell, it is recommended to charge it to a max V of 4.1V & not discharge it more than 20% when using it. >= 50% DOD really creates a significantly shortened cell life.

[jockemustafa]

Thanks for uploading this. This made me finally charge my Canon camera LP-E6 battery with a constant current on 650mA and when reaching the maximum voltage of 8.4v i changed over to constant voltage and see exactly the same where the current starts dropping! Wow, i really need the camera tomorrow and you made me do it! Best youtuber EU! (i know you're not in the EU)

[FrenchmansFlats]

you are missing a heavy schottky diode on the charge circuit (like a SR360) to protect the supply from reverse polarity on the Li battery.

[TonyLing]

Nice one again Daveo, totally trusted content. The absolute best.

[Hadcrash]

I remember when Chris Boden of The Geekgroup kicked me out of their IRC for explaining how you do this. According to him it's insanely dangerous and should never be done. He seriously knows fuck all about a lot.