The most over-looked lipo charger spec: Balance Current

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Balance current might be the most over-looked lipo charger spec. Everybody focuses on watts and amps, but if your charger's balance current is too low, your whole charging process can come grinding to a halt.

[jdbergan]

You can tell how truly professional he is when he let out "suck it off" and didn't crack a smile

[brubakerjm]

1) Watched video
2) Downloaded manual for my charger
3) Saw balance current rated at 200mA
4) Slammed face on desk
5) Bandaged face
6) Started shopping for new charger...

Thanks, JB! I didn't even know I needed to learn something today...

[XZLRN]

This has made me rethink all of the cheaper chargers I have and answers a lot of the "why is this taking so long" questions

[McDroney]

I've been in the RC hobby for 20+ years and EVERY SINGLE time I watch one of your videos I learn something new - keep up the fantastic work!

[vacatedbroom]

The straw analogy makes so much sense now, and the sucking sound just makes it so much easier to understand exactly how the stored energy leaves the battery

[cameronlatulippe]

I know literally nothing about batteries and charging but getting into RC racing. This video is awesome thanks my man.

[FreelojoFPV]

Hey this is Joe's wife, nice video. I love the time and work you take into explaining how things work. Especially from your point of view. I'm a big fan. Hugs. Much love

[johnfaustus]

Note: some manufacturers and retailers (like ProgressiveRC) use the term "Current Drain (Balancing)" to list what you refer to as 'balance charge current' - their terminology is more accurate than yours since the full cell(s) are actually drained when topped off whilst the other cells are being charged. On my 4010Duo, for example, it is 1.2A and 2.4A).

BTW, the reason battery balancing of cells works this way is simply cost and safety. Rather than maintaining 4, 5, 6 or more charge paths (or whatever S rating your charger is), each needing to carry a non-trivial amount of current as well as sense circuitry to monitor voltage, it is easier to just dump energy into a an R-bank per cell.

[fredrikisaksson]

Hey hey hey JB!!!!
You can't just look at the current.
You MUST look at the POWER you can discharge.
If you have 6cell you can't use the entire 1.5A in your case.
Say your battery have 25V, you can only discharge 0.6A.
15W/25V=0.6A, looking at the charger in this video.
I have chargers with a maximum discharge of 5W, really low current when the voltage is high.
The same goes for charging, maximum watt.
Higher voltage the lower the current, and vice versa.

Thank you for great videos.
Keep up the good work informing the comunity.

[cognetic]

Holy crap! I actually learned something today. I had no idea it was sipping. I did assume it was pumping.

[thedarkrs]

Great video JB.
Just a small clarification,
Most chargers start balancing while charging, they dont wait till the end, before the battery is full, the cells are already balanced so they reach 100% SOC at the same time.
Also, the charger doesn’t “suck” current out of the cells, it just shunts the charge current past the full cell.
If you put an amp meter on cell, you will see that no current flows out of it, if it did, the cell voltage would go down, and it never does, it reaches 4.2 and just sits there.

[pixelfaust]

4:52 The memes are gonna be strong with this one

[austinsmith]

It legitimately took my charger 27 hours to balance a 4s 6000mah li-ion battery that I forgot to balance the cells before assembling it. Balance current definitely matters!

[MadDragon]

How did you get so smart? I'm mean...
My entire life people came to me for answers and yet when I watch your videos I feel like a student that doesn't want to leave class.
Freaking amazing!

[Neukom]

icharger 406 Duo FTW! 40 amp discharge per side 70-80amps if you combine both channels also can do regenerative discharging into my 2x120wh deep cycle batteries, don't buy cheap, spend extra and buy 1 time, have had this thing for years and it's freaking the best even has sd-card logging!

[russsmith]

Like you said, I’m gonna learn something today. Not every day, but today I did! I’m actually in search of a charger that will do 5000 plus mAh 6s packs for my boat and my quad so That’s going to help me in my decision making of the charger tremendously. Thank you sir. 👍👍

[jiml]

That is very interesting I have never heard this mentioned before.
I now understand why the Hitec X4 (300 mah balancing) took forever.
I quite flying three years ago, still enjoy the videos.

[timothydurr]

Josh as always great video, I have searched youtube with no success maybe you can help me, and a thousand other retired seniors that are not so computer savy! I have been flying fixed wing for 40 yrs and a couple yrs ago i got a tiny whoop and have progressed to doing a small amount of tuning with some success because of you and your how to video's, recently I discovered the DJI mini 2, I want so bad to buy one but I know absolutely nothing about recording anything to a micro disk much less playing it on my computer (chromebook) and it would be even better if I could share a video. Believe me when I say there are a lot of us in need of someone to take us by the hand and lead the way, of course I think this would make a great series of video's for people like me who want to but just don't have the know how. Thank You Josh keep up the good work.

[michaeldavis]

Explained this so well, I have cell imbalance on 3 x DJI TB47S batteries, just need a video from you now to explain how I can bypass the smart charging circuit board on those and start properly balancing my cells. Keep up the great work

[RocketBones]

Your ability to explain unfamiliar topics in a manner which I can instantly understand - is such a gift. Thanks man.