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Thank you for doing this, you helped me found my business 10 years ago and I really wanted to thank you.. I was able to do so much without having gone to school because of your videos.

this guys amazing and very knowledgeable​. although he looks to have been filled with a couple hundred volts over time himself.thanks for the great videos.

I love the way the Aussies talk! :) All happy and positive 👍🏻

Im 16 years old and ive been building all kinds of circuts and started using embeded processors like the AVR's not to long ago and I just wanted to say that I love your blog and its helped me so much with learning all these concepts :) so thanks for all your doing and keep it up.

Thank you! I had very little knowledge of the charging characteristics of lithium ion cells. I watched a couple videos on the topic and came away confused. I didn’t know there was a constant current charge cycle followed by a constant voltage charge cycle. As always, I thought you explained it extremely well and I easily understood what you were saying. I have often said, how much you learn is not as dependent on how smart you are but how smart your teacher is. Thank you!

I come back and rewatch this when I'm getting fuzzy, Dave is the best.

Actually past Dave, Li-poly are different from Li-Ion. Poly cells are prismatic and typically for high drain applications up to 30C, while most ion versions are for lower drain applications up to 20A and are usually manufactured as cylindrical cells

@vaneenbergen I totally forgot to mention the protection circuit built into the bigger cell I was waving around. You really should be using these protected cells, they protect against shorts, over-discharge, over-voltage etc. With the unprotected cells, you have to take more care, and either add your own protection circuitry and/or design your product properly to ensure the battery is not abused.

Overall Your videos are awesome, thanks - helps a lot! :) But story behind Li-ion, LiPo and LiFePo is a bit different. Li-ion: Vn = 3.6V (uses transition metal ion eletrolitic compound) LiPo: Vn=3.7V (uses synthetic polymer compounds as eletrolite lowering internal resistance... this is where +0.1V in avg comes from) LiFePo: Vn = 3.3V (same synthetic polymer compound as eletrolite + different anode that changes reaction electrochemically itself).

Minor remark: charging is never exothermic with respect to the charged battery. The heat production comes from energy loss, the energy coming from the charger. Charging must be endothermic, because the chemical reaction to deliver energy necessarily must be exothermic. Great explanation and great videos, BTW. Thanks a lot.

Seriously appreciate the content as an aspiring creator / engineer trying to learn on my own. Advice is top notch. Bloody good channel and keep up the great vids ❤

Dave Jones you are my favorite RU-vid personality. I would follow you anywhere. I only wish that I lived in Australia because then I would ask if I could be shop boy. I would sweep floors, scrub toilets and dismantle electronics for you. I would work for beans and biscuits. I would put a cot in the broom closet and call that home. Is it true that you have a locker at the bottom of the sea where pirates disappear to?

"You really should know because it's interesting." Love it! :D

Those Microchip chargers look quite a good deal for a simple application. thanks for the video Dave.

Love the video, Dave's back! Please keep up the long videos like this, this information, level of detail, and overall information is not easy to get elsewhere. I always feel like I've learned a bit more after watching one of these, please keep it up!

Li-ion and Li-po do have a difference now some Li-Po have higher charging and nominal voltages and they are also also available in large capacity pouches where as li-ion are not and they have higher C ratings much higher compared to Li-Ion

@chrisgj198 That's probably a separate blog on it's own, low battery detection and cutout. And that applies to any battery technology really.

Best Video for understanding Lithuim Ion Charging process. Thanks Alot. Hope you upload Many more such videos dealing with electronics Stuff

Willy Wonka and the Electronic Factory. Joking around aside, this is a very essential video, helped me a lot. Thanks!

Digital camera batteries for popular camera models can be a nice cheap source of ready-packaged batteries. Ditto camcorder ones, typically 7.2V, and also phone batteries. Just be aware that clones tend to have 10K resistors instead of thermistors...

Very helpful kickstart to my understanding of lithium Ion charging. Thanks!

@bcsupport You can get charger ICs for multi-cell packs. I've used a Microchip 2-cell one in the past

you're amazing thank you allllloooot i was looking for such understanding from a long time

Yes, I totally agree. Dave, Im going to have to start donating with these real world tutorials

Hi, im from the future! Thank you for this retro lithium based batteries tutorial, now days we just use flux capacitors.

Can you explain please how balance chargers are implemented for simultaneous charging to cells in series? Component level explanation as shown in this video would be appreciated.

Dave, we can always rely on you for very solid material, like this one, on Electronic Engineering. Thanks very much. Keep them coming. Question: 1/ In a charging system, like say on an Electric car (Completely Electric), where REGENERATIVE BERAKING charges the battery, how is this possible? Since, during the REGENERATIVE BERAKING charging process, the battery is still supplying power to operate the various systems on the car (i.e Lights, radio, the Mini fridge with the cold drinks etc). I would be very grateful if you could explain how the battery gets charged during breaking AND if possible, point me to any in-depth detailed reading material, and 2/ Would this explanation apply to other battery types such as Led Acid 3/ Where could I find in-depth detailed information on Lead Acid Battery charging. Thanks very much.

Damn, when I read the discription, I was all like "this is EXACTLY the info I need". Timing couldn't be better, Dave. Going to enjoy this one. :)

@blackmuzzle You can't just make that blanket statement that "modern cells" have no problem. Read the datasheets for all those Li-Poly cells I showed. 0.5C recommended as standard charge, 1C absolute maximum for "fast charge". Always read the datasheet, cell types and their recommendations are many and varied. Yes, some are specifically designed for very fast charging. The price you pay will usually be cell life.

That was exactly what I needed. I'm interning at NASA and we're building a prototype lunar lander and rover that powers a Li-Ion/Li-Po off solar panels and we were having trouble charging and some other things. I have a question though: Why is part 2 of the charging process (I believe it's called trickle charging) necessary? Why can't you just charge using the part 1 method up to 100%? Is it a safety thing, an efficiency thing, or something else? Thanks

super later to the lipo battery thing. Thank you for your video and breaking it down for me.

It's been 11 years since this video was posted and I'm here because I've never built a charger before and I want to learn how.

Great info Dave!! cheers for your efforts!!

Hey Dave, will this method work for RC lithium ion battery packs?

He is great! Thank you very much for the great tutorial. To the point and enthusiastic

If you could explain the working of the controller in detail, that'd be awesome!

@TheCrazyInventor Yes, I totally agree. Dave, Im going to have to start donating with these real world tutorials

Thank u so much.This is a great tutorial.This solved all my problems about Li-ion/Li-po battery charging.

You can't push the cell to higher than 4.2V without damaging it (which might make it go bang). Unless you use a ridiculously low charge rate the cell will reach that voltage before it's 100% full. As the battery charges its voltage gets higher, so to maintain a constant current you have to keep raising your charge voltage. Once you hit the voltage limit you can't raise it any more, so the current starts to reduce and the last few percent takes for ever.

Wow. Totally helped me out. Fixed me a wireless speaker but in turn, the charger circuitry died. Now I can fix that bad boy.

@bcsupport Most chip manufacturers have devices designed for more than 1 cell. It's usually an option in the parametric search table. You can't just use a single cell charger chip with those.

The main thing that is reducing the capacity is the discharge rate. The difference between 1C and 2C discharge is about 3% for 300 cycles. Of course, this differs between batteries also.

Min 12:00 , what i dont get is . Does the battery voltage increase because the charger increases the voltage ? Or is the charger applying 4.2V constantly and still the battery voltage increases just slowly ?

"the other kind of coke"

Man it’s crazy that we’ve been using Li-Ion and Li-Poly for 10+ years.

One thing to watch is power dissipation on the linear chargers - at charge currents over a few hundred mA, you don't need too much input-output voltage differential before the charge time gets extended due to the charger going into thermal limiting. Most of the cheap ones aren't packaged to conduct heat out well.

Lithium polymer is different to a standard lithium ion battery. Li ion polymer has a plastic electrolyte, while lithium ion batteries have a liquid electrolyte.

very informative.......for my phd work.....thank you for this wonderful video

@vaneenbergen Lithium Ion Polymer are more robust than Lithium Ion. But if you are really concerned, try LiFePo4 as @Pook365 said, they are much safer and won't go exothermic.

@vaneenbergen When used properly their dangers although real are very unlikely to ever be encountered. You could always try LiFePo4 batteries instead as they are more or less safe. IC's are available to charge those from Microchip (I presume other ppl as well) I've used the MCP73X23 but they do a couple of others to.

All circuit diagrams are super simple for this guy!😂

Man now I want to try some of those batteries, especially the bendable one.

great video - this topic probably needs re-visiting.

Haha I had to google "Bob's your uncle". Great stuff!

What it the best way to charge Lithium-ion batterers to maintain the life of the battery in a device like the 7 inch Kindle Fire tablet? By battery life, I mean the life of the battery before it will needs replacement. Some say it should be completely discharge about once a month. However, I also heard that is only valid for the old nickel-cadmium batteries.

@bcsupport You can also get IC's for 2S (the MCP73842 for instance). I've no idea past that as that is the highest I've had a use for :)

All Lithium ion polymer batteries are lithium ion batteries, but not all lithium ion batteries are lithium polymer. Those which are not "polymer" are the ones which catch on fire because the electrolyte is so flammable. In polymer electrolyte batteries, the electrolyte is bound in the polymer.

thanks Dave! that was pretty easy.

So we drone pilots are overcharging our "lipo batteries"? When you see what a lipo vs a Li-ion can do with respect to power output on a drone, then you might concede to the difference we see. I charge mine at 4c when out in the field to 4.2 per cell. Why then do all universal battery chargers differentiate lipo and lion? In my experience, lipo can dump far more power instantaneously and not be destroyed.

What about safety issues with Li-Ion? this is what's keeping me from using them. a nimh will just vent when over charge, not explode.

As always Great info.

If you took a Li battery out of an old electronic device how do you find you what kind of Li battery you have? the one I found didn't have any specs on it.

My IMax charger has a 3.6V setting for LiIon and 3.7V for LiPo, so surely there is a difference?

I haven't had a chance to watch the video yet but do you have any books, eBooks or websites that you could recommend that i could learn more basic electronics than what you do?

@34:35 The 'Charge Complete' leakage current listed is _negative_ - a.k.a. float charge.

Excellent Tutorial, Thanks!!!

Alot of youtube videos shows how to build batterypacks and how to charge them. One thing I don't find an answer on is: If I build my own charger for a batterypack, should I treat the entire batterypack as 1 large battery, OR, shall I treat each battery in the pack as individuals, and adjust my charging accordingly for each individual battery? :)

Dave you look so young! I didnt have white hairs either back then XD

Once I fryed my Charger. switching it on while 3 cell battery connected. smelld Funny and Expensive

Hello mate! Saw the entire vid and it's excellent. Amazing talent for explaining things you have. Now, would do please do a similar video explaining how QUICK CHARGE works? Various manufactures implement their own way of charging quickly, but I am more interested in those who do it using higher voltages. For instance Qualcomm's Quick Charge 2.0 and 3.0, it charges the lithium battery at 9 volts sometimes at 12 volts even 20 volts... It charges at 9/12/15/20 volts during CC and CV times.. now, how's that possible?

You are like the Raw Papers guy but with electronics. (doesn't matter if you smoke or not just check him out, you won't regret watching any of his videos)

It's pretty simple on paper but I'm having a super hard time finding a 250mA charging board that doesn't require me to replace an extremely small resistor to set the current.

Thanks! It's helpful a lot. It's better to tell the formula of this circuit.

. I also found the following when I googed: "For proper reporting of the battery’s state of charge, be sure to go through at least one charge cycle per month (charging the battery to 100% and then completely running it down)." To me, the above means for proper reporting of the how much charge is left in the battery, not to make the battery last longer before it need replacement. Am I correct?

I probably missed it, but is there a maximum amp hour limit for charging? Like if you had a charger ment for one battery but you put a 100 batterys in parallel what would happen?

Why is my 48V ebike battery only rated at 5A max. charge current when discharge is rated at 20A max?

Great explanation

Cool Vid Dave... I miss the old Dave, the new one doesn't have the same fizz as he did in the old days.

Excellent, you should have a shot at becoming a lecturer.

Some say there is no problem leaving the charger connected, even when in use, the charger regulator in the device will protect the battery from being over charged. Is this true? Also, will the device like a Kindle Fire use the charger's for power and not the battery, thus extending the live of the battery before it needs replacement?

Presuming it’s fine for the alternator, can you use an alternator directly as a charger for big lifepo4 packs? It puts out a Constant voltage of 14.6. And current is limited to 100 amps. It costs a lot to get a 100amp ic

Thanks for explanation. Well done!

Yes it is in the phone.

What happens of you charge at lower currents than 1/2c The generic power bank charging mpdules only put out about 1 amp While the batteries used are usually 2000mah or 3400 mah 18650 type batteries in parallel.. Giving capacities ranging from 5000mah to 20000 mah It will charge slow, but what impact does it have on the life span?

awesome vid! i was woundering is it possible to charge li pols off a solar panel and what kind of electronics would be involved. thanks

Hello, your demonstration is just perfect (as others) I am trying to "revive" LIIon batteries for portable vacuum cleaners, they where not used but they are old now (exposition models) I am not sure, if I plug my CC CV alim directly on the battery elements, may I use for instance 20% of the total voltage and 10% of the charging amp ? I tried on one cell as on the whole group and I see no amps asked by the batteries, nothing happens, SO there is no charging at all I suppose ? Thank you and sorry for the may be stupid question.

Dave, I realise you may not have time, but I'd love you to look at these "hemp batteries" that supposedly outperform lithium ion. Is that for real? Could you verify some or put them on test?

Beautiful man.

So what if your charger is only constant voltage?

My battery has 3 terminals and is for a Wacom PTH-851 graphics tablet. How can I utilize the 3rd terminal in charging Li-Ion batteries???

Is the Charge Protection built into those tiny Li-Po cells, usually covered by yellow tape, the same as the Battery Charging Chip you talked about? As in, if my Li-Po cell has built-in Charge Protection circuitry, can I just connect it straight to a 4.2V power supply and expect it to charge correctly on its own? (You may have mentioned this in the video, in which case I missed it...)

Dear David, The video is very helpfull and informative to me. Kindly tell me if i want to charge a 30AH/ 12.6V or 12.3V Li battery pack which IC shall we take. Thanks and Regards Deepak Kapila

EEVblog I would love to hear what you think about parallel charging of LiPo batteries which is shown at Lipo Batteries - Parallel Charging What about parallel charing of other kinds of batteries like NiMh?

Very helpful! Thanks again..

How do these chips detect the true battery voltage during charging? I thought the battery voltage when there is a charging current and the battery voltage when no load is applied is different.

C= 1Ax1s Charles-Augustin de Coulomb, unit symbol is C "charge" am I right or not ???

and one more question - If i want to use the product while it is charging, will it matter? i mean will it mess with the charging process?

Hi, thanks for this useful video. I have a question about LiPo chargers. What would is the difference between a normal LiPo Charger, for example, four cells, and a Balanced LiPo Charger for four cells. I mean, is there any difference for the lifespan of the cells?

ps i need help my xperia z not charging and wont turn on.?.??

I just bought a 'hoverboard' that has a 42v battery pack (I think its 20x18650). The board was hardly used and the battery died and is now showing only 3.1v. Is it possible and safe to recharge this?