Lithium battery charging [Archive]

Finster101

06-10-2022, 04:16 PM

Several years ago I bought a Ryobi power driver and got two 18 volt batteries with it. Now the batteries will only charge up to 8.45 volts. If I leave them on charge longer they began to over heat. Anyone else have this problem?

You mention you got them several years ago. Are you sure they are lithium-ion and not nicad? Ryobi is one of the few companies that made the ion batteries compatible with the older tools. The newer batteries require a different charger. I went through the conversion and still have a bunch of the old blue tools using the new yellowish green batteries. It has also been my experience when a lithium battery goes my charger will not charge it if it does not pass a test when put in the charger.

Kraschenbirn

06-10-2022, 04:53 PM

quit charging them before you have a fire! Most likely have a bad cell(s), they have a finite life span especially with the abuse tool batteries get.

+1 on this!! I flew electric RC airplanes for a few years after I had to give up flying the real thing (because of a medical issue) and have seen several Lithium-Ion battery fires due to crash damage or incorrect charging. Believe me, they ain't no fun; other than burying them in sand or dirt, there's no way to extinguish 'em once they've ignited and they burn just about like thermite. I recall seeing a crash at an indoor meet where a battery lit off; the safety crew picked up the burning wreckage with an aluminum grain shovel and the battery burned through it before they got halfway to an exit. After one of the guys in our model club burned down his garage, I began stacking my battery packs inside a large ceramic pot set upon a concrete paver slab for recharging. This was back in the early days of L-I but even the latest versions can be just as dangerous, just ask any firefighters about their current training for electric vehicle fires.

Bill

Winger Ed.

06-10-2022, 05:00 PM

There's some magic number of how many times those new age batteries can be drained and charged.
It sounds like yours are just basically worn out.

I've had that happen with a couple of battery powered tools.
Replacement batteries cost almost as much as a new tool does that comes with new batteries & the correct charger.

Awhile back, one of the guys here was saying his electric car battery did the same thing.
Over time, the car would run less and less distance on a charge.

Like everything else in our society- including each other-- battery powered stuff is a throw a way when the batteries die.

bangerjim

06-10-2022, 05:33 PM

LIon batteries have over-charge circuits built into most packs. You cannot over-charge them. They do go bad but most are "guaranteed" for at least 10 years. Sounds more like NIMH or NiCAD batteries in the pack.

But only buy battery-powered stuff that uses LIon batteries (with correct charger!). Lithium technology is amazing. But just like you and I, they do have a finite life-span. I only own LIon powered tools now.

bangerjim

06-10-2022, 05:37 PM

Rechargeable batteries eventually wear out. Not sure about the current crop, but the recommendation from just a few years ago was to completely discharge them every time you use them, as if only partially discharged they will only recharge to that level in the future.

DG

That "discharge them" only applies to NICAD and NIMH batteries. Infact NIMH batteries are actually designed to gradually drain themselves to prevent that "memory" effect you are talking about. LIon's are totally different. I have LIon tools that have laid around for 2 years and still have a 100% charge! Amazing. Now if we could develop a technology that does not use metals from friggin' China!

GOPHER SLAYER

06-10-2022, 06:56 PM

When I wrote, several years ago, it was more like three or four. They are lithium with a different charger. What is nice about lithium batteries is they charge in just a few seconds. What is bad about them is the cost. At $40 each, you may as well toss in another $20 and get the driver as well. That is what I paid for the driver and two batteries. They were on sale of course, which comes around about every two months. I think I paid $97 for the package. Thanks to all of you who responded.

Randy Bohannon

06-10-2022, 07:03 PM

farmbif

06-10-2022, 07:19 PM

old electronics with lithium batteries made good targets, not the bang of tannerite but they get to burn

bangerjim

06-10-2022, 07:36 PM

No matter what generation of battery you are running do not leave them in the tool when not being used. One in the charger the other on standby and first used, leaving them in the tool for long periods kills a battery .

I leave all my LIon batteries IN THE TOOLS 100% of the time! Depending on the charger, the brand, and/or battery array, they do not like to stay on charger/plugged in all the time. I ruined several NICAD packs by doing that. I have left my several BOSCH LIon tools lying around for 2+ years (during China Virus times) with no damage to the tool or the battery packs. And they had 100% charge when I grabbed them to use them.

And there are many smaller tools & devices out there that the batteries are NOT removable! How do you address that?? Do you take the LIon battery out of your iPhone/Smartphone every night?

Nice thing about LIon's is when they run down, it's like falling off a cliff. They pretty much just stop and do not taper down in output like older technologies always did.

hiram

06-11-2022, 01:49 AM

There was an article I read about a problem with charging Ryobi lithium batteries and there were videos on Youtube about correcting the problem.

https://www.youtube.com/watch?v=p13iznXQNDg

jonp

06-11-2022, 07:09 AM

I also have a Ryobi tool kit with 18V batteries. They certainly have a life span. Without testing them I notice the battery life just decreasing down in between charge times and this also goes for the Hitachi battery tools I have. Stop keep using them if you want until they die but I would get new batteries.

As bangerjim said, charge them and set them aside for use. As an aside, I was just delivering zero turns to a John Deere dealer and saw some 82V Greenworks zero turns https://www.greenworkscommercial.com/82v-42-inch-crz-zero-turn-mower-7409502. Cuts up to 2 acres.

Also had a UTV https://www.greenworkscommercial.com/u500sb-82-volt-utility-vehicle-500-black. Runs 40 miles but I've seen some online that run 75miles. Interesting if you have power to charge them.

popper

06-11-2022, 03:31 PM

Some times the batteries can be re-juvinated by a complete discharge and then a slow start charge. All batteries have a 'memory' and limit on # of charge cycles. Run them ALMOST dry and then recharge.

Handloader109

06-11-2022, 04:58 PM

I just bought a new system on some hand tools. Had been using 12v Dewalt, but they are not Li ion, just older nicad. Went with Ryobi and their li ion charging instructions say do not charge to 100% if you plan on storing for long periods, but only partial charge. Charging to 100% gives best life if you charge before use. And these have a lifetime replacement. One thing no one else offers. We'll see...

Sent from my SM-G892A using Tapatalk

Rich/WIS

06-12-2022, 09:51 AM

Xmas before last my kids bought me several Ryobi tools, 18V. A month or two ago one of the batteries would not recharge so called Ryobi. The nice lady I spoke with had me tell her what the charger was doing and then give her the battery serial number. Three days later a newer style battery with a test switch to check battery power was delivered at no charge. Not sure what the battery warranty is but you might call Ryobi and see if they can help.

Scrounge

06-12-2022, 12:01 PM

Rechargeable batteries eventually wear out. Not sure about the current crop, but the recommendation from just a few years ago was to completely discharge them every time you use them, as if only partially discharged they will only recharge to that level in the future.

DG

The drain before recharging thing was, IIRC, only for NiCad batteries. Just watched this video a few minutes ago, might be of assistance for OP. I know I'm going to give it try, as my 40V 6ah battery for my Ryobi lawnmower & weedeater I bought a few years ago quit on me recently. https://www.homemadetools.net/forum/power-tool-battery-packs-video-91476?homelistings#post205057

HTH!

Bill in OKC

bangerjim

06-12-2022, 02:13 PM

NiCad technology was garbage, but it was all we had in the day! FAR better than the Zn/carbon/acid dry cells that were around for generation. They were always dead when you picked up the tool. And that memory thing forced us to buy new batteries every few years or so. You could "regenerate" some NiCad's by zapping them with a power supply of 2.5 volts at 8A DC. That seemed to "burn the shorts" out of them......ONE TIME ONLY.

Then came MiMH batteries and we thought it was the 2nd coming of the Lord. Heavy and cumbersome, they rapidly filled the gap created by NiCad's in industry. But those are actually engineered to slowly drain themselves over time! That minimized the memory thing, but you still ended up with dead batteries when you needed a tool. Every single time! And you cannot leave them on constant charge!!!!!!! That will also ruin them even faster.

Finally comes along the LiON battery technology of today. ( China and the Biden Crime Family are glad of that and the lithium consumption) Light-weight, fast recharge, and lots of power. They will maintain a charge for years and not deplete themselves automatically. The battery packs have built-in charge circuits that prevent overcharging and dead shorts. ( You do NOT want to dead-short a raw LiON battery + to - !!!!! It may explode or catch fire easily) That is why they have special chargers! You do not need to run them down. They will just quit when they reach a certain minimum % of charge, protecting the rather expensive batteries from totally running down and eventual damage. They do have a finite lifetime, just like you and I, but are far longer-lived than any of the old technologies you are all referring to up above.

Whenever possible I choose products and tools that use LiON technology. That is................until the NEXT battery technology comes out! If you want to know what they are, just search for "new battery technologies 2022".

kerplode

06-12-2022, 02:30 PM

Lithium batteries like to live in the 40%-80% charge range. Deep cycling them is hard on them and can reduce their life span. They don't develop memory like those garbage NiCads did, so no harm in charging them when they get to about 50%.

If you want to store on for an extended period, it's somewhat better to store them at 50% than at 100%.

matrixcs

06-12-2022, 04:09 PM

lithium battery packs can be rebuilt if soldering is your thing and you can save $$$ . I have dropped a couple packs and the battery's cracked and do not hold a full charge so I sent them to recycle and bought new. I have done it both ways but I am lazier now so new was my easy out...

brassrat

06-12-2022, 08:21 PM

I know the 18650 ? flashlight batteries will be destroyed if charged for too long.

kerplode

06-12-2022, 08:28 PM

lithium battery packs can be rebuilt if soldering is your thing and you can save $$$.

This is dangerous if you don't know what you're doing. The cells need to be properly balanced before you bond them otherwise the unequal voltages can result in a huge inrush current between the cells that can overheat them and start a fire.

Lithium cells are no joke and should not be taken lightly.

Randy Bohannon

06-12-2022, 08:46 PM

I leave all my LIon batteries IN THE TOOLS 100% of the time! Depending on the charger, the brand, and/or battery array, they do not like to stay on charger/plugged in all the time. I ruined several NICAD packs by doing that. I have left my several BOSCH LIon tools lying around for 2+ years (during China Virus times) with no damage to the tool or the battery packs. And they had 100% charge when I grabbed them to use them.

And there are many smaller tools & devices out there that the batteries are NOT removable! How do you address that?? Do you take the LIon battery out of your iPhone/Smartphone every night?

Nice thing about LIon's is when they run down, it's like falling off a cliff. They pretty much just stop and do not taper down in output like older technologies always did.

Read the owners manual on the Milwaukee, Rigid, De Walt, Ryobi, all say what I already said. Go at your own discretion. IPhones, small electric devices are disposable I don’t throw the tool away because a battery failed, I get a new battery. Little tiny batteries are not 18 -24 volt lithium batteries very different animals .

kerplode

06-12-2022, 09:19 PM

Little tiny batteries are not 18 -24 volt lithium batteries very different animals .

Yeah, not really. Guess what’s in that 18-24v pack? Same thing that’s in a 350v 75kWh Tesla pack…A bunch of little tiny battery cells wired in parallel-series chains.

gc45

06-12-2022, 09:33 PM

My shop is full of different Dewalt battery tools, some older 18 volt, some newer 20 volt and most all have the batt left in them and so far lasted us a good long time. My 20 volt battery grease gun gets used lots as we have both farm equipment and const equip always needing grease. Best tool ever!

bangerjim

06-12-2022, 09:34 PM

This is dangerous if you don't know what you're doing. The cells need to be properly balanced before you bond them otherwise the unequal voltages can result in a huge inrush current between the cells that can overheat them and start a fire.

Lithium cells are no joke and should not be taken lightly.

SOOOOOOOOOOO true!

Do not mess with rebuilds!

bangerjim

06-12-2022, 09:45 PM

Yeah, not really. Guess what’s in that 18-24v pack? Same thing that’s in a 350v 75kWh Tesla pack…A bunch of little tiny battery cells wired in parallel-series chains.

Absolutely NOT! Electric car and hybrid car batteries are made from a huge stack of ~1.5" thick rectangular cells. All lined up and series wired in a row.

301190

My Lexus hybrid cars have that arrangement. And carry a 10-year warranty. Never had a cell go bad in over 10 years.

Tool packs are made of normally round C or D size cells wired in series to get to to the voltage needed.

kerplode

06-13-2022, 12:01 AM

Notice I said Tesla battery?

Tesla batteries are comprised of multiple modules, with each module being constructed of many individual small cells…Essentially hundreds of what are basically 18650 cells.

Here’s a teardown of a Model S module:

https://youtu.be/UOi8m9m2YMI

kerplode

06-13-2022, 12:12 AM

This vid details the Tesla module architecture

https://youtu.be/bNd-yJtRPhk

And this one discussed the various styles of EV cells, their trade offs, and why Tesla chose small standard cylindrical cells

https://youtu.be/P7GR5fERXNY

popper

06-13-2022, 11:36 AM

The cells need to be properly balanced before you bond them otherwise the unequal voltages can result in a huge inrush current between the cells that can overheat them and start a fire.
Actually the cell voltage needs to be balanced, if not they will reverse voltage on the lower cell and batteries DON'T LIKE reverse polarity.

kerplode

06-13-2022, 03:42 PM

So driving current into the positive terminal isn't necessarily a bad thing (and doesn't really result in "reversed voltage" as you claim). This is how they are charged after all. But a controller in the charger monitors the battery and limits the maximum current into the battery to prevent drama.

The problem with parallel-bonding un-equalized cells is that the high battery will try to "charge" the low battery until the voltages equalize. Because the node connecting them can't sustain more than a trivial potential difference due to the DCR of the wire, there is nothing in this configuration to limit the current flow from the high-voltage battery to the lower-voltage battery but the internal ESRs. This is what I mean by inrush current.

In this config, the instantaneous power transfer can be well over 100W if they are very unbalanced. This much power/current will rapidly heat the batteries and can cause them to swell and or burst which can start a fire.

For a series configuration, cell balance is less critical in that it won't result in fireworks, but having them unequal will make the pack inefficient. A good pack/charger design will have the ability to rebalance the series blocks during charging. If you look at a dewalt pack, four of those pins (C1-C4) are the intermediate nodes between the 5 series elements. The charger can manipulate the voltages here to alter the charge state of the individual series elements, thus rebalancing the pack.

But for parallel elements, the voltage (and thus the charge state) balancing has to be done precisely before assembly otherwise there is a significant risk of fire.

bangerjim

06-13-2022, 04:14 PM

That is exactly why when I buy the "Tesla Battery Wall" for my 8KW+ solar panel array, it will be a commercial-built unit (not homebrew in my shop!) and installed and wired in by a licensed electrical/solar contractor. Those packs are very pricy and I am hoping the price will come down drastically with the advent of new and less costly manufacturing and packaging technology.

Friends ask me, with all my electrical engineering expertise, why I do not buy a battery system out of a wrecked LEXUS and build my own. No thanks! My home is just fine without a potential fire/explosion outside on the wall! :grin:

kerplode

06-13-2022, 04:53 PM

Dude, I'm with you! Even with 20 years EE experience, there's no way I would ever attempt to do a DIY home-build lithium bulk storage array. No. Way. This stuff is no joke. A Power Wall sized array contains a ridiculous amount of energy and can start a MASSIVE fire if mishandled.

Hell, it even makes me a little nervous to leave a good quality 18650 cell charging in a proper commercial charger. I don't buy cheap un-protected 18650s either.

IMHO, people are way too cavalier with these cells...

kerplode

06-13-2022, 08:16 PM

And since I guess we can only talk about Ryobi batteries:
The OPs pack has bad cells and needs to be replaced.

GOPHER SLAYER

06-13-2022, 08:34 PM

Moderator, I think we have found out all we need to know about lithium batteries, so I think you should put this post to rest and thanks again to all who responded. Glen

Mal Paso

06-13-2022, 10:20 PM

bangerjim

06-14-2022, 12:18 PM

I found this thread informative. As far as powering a house Lead Acid batteries are still much cheaper and the better quality ones last 16-18 years with care. I don't know that they have achieved that sort of life with Lithium but they probably will fairly soon.

Thanks!

Look up nickel-carbon rechargeable batteries. Those things are long-life and rugged. Not used much anymore from what I can find.

bangerjim

06-14-2022, 12:21 PM

And since I guess we can only talk about Ryobi batteries:
The OPs pack has bad cells and needs to be replaced.

OP - - - yes you have a bad worn-out pack. Just buy a new one. Please do not try replacing cells yourself if LiON. If you cannot afford a new one, take it to a battery repair place like Batteries+. They will advise and fix it if possible. And they know what they are doing.