Care and Feeeding of Li - Ion Batteries?

[Telly]

I have my first-for-me Lithium - Ion batteries. Bigger batteries, they are 40 Volt 73 Watt/Hr pluggable battery packs for outdoor power tools that were specifically designed for them. Came with their own AC chargers.

Just about no useful info about the batteries themselves, other than the usual generic safety warnings.

I'm well-versed on Ni Cad batteries, all the way back from the 1970s to recent. But the Li-Ions are new for me.

All my battery drills are Ni Cad, and they came in plastic cases that have places to store the charger and two batteries, so they are easy to store inside the house. But these outdoor power tool Li - Ion batteries and chargers too, are pretty big. Running out of good places to put them.

One of the Li - Ion tools is an extendable hedge trimmer, which I will use rarely, and only for a little while when I do (but it saves me from being up on a step ladder on uneven ground that slopes away, doing a ballerina balancing pose while holding a corded hedge trimmer by one hand and reaching waaay out, so it's worthwhile!).

I was thinking of leaving the battery for that one on the tool itself, it seems to balance nicer on the bolt that I drove into a stud in my garage wall. Nothing in the instructions say not to leave it on the tool. The battery on that one as hung is about a foot from the ceiling, and this is in Texas, driving a car in later in the day will increase garage temp even more for a while. Instruction book says charge between 45 and 104 F., that is the only mention of temperature.

Suggestions on the care and feeding, and storage?

 

[Lsbcal]

I have 4 tools that are use 20v Li ion batteries. They are a drill, hedge trimmer, and extendable hedge trimmer that tilts too, and a leaf blower -- all Black & Decker. Have had them for maybe 2 or 3 years I think. The batteries are always in the tools and kept out in a garage that regularly sees hot temperatures in the summer. When I use the tools they have functioned very well with no battery issues. I charge the batteries in my kitchen area when required. The charge cycle is reasonably fast, maybe 3 hours or so but I haven't timed them since I have enough batteries to get me through any job. Actually, to avoid overuse injuries, some jobs are better split up into maybe 1 hour tasks.

It's nice to have a few batteries especially for the blower which sucks power pretty quickly.

 

[ERD50]

This is usually a good source for battery info:

How to Prolong Lithium-based Batteries - Battery University

I just glanced, but I think I'd avoid storing them in a hot garage.

-ERD50

 

[Lsbcal]

I notice that to buy another Li battery for my B&D would be about $37. So if I have to replace a few in several years it won't bother me. One might loose some charge storing at higher average temperatures but with extra batteries it's not really an issue.

Battery technology may get better anyway so a few of these tools might get replaced. My 20v Li blower is much better then the 18v NiCad it replaced.

I do take care to charge in the house on a kitchen tile counter without flammable items near it. Just in case one decides to start smoking ... which I have no idea if it is possible but my imagination can conjure up an image.

 

[ERD50]

...

I do take care to charge in the house on a kitchen tile counter without flammable items near it. Just in case one decides to start smoking ... which I have no idea if it is possible but my imagination can conjure up an image.

On some of the RC forums, they place their batteries in a 'sand box' when charging. Not a bad idea. One guy was clever, he put some sand in plastic bag above the batteries - heat would melt the plastic and dump sand on it.

I do try to charge on a metal or cement board scrap, but I should be more consistent in that.

-ERD50

 

[Walt34]

I just glanced, but I think I'd avoid storing them in a hot garage.

-ERD50

Me too. They're used extensively with electric R/C models and I've read several stories of batteries catching fire or even exploding during charging or shortly afterward. Batteries of any type and high temperatures do not play nice together. For R/C anyway the mantra is be nearby when it is charging and put it in a ceramic container.

This is a link to what happens when li-ion batteries are abused. I really don't want that going on in the house or even garage.

https://www.youtube.com/results?search_query=lithium+ion+battery+fire

 

[Lsbcal]

I took a look at those youtube titles. People fired bullets at Li batteries, poked them with knives, hit them with a hammer, short circuited them, overcharged them, etc. Nothing I'm planning to do but maybe if I'm bored I'll shoot one with a 38.

 

[Lsbcal]

Today it's 101 F at our house. Went out in the garage and it felt mildly warm there but I just can't imagine this setting off a battery explosion.

I store all kinds of stuff out there like 2 cars with flammable fuel still in the gas tanks and those big car batteries all charged up next to oil in the engine compartment.

OK, I'm poking fun at this notion but really it never occurred to me before to worry about the Li battery storage, just the charging period.

 

[ERD50]

I took a look at those youtube titles. People fired bullets at Li batteries, poked them with knives, hit them with a hammer, short circuited them, overcharged them, etc. Nothing I'm planning to do but maybe if I'm bored I'll shoot one with a 38.

I don't think the storage at garage temperatures is a big safety concern, it's the charging (can possibly be dangerous at any temperature). But storage at high temperatures will degrade the pack.

-ERD50

 

[Lsbcal]

I don't think the storage at garage temperatures is a big safety concern, it's the charging (can possibly be dangerous at any temperature). But storage at high temperatures will degrade the pack.

-ERD50

I looked the article you linked above very briefly. They did show a permanent capacity loss for high temperate storage for 1 year.

Of course, the homeowner uses the batteries during the year and also the temperature might reach 100 F for only a fraction of a year. So my guess is that this is not a worry for gardening equipment batteries. If one was doing this to a laptop or smartphone with non-removable batteries, that would be more of a concern.

 

[Telly]

Thanks for the info and comments.

When I posted, I had been thinking that batteries and heat often don't go well together. But I liked keeping the battery on the extendable trimmer for convenience, and not knowing where else to put it.

It would seem that if the number of cycles is reduced and/or useful run time decreases over time, I would be OK with that considering how rare I would use it, and not running it long when I do. However... the best price I have seen on the battery itself is $76.

I guess I worry about some heat-related issue that would render it useless instead. So I went and pulled it off the trimmer and brought it in... didn't want to keep thinking about how hot the garage is. So it probably would be OK leaving it out there, but I don't need more things to worry about!

It's interesting to hear that I'm not the only one who charges batteries on non-flammable surfaces only! Even my cellphone, with it's little battery sits on a countertop, not dumped in amongst papers while charging.

Good info on depth of discharge. I remember reading years ago that the Prius and Ford Escape Hybrid Ni MH traction batteries were only used down to 50% capacity for battery longevity.