Maintaining 'infrequent use' power tool batteries?

[Toxic_Avenger]

Does anyone have any tips for maintaining lithium ion power tool batteries that don't get used every day?
I like the convenience of cordless tools, but they are more expensive than their corded companions. I'm not keen on having something that is useless once the manufacturer stops selling / supplying batteries. Basically, looking for ways to maintain the tool 'investment' as long as I can.

So what's the best way to go? Run the batteries until flat once every 6 months or so, then fully re-charge them and store them?
Keep them fully charged and don't worry about it?
Or store them flat (although I'm pretty sure that's how they die!)
Or something else entirely?

[Slunnie]

Keep them charged and don't run them flat.

Actually, our newer ones will turn the machine off before the batteries get too low.

[Homestar]

Was told to keep the lithium batteries on my drones over 80% when not using them, so yes, looks like keeping them fully charged is the way to go.

[Aaron IIA]

From what I have read, to get the longest life from lithium based batteries, they should be stored at about a 80% charged state.

Aaron

[d2dave]

Lithium batteries have a very long shelf life compared to others, so if you have them charged they should be ok to sit around for 6 months.

Obviously if they are charged to 80%, which by the way is the best way to store them, the shelf life will obviously be shorter.

So your options are, charge to 80% and check more often or charge to 100% and check less.

And at the other end of the scale, for maximum life you should recharge at 50%.

[Hay Ewe]

I had similar thoughts when I needed to buy a new electric drill, I went with a mains corded type because I wont use it enough and don't have to worry about the batteries decaying and not being able to get replacement

Sure, the convenience is not there, but I have a long extension cable!

[Saitch]

One battery mob (Battery University) state for Li On batteries that they should be stored at 40% SOC & 15 deg C. A mate has quite a few batteries & has a little fridge in his w/shop for storage. Too warm for beverages though
Steve

[EastFreo]

I am with Hay Ewe. In recent times I have gone back to the cord and mains tools. Too many battery ones lost their charge. Admittedly none were at the top end. But I am only needing them every now and then.

[MR LR]

Buy a big name brand like Makita or Milwaukee, then your batteries are good quality, fit a hugeeeeeee range of skins, and you'll only need to buy two to run as many tools as you want.

On one of our sites we don't have any power, only thing we use a generator for is the drop saw and welder, the rest is Makita Li-Ion powered!

Leave the batteries on the charger when not in use, it will maintain them. Unless you are one of those freaks that think powering an LED will cost them their first born...

[Toxic_Avenger]

I had a chat today with a work colleague who previously worked for a big red Liechtenstein-based tool company.
Apparently there are only a handful of battery manufacturers who supply the power tool market, as none (other than panasonic) have vertically integrated into battery manufacturing. Most configurations of the 18604(IIRC) lithium cells, which are crammed into the various form factors of the battery packs.

Most of the time, the milwaukee's and the makitas of the world will go to such a manufacturer with a requirement for X batteries at Y voltage, for a range of tools that have Z Amp draw to come up with a battery solution for a reasonable run time at an acceptable cost. Much of the quality / obsolescence comes from the 'flavour' of battery the manufacturer chooses, economies of scale / buying power etc, rather than one manufacturer's battery being 'better' than another's.

So a little bit of food for thought on how it works in the tool factories.

There has been plenty of good advice on how to maintain / store the batteries, keep up the good info if there is any still out there!