Should cordless power tools be stored without batteries attached?

[drbobj]

Thanks as always for your videos, As you requested in the video (yes I was paying attention) I am posting my comments here. I do have the three tools you mentioned however my shop vac is corded, it also collects dust on inside but since I don't use it much also collects dust on outside. I did have a question/comment. I noticed as you showed each of your battery powered devices they initially did not have the battery inserted but on the impact driver you did insert the battery to demonstrate it's use. My question is do your store your devices with battery not attached. Is there any benefit to doing that or was it just coincidence? BTW I am in San Diego, CA USA. So my cordless impact driver and drill are DeWalt. Next time I need to loosen stuck fastener on bike plan to use impact driver, as long I have correct bit.

 

[BikeGremlin]

Thanks as always for your videos, As you requested in the video (yes I was paying attention) I am posting my comments here. I do have the three tools you mentioned however my shop vac is corded, it also collects dust on inside but since I don't use it much also collects dust on outside. I did have a question/comment. I noticed as you showed each of your battery powered devices they initially did not have the battery inserted but on the impact driver you did insert the battery to demonstrate it's use. My question is do your store your devices with battery not attached. Is there any benefit to doing that or was it just coincidence? BTW I am in San Diego, CA USA. So my cordless impact driver and drill are DeWalt. Next time I need to loosen stuck fastener on bike plan to use impact driver, as long I have correct bit.

Hi,

That's a good question - and quite observant of you. I'll try to give a short answer, followed by some borderline scenarios, and finishing with a full (and longer) answer (the hows and whys).
Appologies in advance for my long-windedness and imperfect English (I've edited the original thread title to describe what the question is about and help with future search for answers).

For anyone arriving here from Google/search, the post is related to this video:

Short answer​

With most modern, high-quality power tools and batteries, it's generally OK to leave the batteries in the tools (I'd say that both Bosch and DeWalt fall into this category. It is mostly my OCD, and the fact that I try to cycle all my batteries evenly (keep them all charged and discharged regularly, without using one too much/all the time).

Risky scenarios that might warrant keeping the batteries separate​

Some of these are more obvious than the others:

• Children, pets or unskilled grown-ups access risk.
• Extreme cold, heat, or air moisture.
• Prolonged periods (a month or longer), especially with Bluetooth equipped power tools.

Longer answer​

Leaving the batteries in the power tools comes with two basic risks:

1. Injury risk.
2. Battery or tool drain and damage risk.

1. Tool injury risk​

The first one is obvious. In a perfect world, everyone would know how to safely handle power tools. In a less than perfect world, batteries should be in a separate storage from the power tools (not even in the same drawer/toolbox). In the real world, people (including me), sometimes leave the batteries and the tools next to each other, even when they do bother to unplug the batteries from the tools.

It is fair to note that most modern tools have several built-in safety mechanisms. For example, my Bosch 18V battery angle grinder has the switch that requires you to push a small lever up (towards the disk) in order to unlock the acrivating lever (not a classic switch). Let me try to add a photo (it's quite nice in practice):

Many other power tools (by many manufacturers) have some sort of safety mechanisms.

Still, even when you are working with tools, it is usually a good idea to unplug them (from the wall socket with corder, or from the battery with cordless tools) when swapping angle grinder discs, drill bits etc.
Before I switched to an X-lock cordless angle grinder, I would keep the disc loosening tool zip-tied to the end of the cord, forcnig me to unplug it before swapping discs... and preventing me from losing it.

From that perspective, when one is not working with tools, there's even less reason for keeping them plugged into a power source - you don't get extra speed or much convenience, but just increase the risk of things going wrong.
Yes, I know it can be practical to keep stuff plugged in - I'm first to admit that my Bosch Pro 12V battery lamp is practically always left with a battery in, but I do try to keep the stuff that can cause injury or harm unplugged when not in use.

The not-in-use part leads to the second risk:

2. Battery discharge/drainage​

Old Ni-Cd (and Ni-MH) batteries were quire prone to self-discharge over time. Modern Li-ion batteries are a lot more stable in those terms. Keeping them plugged into a tool does not result with a lot faster self-discharge, generally. With a couple of caveats to note:

2.1. Bluetooth - bloody bluetooth​

Modern Power tools with Bluetooth connectivity (more and more popular) do drain more battery when not in use - generally speaking.
Some Bosch tools let you install a Bluetooth module, but others, like my Bosch GBH 187-LI, come with bluetooth installed from the factory (not removable unless you disassemble the tool and cut it out).

2.2. Tool and battery imperfections​

Li-ion batteries are very bad when things go wrong (overcharged, too much discharge, current too high etc.). In the worst case scenario, they can start a fire that is difficult to put out. Quite scary.

People make mistakes, and things do break down.

That's another reason why I sleep better when I reduce the risk of anything going wrong.

Keeping it real​

It is fair to note that with any remotely decent tool and battery model, you can safely leave the batteries in. Even with a bluetooth, the worst case scenario is that your battery is drained enough to reduce its capacity permanently (even when recharged). Without a bluetooth, that too is not a risk - and batteries can be left in the tools for months, easily.

I mean, that is exactly what we do with our smartphones, and even with some pro class power tools (Bosch GO Professional is an awesome electric screwdriver that doesn't have a removable battery).

Since my workshop is left unattended when I'm not working (10 minute bicycle ride away from my home), because my tool drawers are not very big, and because I got at least one "bluetooth-always-on" power tool, I think it's a good habit to keep the batteries unplugged, just in case. But it is not a must - especially for tools like that impact wrench (even when swapping bits I'd say).

Relja