Battery-powered Tools

I have a B&D weed whacker that sits out in all sort of weather with the battery pack on it for months. I only plug in the battery pack when it drains down. The WW works fabulous even though it sits out all the time.
On the other hand the battery for my Sony camera regularly loses charge even when the camera is not in use so should that battery stay charging until I need it? Just some thoughts for decision making.

 

If the battery pack is Lithium-ion, it is not prone to memory effect and its life time should be longer if you keep the battery at 40% of its total charge and avoid heat. Laptop Li-ion batteries tend to have a defined lifetime, whatever you do with it (keeping it always on charging, making many/little recharges, etc.); I cannot confirm if tool batteries are alike.

For NiCad and NiMH, my experience is that they slowly discharge over time. Their life goes with the number of recharges. I would therefore let them drain when not used and charge them only when needed.

You then have to plan ahead when you need to use the tool...

Also, it depends on the type of charger used. Some are pretty dump and simply apply a fixed voltage to the batteries and you are required to unplug them after sometime to prevent the battery from getting very hot, hurting its lifetime. Others are smarter and will not do much damage.

 

It really depends on the specifics. Leaving the batteries sitting on a shelf, not charging shouldn't, generally speaking, hurt them. Most chargers for the past 10 years are "smart" enough to realize when a battery is full and slow down/stop charging it (otherwise the battery would explode), which reduces the electrical drain... but every device you have plugged in draws power, regardless if it's on or not.

 

On the other hand, storing NiCad and NiMh batteries completely discharged can cause them to refuse to charge. It's a double edged sword. NiCads need to be cycled, or they develop "memory" and lose capacity, so run them down before recharge. NiMh are resistant to this. For both NiMh and NiCads, I would charge them before use if they have been stored for a long time, and charge them every few months if they are not being used.

Lead acid batteries, like those found in some garden tools, like to stay charged. Deep cycling lead acid batteries kills them quickly.

Tom

 

I think charged up and unattached to the drill is the best. It won't self discharge as quickly. Leaving it in the charger might lead to burning out the battery.

 

Well, not every device. Just like connecting a water hose to your faucet won't use water, products with real "Off" switches in the Primary Power Circuit like a simple table lamp don't actually use power just because they are plugged in. If the products have an unswitched circuit like a touch lamp control or a transformer in them where the power is only switched in the secondary circuit, then you start getting power leakage. Almost anything with a big "wall wart" plug and most products with remote controls have unswitched primary circuits waisting a little power all the time, and the problem is that there are so many of these, it is like having slow leaking faucets all over your house. A good solution is to connect all these products into switched power strips that you turn on when you will use them.

Example, your TV, Cable or Satellite box, DVD player, Sterio all have their own unswitched transformers to power a remote control monitoring circuit. Connect all these devices to a switched power strip and turn it off when you are not using the entertainment system. As a bonus, you can plug in your power tool charger to the same power strip, and it will only top off your batteries when you watch TV instead leaking electricity 24/7.

 

I would charge up the battery first, then unplug the charger and store them. Like someone else mentioned, I too have the B&D weed wacker, and also drill (they use the same battery), and they can sit all winter with no ill effects. Good Luck!

 

I've got a black & decker yard set (weed wacker, leaf blower and hedge trimmer) and a black & decker cordless electric (battery powered) lawn mower. I have the lawn mower charger and the 3-battery charger for the yard set plugged into a y-cord then to a kill-a-watt meter. Over the summer it's been so hot nothing is growing so I only occasionally use the weed wacker for edging, otherwise nothing else is used much through summer and winter. I typically plug the kill-a-watt in with the chargers at least 24 hours once every two weeks or so to top off the batteries and if I use something I'll plug them all in again for at least 24 hours.

After mowing the entire front and back yards and doing all the edging using up all 3 batteries it usually takes nearly 1 KWH to charge everything after being plugged in for about 24-48 hours.

 

Electrically, this statement doesn't make sense. KW is a measure of power, not energy. Perhaps you mean KWH, which is one KW for one hour. Generally electrical energy is sold by the KWH.

Tom

 

I was speaking in generalities... Something simple link a lamp doesn't draw power when it's off, but nearly every electrical device - from the computer to the TV to the microwave to a simple radio - is going to draw some power when off. Almost everything with a transformer in it (which is almost all of our electrical devices, as DC current is much more useful than AC) will draw power unless the switch is before the transformer, which is pretty rare.

 

I would change this statement to say "...(which is almost all of our electronic devices...)...". Most electronic devices have power supplies, while many (most) electrical devices are line powered. It's a small point and in no way diminishes the authors message.

Tom

 

Consider it a typo on my part

 

I was thinking about the original question regarding saving energy for a battery powered power tool when you leave the charger plugged in all the time to keep the battery topped off, and I thought one idea would be to connect the charger to a lighting circuit that you have on a couple hours a day. Then, each day when you turn on the light for a couple hours, the battery will get topped off, and the other 22 hours per day, the charger will be off.

 

Might as well put a timer on the outlet, no electrical wiring necessary and it'll be automated.