Being old fashioned I am hesitant to buy cordless tools. In the other hand I see their advantages.
I do not use my tools that often; woodworking is my hobby, not my occupation. The way I see is that you need to charge batteries just before every use, because few weeks past from last time you utilize them. I did search internet for some review which would address my concern, but to no avail.
Simply I would like to know what is shelf (sleeping) life of a charged battery between uses. It would be appriciated if someone can offer some insight into this.
Replies
Rechargable batteries do lose their charge over time, the older nicads losing something like 1 percent of their charge per day. This means that they will be dead after about three months of sitting around, so the general recommendation is to recharge the batteries at least once every two months.
Rechargable batteries can only be recharged a limited number of times, 100 to 150 times is a number I've seen quoted fairly often. So even if you recharge the batteries once every two months they'll probably last 20 years or so.
I've got a Makita battery pack, on a tool I only use a few times a year,that is still working well after 15 years.
John White, Shop Manager, Fine Woodworking Magazine
Thanks for that advice John. I have a 3-yr. old Hitachi cordless tool set I use constantly, but surgery on my hand in November put me in a non-working mode for 3 months. Guess I'd better drag the batteries out and top off the charge before I lose 'em.
John,
I also have a 12+ year old Makita 12 v. drill. I recently purchased two new batteries and threw one away. Still using the other original but it just does not have the same capacity. Your advice is right on!
A bad day woodworking is better than a good day working -- yes, I'm retired!
Don't throw those batteries away or buy new ones simply because the battery won't hold a charge. I took my 10+ year old DeWalt 18v battery packs to a company called Batteries Plus which has a chain of stores nation wide. They replaced the batteries inside the pack for $54, about half of what a new DeWalt battery pack would cost. And, the batteries were a higher rating than the old ones so the charge lasts longer and has a higher output. The 18v packs work so well, I took in my 7.2v packs for my DeWalt screw driver and got them replaced.
JohnAny comments on leaving the "spare battery" in the charger until it is needed? I leave mine on the charger for months at a time with no problems - so far.Frosty
To help clarify for John (because I'm interested also) -- what type of batter is it? NiCd or NMH??forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
FGMy two pricipal chargers are:DeWalt 14.4 Volt DW9091 batteries in a B & D Univolt XR Pack charger andPanasonic EY503 Electric screwdriver batteries in the supplied charger.In both cases (I just checked) the batteries are cool to the touch after a week or two of charging. I've been doing this for years and battery life is a couple of years. I guess that means that the chargers are good quality and that leaving them there is safe according to JW's reply.FrostyJohn - WHY are you working on a Sunday afternoon? Is this part of a Taunton employment contract?
Just came in to play in the shop and decided to check my e-mail. Taunton's policy is to let me work as much as I want, unfortunately they will only pay for the first 40 hours.
John W.
Good for you, John, on the "play" bit!All work and no play, makes John a dull boy.And you are not a "dull boy"!Frosty
Frosty and All,In my humble opinion (IMHO), two years life is not very good for a rechargeable battery. I can't really say how long mine lasted, but it was beyond that. Others claim very long service lives for theirs. Seems to me that we both should monitor the time in the charger more carefully. My current drill battery charges in less than an hour. That has improved my ability to keep track of charging.What do others say about length of life for their rechargeable batteries?Cadiddlehopper
"In my humble opinion (IMHO), two years life is not very good for a rechargeable battery."--------------------------------------------------------------------I've gotten one year almost to the day out of my Milwaukee NiCds (18 volt), This is from DAILY use, sometimes multiple charges per day. Batteries wear out from use and abuse, and I'll say I'm satisfied with the life I got out of them. Since I retired my older 9.6 drill and used it mainly in the shop and as a loaner the batteries are now 4 years old. they are just now starting to show signs of deterioration. I have not yet killed any LiIon yet (9 months on LXT and about 6 months on V28)
It really depends on how you treat them as to how long they live.Just like a car. Some people can wear them out in a year, some people are still driving a twenty year old.I saw it on the interweb, it must be true.
I've had a DeWalt 14.4 V drill for 11ish years, and it has seen periods of very hard use. It came with 2 NiCad batteries. For the first 6 years the drill was used primarily to assemble swingsets and gazebos which was primarily driving lags and screws. I would often be charging one pack continuously all day, perhaps swapping 4 times - 4 charges each. They have been charged thousands of times at this point. One quit several years ago after being dropped the third time. The other is still ticking although it too has had the case epoxied back together a few times. There is plenty of power, but run times are noticeably less than the old days. I always ran these batteries totally dead (without load) before sticking them on the charger which is supposed to restore the cells in NiCad batteries. I understand that you wouldn't want to do this with LIon, but I don't know for sure. Anyway, in a lot of words, expect your batteries to last a very long time. A drill kept in the workshop, without being dropped or exposed to rain should do better than mine, eh?
Actually you don't want to run them completely dead, you should recharge them when they are obviously starting to fade. That said, some batteries seem to be indestructable, as your experience shows.
John W.
Batteries have a shelf life and a parallel charge/discharge cycle life. You probably exceeded your battery's life by the latter limit. The poster to whom I replied apparently used his batteries far less than you. You may have gotten great value whereas he did not and neither would I. Both he and I should probably be more careful not to overcharge batteries.Cadiddlehopper
Yes, my batteries had a hard life,often overloaded, charged hot, etc. I'm wondering how the new "smart" chargers will work out, with regards to battery life. I know my Makita LXT won't charge until the pack cools sufficiently. I do also know that my old Milwaukee 9.6v charger cooked a battery left on the charger overnight, twice.
While a Dewalt 18v set, that I'm acquainted with lives on the charger when not in use, for weeks at a time, to no ill effect.======================================================================================================
An economy based on the consumption of fixed resources will consume itself.
Hi all, a newbie to this here site, and thought i would add my own 2 cents worth! ( ok Penny's worth, well i am English!) ...
re-chargable batteries, i have used many types, from Makita, bosch, Milkwalkee, but will never stray from my U.S.A. made Dewalt stuff, one of my 12v drills i've had since 1990, still going strong, but actual run time is now getting limited! , i mainly run 18v ni-cads, and according to Dewalts battery techy guys over here they should last a minimum of 1000 charging cycles! but i have found they will last longer than that .. as some of my 18v batts are over 5 years old now, and at the rate i cycle mine through the various 15 minute chargers i have., i can cycle each up to 5 times a day!
yes i am getting less run time from each, but with at least 2-3000 cycles on most of them now i feel i am doing okay!!!
i can using my 15 min chargers leave them over night, and once fully charged they switch to trickle cycle/maintainance charging, which when done about once a month, does seem to add a bit more run time!
regards Matt
I've got 2 18V PC battieries that are still going strong after 3 1/2 years and 2 Makita 9.6 volts that are just limping along that have to be 10+ years old.
Milwaukees new warranty on their 18 & 28 Volt Li-On (Lithium Ion) batteries is 2 year full replacement and 5 year prorated. The SAY to expect to be able to recharge them 2000 times. We'll have too see about that. As far as the Li-On running down to nothing before recharging, thats the way they work. No warning at all, you pick it up and pull the trigger and NOTHING, time for a recharge.
Not to take anything away from FWW ;-), but This Old House Mag has an article this month about cordless tool packages and discusses their battery life.
Depends on the charger.
The simplest chargers don't cut back to a trickle charge, or in some cases completely shut off, when the battery is fully charged. If the charger doesn't go to trickle charge or shut down the battery will overheat which isn't at all good for its longevity.
If the battery is more than barely warm when it sits in the charger for days you are probably better off to remove it.
John W.
http://www.batteryuniversity.com/ will have some info for your research, pay attention to part 2 http://www.batteryuniversity.com/parttwo.htm
Edited 12/30/2006 2:59 pm ET by PutnamEco
Brundo,
I have been using cordless drills for about 20 years on an occasional basis. I found that having two battery sets was a very handy idea. So is a fifteen-minute- or one-hour-charging time. If one goes dead from use, you put it on charge while putting the other to work. Voltage dropoff has not been a problem. Forgetting that the batteries are in the charger has been a problem. I shortened the lives of several batteries that way. Don't invest too heavily in batteries. The switch on my first drill wore out leaving me with two sets of batteries which fit nothing else that was then available.
Keep a corded drill around, too. When I need a real HOLE, I pull out the 1/2-incher with the cord.
Cadiddlehopper
Brundo,
Not a regular in Knots, I usually hang over in Breaktime. Shelf life on NiCad (Nickel Cadmium) is definitely a problem, less so on NiMh (Nickel Metal Hydride). The latest battery is LiOn (Lithium Ion), It is much less of a problem with them. All of the new LiOn systems that I have see (I use the Milwaukee 28V) include an intelligent charger and many of the batteries have charge level indicators on them. These batteries are supposed to stay charged for up to 9 months on the shelf. I haven't tried that myself, but I have left fully charged batteries unused for several weeks with no detectable loss of charge. Also, you can recharge them when partially discharged without fear of having the battery develop a memory as the NiCads will.
As far as power goes, I use my 28V Drill to drive a 4 1/4" hole Saw though siding & sheathing all the time with no problem at all, other than trying not to get my wrist broken. With the 18 - 36 Volt drill drivers that are out there power is NOT a problem. I also have a 28V Sawzall that has completely replaced my wired saw.
Hope this helps, you might want to go over to Breaktime and ask this question, builders and carpenters live and die with cordless tools, you'll get a LOT of feedback.
Edited 1/1/2007 3:19 pm ET by Prof.Morpho
Brundo,
I have several years of experience building, using (and abusing) Nickle Cadmium (NiCd) and Nickle Metal Hydride (NiMh) battery packs. The comments below are based on my personal experiences.
All rechargeable batteries will self-discharge when idle. NiCd cells will lose around 2 to 3 percent of their charge per day fresh off the charger. As the charge level in the cells decreases, so does the self-discharge rate. Good quality, healty NiCd cells will probably lose about 40 to 45 percent of their charge in the first month, and will be effectively "dead" by some time in the third month - sooner if the cells are older or have been abused. NiMh cells are somewhat better, but not a lot - it may take between 3 and 4 months for them to be "dead." The big advantage of NiMh cells is that they can pack more capacity into the same size and weight when compared to NiCd cells - so you can drive more screws or cut more linear feet if your tool uses NiMh cells. My understanding is that LiIon cells have a very low self-discharge rate and can usually be stored for several months with a relatively small drop in their retained charge. I have limited experience with LiIon cells, but what experience I do have supports what I have read. LiIon cells also have a higher power density so that they will be smaller and lighter if they are the same capacity as NiCd or NiMh or, for the same weight, LiIon batteries will have more capacity. Given your stated likely usage, you should either plan to charge your batteries shortly before you intend to use the tool again, or purchase tools with LiIon batteries.
Also, note that all NiCd or NiMh cells are not created equal. Cells built with older technology (read "cheap") will not perform as well as modern, current-design cells. The older types of cells (still manufactured by some sources who do not want to invest to upgrade their manufacturing facilities) will have less capacity and will be more prone to "memeory" and other failings. Unfortunately it is difficult or impossible to obtain information about what cells are used in portable tool battery packs, so we have to trust the tool manufacturer.
Heat is the big killer of NiCd and NiMh cells. Anything you can do to keep from overheating the cells will help to prolong their overall life. For instance, try not to stall the tool with the switch engaged - this will create almost a direct short through the motor and place a *very* high current load on the cells and, as a result, generate a lot of heat (not to mention drain the battery quickly). Also, whenever possible, charge your battery packs in the shade rather than in the direct sun. Using common sense to reduce the heat on the battery cells will help them survive longer. This is probably true of LiIon cells also, but I don't have enough direct experience to be absolutely certain.
Good luck,
Richard Baker
Brundo,
As usual, all of John's advice looks to be right on the money, but I thought I would toss in my two cents...
If you are concerned with shelf life of tool batteries, you might consider jumping on the Li-Ion bandwagon. The manufacturers haven't bothered touting this as a major selling point, but while NiCad and NiMH cells lose about 25% of their charge over a month of dormancy, Li-Ion cells will only lose about 2%.
For more info on these kinds of topics, check out: http://www.batteryuniversity.com
Justin Fink - FHB Editorial
Your Friendly Neighborhood Moderator
This is the answer to the point. No more lingering for me.
Thank you much!!!
Bruno
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