FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Discussion Forum

Discussion Forum

time charge your batteries

ponytl | Posted in Tools for Home Building on August 22, 2008 02:23am

I know i have well over 20 dead 18v dewalt batteries….  and yeah i’ve left em on charge for days on end parked in the charger… (thats close to 2k in batteries)

so i have this really cheap 18V impact driver from harbor freight…. BTW it works really well for drive’n 3.5″ screws.. it’s a beast and for under $30 not a bad deal… I bought one for my dad and whats he do? reads the directions… something  I avoid… a guy thing I guess… but he tells me it says to never charge the battery for more than 7hrs..

I picked up one of those $5  turn you lamps on & off while you are away timers…  I have an 6 outlet strip plugged into it… and my “bank of chargers” paslode, dewalt x2 , harbor freight…  and i set it for 7 hrs…  will this help in the life of my batteries? I don’t know… but I do know sometimes the batteries would be pretty warm on the charger so I don’t see as how it can hurt for $5 if i add just a little life to them I’m good… Plus i assume there is always a little fire danger leave’n them on charge

p

 

Reply
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Replies

  1. DanH | Aug 22, 2008 02:33pm | #1

    Gee, I thought everyone knew that you shouldn't leave batteries on charge for extended periods (unless you have a "super-smart" charger).

    We use a timer on our cordless lawnmower charger over winter. Set it to come on for about an hour a day.

    Would be nice if someone would come up with a plug strip with built-in timer. Press a button and the strip comes on for a programmable 2-8 hours, then it goes off and comes on again for an hour or so every day or two.

    Too much sanity may be madness. And maddest of all, to see life as it is and not as it should be! --Miguel de Cervantes
    1. KenHill3 | Aug 22, 2008 04:25pm | #2

      Yeah, I also have a pile of dead 18v DW batteries- I get p!ssed off every time I see 'em.

    2. Sasquatch | Aug 23, 2008 12:45am | #6

      When you buy a cordless tool, why should you have to become a charging expert?  I understand the realities that require some learning, but frankly, most of the learning doesn't work.

      This is 2008, people!!!

      I think I should be able to charge a battery when it gets low.  If I leave it on the charger, I should not have to worry about what types of electronics are involved and whether they are up-to-date.  Frankly, I think the specifics of the latest electronics are meaningless to users anyway.  I should not have to worry about setting my house on fire because I am charging a battery, as almost happened with a DeWalt battery-charger combo I bought, and which had the new electronics.  I got home just as the smell from the melting plastic was getting into the house, and probably not too long before the battery was about to catch fire.  It had already melted into a glob over the charger so that they could not be separated.

      Zenith went out of business partly because their TV sets had a nasty habit of burning down homes.

      Think about all the electronics in your home, the gas appliances, and whatever else you have.  What if you had to shut off every one of them when you go to work?

      Chargers are  simple.  They have one function.  They should be reliable.  If a charger ever burns down my house, I will be a multimillionaire!

      1. geoffhazel | Aug 23, 2008 12:52am | #7

        I've always left the spare battery on the charger until I need it for the one I use at home.

        For the ones I take in the field, I wind up charging the spare frequently as they don't seem to hold a charge too long when not in use.  This is the Ridgid 18V Li-ion battery.

        They charge up in an hour, and.... best of all.. have a LIFETIME guarantee.  And I'm planning on handing them down to my kids... lifetime = until someone loses it.

      2. DanH | Aug 23, 2008 12:54am | #8

        I agree that you SHOULDN'T have to worry about leaving a battery on charge too long. But what SHOULD BE and what IS are two different things. (Just ask any Microsoft user.)
        Too much sanity may be madness. And maddest of all, to see life as it is and not as it should be! --Miguel de Cervantes

  2. Piffin | Aug 22, 2008 06:09pm | #3

    First item - The dewalt batteries and chargers are one of the weak points in their power systems and tools - subject to more complaints and recalls than any other brand. recalls primarily because of chance of fire caused by overheating.

    I never like to leave my batteries on the charger when nobody is there. It is a possibility for any brand. My main reason though is that we get a lot of power surges out here because of the climate going through menopause. I had a couple chargers and batteries ruined by leaving them plugged in and on over a weekend with lot of storms. So I learned.

    That said, the 'better' tool companies have the modern chargers designed so that they sense when the battery is fully charged and cut the fill load down to a bare trickle - knowing whether yours do or not comes down to reading the manual that cam with - or looking it up on line.

    i', betting the cheapo tool has a charger with the older technology lacking the chip to control the flow of juice - thus the reason for unplugging it after 7 hrs

     

     

    Welcome to the
    Taunton University of
    Knowledge FHB Campus at Breaktime.
     where ...
    Excellence is its own reward!

    1. DanH | Aug 22, 2008 07:34pm | #5

      Most chargers will slow down to a trickle once the battery is charged, but even that trickle can "cook" a battery over a period of days or weeks. The smarter chargers turn the charge completely off, then cycle it on briefly every few days.
      Too much sanity may be madness. And maddest of all, to see life as it is and not as it should be! --Miguel de Cervantes

  3. junkhound | Aug 22, 2008 06:48pm | #4

    The DW chargers are smart enought ot turn off battery charge when at full charge for a good battery.  If one cell has gone bad, the charger is not smart enough to turn off so trashes the rest of the cells also. Checking the pack voltage after a 15 in charge (with one of the $2.67 HF meters<G>) will show if the pack is OK or not.

    The HF chargers will trash any battery leaving it on a battery for only a few days if you power co. line voltage is over about 118V. (most are 120)

    Even with a good charger, what will trash a battery is going to full depth of discharge when you run  the drills. Cycle life is very dependent on depth of discharge, the battery on a drill should be put back on charge immediately when you notice the drill slowing down.

    I cut the leads off my HF battery charger plug in station and soldered them into the internal terminals on the DW charger which works fine.

    Also, the HF 18 V battery pack internals can easily be packed into the DW pack.  <$10 replacement, and takes only 5 minutes or so if you do 4 or 5 at a time after do a couple and learn how. The HF packs have cells from 2 different chinese vendors, one type is 1.2A-Hrs, the other 1.8 A-hrs, you can tell the better one in a HF store by simple comparison of weight - the 1.8 is heavier.

     

     

     

  4. User avater
    Gunner | Aug 23, 2008 12:55am | #9

        When the battery is dead.(and only when the battery is dead) put it in the charger. When the battery is fully charged take it out. Simple little formula I have used succesfully since my first cordless tool. . And if you don't have enough time to get a full charge before you go home, leave it for the next day. No math. No thinking.

       I can't believe you don't know these things. I swear if you start a new thread with a great revelation that toilet paper can be used to get the brown stuff off your butt I'm gonna come down there and smack ya. :)

     

     

      I mean. Who's dumb enough to bugle an Elk in a zoo?

    http://somafm.com/listen/



    Edited 8/22/2008 5:56 pm ET by Gunner

    1. User avater
      basswood | Aug 23, 2008 01:17am | #10

      Uuuhm, I think I know the answer to your tagline question. Do I win a prize?

      1. User avater
        Gunner | Aug 23, 2008 01:24am | #11

           Your partial to the witness.

         

         

          I mean. Who's dumb enough to bugle an Elk in a zoo?

        http://somafm.com/listen/

        1. User avater
          basswood | Aug 23, 2008 01:30am | #12

          Jeeze, I can't win for losin' !

    2. Sasquatch | Aug 23, 2008 01:44am | #13

      I have tried that theory, among others.  It is not reliable.  I was taught that method with NiCad military radio batteries in the late sixties, and several times since then.

      It did not work then and it does not work now, hence all the other methods of getting the maximum life out of batteries.

      I have an 18V DeWalt on the desk next to me right now that was handled that way.  It is dead as a doornail, and prematurely at that.  I do not use the term "dead prematurely" based on any manufacturer-supplied information.  I use my experience.  I have seen batteries in many applications last as long as they were advertised and even longer, as compared to similar batteries used in the same way.  My best DeWalt 18V battery was bought reconditioned on E-bay in 2003.  It outperforms my remaining three DeWalt batteries, which were all bought new since then.  Also, three of the ones I bought since then also had to be recycled because they were dead prematurely and the fourth was the melted battery I mentioned earlier.

      My conclusion is that the manufacturing of batteries does not have enough consistency, probably mostly in the ingredients, that is necessary to make reliable batteries with reliable lifetimes under circumstances where the user follows instructions.  In other words, I believe that the manufacturers make some good batteries and a lot of mediocre batteries.  Batteries are expensive for us and for them.  They are also a great profit center.

      It's the same with saw blades.  When you get a good one, you know it.  You use it as long as you can and then go to get the same model.  That is where you find out you have been fooled (euphemism), or the replacement blade is just as good and you know you are dealing with a company that cares about its reputation.

    3. junkhound | Aug 23, 2008 02:08am | #14

      and only when the battery is dead

      If by dead you mean it wont even spin the motor at 1/2 speed with no load, .....?

      then you are SHORTENING the life of the battery significantly!

      1. User avater
        Gunner | Aug 23, 2008 03:27am | #16

           I've had pretty good succes with this program.

         

         

          I mean. Who's dumb enough to bugle an Elk in a zoo?

        http://somafm.com/listen/

    4. ponytl | Aug 23, 2008 02:09am | #15

      i've had melted DW batteries that self destroyed after be'n on charge for less than 2hrs... i have a 10yo 14.4v that i pulled out of the garage (was sit'n there for 5yrs) and it still works fine  both batteries... i've never taken any type of care of the batteries... i have a bank of chargers and i put all the batteries on charge at the end of the day... some of my paslode batteries are well over 5yr old... could be older since all my paslode stuff is pawnshop finds...

      I tried float charging my RV motorcycle and boat batteries and i get a few years out of them....

      I assume that my dewalt chargers are "smart"   but... I'm guess'n that the 7 hr timer won't hurt anything...  i know this soulds weird BUT i have a little 12v to 120 v thing that plugs in the cig lighter(noe refered to as a power port) in my subaru (it's in the far back corner)  it only powers up when the motor is running... i keep a charger pluged into it and a battery in the charger... i keep a drill and dw flashlight in the subaru (for when i play maint. man)... BUT these batteries seem to last longer than the ones i keep on my jobsite...

      now i don't know where you get your paper products but if you buy brown paper from the start... I think you'll get longer life and more use out of it... oh yeah always wear black underwear... then when u get hit by that car no one will know if it's clean or not....

      yep it's all fun and games til someone loses an eye.... then it's just fun and games they can't see any more...

      p

      Edited 8/22/2008 7:46 pm ET by ponytl

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Video Shorts

Categories

  • Business
  • Code Questions
  • Construction Techniques
  • Energy, Heating & Insulation
  • General Discussion
  • Help/Work Wanted
  • Photo Gallery
  • Reader Classified
  • Tools for Home Building

Discussion Forum

Recent Posts and Replies

  • |
  • |
  • |
  • |
  • |
  • |
View More Create Post

Up Next

Video Shorts

Featured Story

FHB Summit 2025 — Design, Build, Business

Join some of the most experienced and recognized building professionals for two days of presentations, panel discussions, networking, and more.

Featured Video

A Modern California Home Wrapped in Rockwool Insulation for Energy Efficiency and Fire Resistance

The designer and builder of the 2018 Fine Homebuilding House detail why they chose mineral-wool batts and high-density boards for all of their insulation needs.

Related Stories

  • Old Boots Learn New Tricks
  • Install Denim Insulation Like a Pro
  • Podcast Episode 691: Replacing Vinyl Siding, Sloping Concrete, and Flat vs. Pitched Roofs
  • FHB Podcast Segment: Roofing on Commercial vs. Residential Buildings

Highlights

Fine Homebuilding All Access
Fine Homebuilding Podcast
Tool Tech
Plus, get an extra 20% off with code GIFT20

"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Fine Homebuilding Magazine

  • Issue 332 - July 2025
    • Custom Built-ins With Job-Site Tools
    • Fight House Fires Through Design
    • Making the Move to Multifamily
  • Issue 331 - June 2025
    • A More Resilient Roof
    • Tool Test: You Need a Drywall Sander
    • Ducted vs. Ductless Heat Pumps
  • Issue 330 - April/May 2025
    • Deck Details for Durability
    • FAQs on HPWHs
    • 10 Tips for a Long-Lasting Paint Job
  • Issue 329 - Feb/Mar 2025
    • Smart Foundation for a Small Addition
    • A Kominka Comes West
    • Making Small Kitchens Work
  • Issue 328 - Dec/Jan 2025
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 70%

Subscribe

Enjoy unlimited access to Fine Homebuilding. Join Now

Already a member? Log in

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data