How to Care for Rechargeable Cordless Tool Batteries

Cordless rechargeable drill with battery and charger

Rechargeable cordless tools are convenient, portable, and ready to work at a moment’s notice. Cordless tool batteries last for several years; and with proper care and storage, you can extend battery life and your investment.

Here are some dos and don’ts to help you get the most out of the batteries on cordless tools.

Rechargeable Tool Battery Dos

    Cordless rechargeable tool battery charger
    Charge and store batteries correctly.
  • Do Keep Battery Charged: Recharge cordless tool batteries as soon as you notice a decrease in power. Most batteries last longest if recharged when they reach 70% capacity. Even NiCd batteries (the ones with the so-called “memory effect”) only need to be completely discharged every month or so to retain their charge memory.
  • Do Use Battery Regularly: Battery life decreases with lack of use, so keep those tools in action! If you only very rarely use a tool, you may want to consider a plug-in version, or plan to recharge the cordless tool battery before starting a project.
  • Do Charge Battery Completely: Be sure to leave the cordless tool battery plugged in until it’s completely charged. Most chargers have an indicator to let you know when the battery is fully charged.
  • Do Keep Battery Cool and Dry: Cordless tool batteries will last longer if stored in a dry, climate controlled dry area. It’s not necessary, however, to store batteries in the freezer.
  • Cordless rechargeable battery powered drill chuck with torque settings
    Adjust torque setting on drills.
  • Do Store Battery Properly: Store your cordless tool battery in the original carrying case, or in a cushioned bag. Be sure to use the plastic cap that came with your battery to keep it from short circuiting and to protect the terminals from breakage or moisture.
  • Do Have a Backup Battery Handy: It’s a good idea to have a second battery available and charged for your cordless tool, so you can switch out in mid-job.
  • Do Protect the Battery: Be gentle with cordless tool batteries – they won’t work if damaged or cracked.
  • Do Adjust Cordless Tool Settings: Be sure to use the right tool setting for the job. For example, higher torque settings can run down a cordless drill battery faster, so you’ll get more battery life if you use the setting that’s needed.

Rechargeable cordless drills and string trimmer

Rechargeable Tool Battery Don’ts

  • Don’t Run Battery All the Way Down: Deep draining (letting a rechargeable battery run all the way down), can permanently damage the poles and shorten battery life. Instead, recharge the battery as soon as your tool starts to slow down. Never deep drain unless you have a NiCd battery that’s showing decreased capacity due to the memory effect.
  • Cordless rechargeable string timmer
    Keep battery from overheating.
  • Don’t Leave Battery on Charger: Unless your tool instructions specifically say to store the battery on the charger, be sure to remove it after charging is complete. Overcharging can damage a battery and shorten its life, and not all chargers shut off automatically.
  • Don’t Overheat Battery: Heat is deadly to rechargeable batteries and can even cause them to explode. If the battery gets hot to the touch, let it cool down before recharging or using. Don’t store rechargeable batteries in a hot car, attic, or overheated storage area.
  • Don’t Get Battery Wet: Don’t expose your cordless (or corded) tools or batteries to water. Immediately wipe away any moisture on the tool or battery.

Further Information


  1. Your web site instructions say to unplug rechargeable batteries when they are fully charged. However my charger (Ryobi) says that the charger will shut off and not continue to charge when the indicator light says “charged” Can we keep them in the charger or remove them when charged.

  2. “Not necessary to store the batteries in the freezer” – do you know NOTHING about batteries? If you try that – you will only be replacing the battery. FROM EXPERIENCE. I had 3 Makita batteries that after reading a “knowledgeable” website instructed placing them in the freezer. $300 bux later I had new batteries. They would not even take a charge again after spending the night in a freezer. I would REMOVE that comment so you would not mislead anyone into thinking its a wise thing to do – before someone wastes their money from reading something online.

    • Hi Analyzes,
      You must have misunderstood our article, it said it is “NOT necessary to store rechargeable batteries in the freezer.”

  3. You say that the NiCD batteries have a “memory effect”. My understanding (several other articles) is that is NOT the case.

    Are you certain?

  4. I just want to thank you for the info. I did not know if I was suppose to remove the batteries when fully charged or leave them in. I have a tool that requires the small battery to remain in the tool, which is also the recharger. I saw that because I like to READ instructions. (Women are like that…) Thanks for the info, and I now know to remove my battery from the charger when flashing blue..and also not to completely drain the battery! Guilty of that! I also have something to share with my husband…that I now know.. (ha)
    I would rather have my good tools , that my husband has bought me through the years.. than a diamond ring. WHAT GOOD ARE THEY> ha…(One of a kind but feminine..)

    • If there’s no continuous power juicing up the tool, it should be fine to leave the batteries inside the tool with the power turned off.
      However, for optimal performance, it’s always best to ask the tool’s and battery’s manufacturer.

  5. No, a NEW lithium ion battery should not come with NO power, in a state where it will not take a charge. Lithium batteries that have been OVERLY discharged, usually while under a heavy current load will trip the battery’s protection circuit or if left discharged for an extended period, it creates a situation where the chemistry of the battery has changed due to inactivety. The battery can most likely be revived. However, lithium batteries will explode if not properly “brought back to life” or even charged incorrectly. Don’t mess with it. Return the battery for a replacement.

    • We recommend storing batteries outside of a charger or drill when they’re not in use.
      However, for optimal performance, always check with the battery manufacturer, as directions may vary.
      Thanks for your question!

    • I’ve had a Ryobi cordless drill with a lithium-ion battery for several years now. I keep the battery in it when it’s not in use and haven’t had any problems with it running down. I read several cordless drill manuals, and they didn’t mention taking it out when not in use. On drills with a non-removable battery you can’t take the battery out. My take is you can take it out if you like, but it doesn’t seem to hurt to leave it in. Hope that helps!

  6. I have a DeWalt drill that has the battery in the handle. However, the strength is minimal in my 80 year old hands to squeeze the releases on the side. Do you have any tips for removing the battery, i.e. a tool that will do this easily?

    • Hi Joan,
      You might could find a clamp, such as a “C” clamp or wooden handscrew, that would fit around the drill and press on the release clips. Just don’t tighten it up too tight, since it might damage the drill battery.

  7. I have an older Makita drill model 6095D which uses the 9.6 volt Ni-CD battery. It has worked great for many years. However, just recently the charger on all three batteries I have will not charge fully. I have traced it to the charger reaching a thermal limit and turning off because if I put the charger in the refrigerator while charging it will go to the end of the charge time and also in the winter ( I store the tools in the garage) the charger will charge much better. Have you seen this to be a problem?

  8. Regarding problems with dewalt 18v nicad batterys and charger ..i got the drill second hand as a replacement for mine being stolen on my friends job …came with one older battery and two new ones still boxed. Had only been using them for two months when one morning put one on to charge, ok to start then a minute later got the fast flashing indicating a useless battery …ok this also happened with the other two. So three batterys at the same time …checked batterys with multi meter, they all showed they were still good …must be the charger …i opened the charger up. Then saw a board with fuses and all sorts, didnt have a clue. On closer inspection i noticed the prongs that the pins on the battery fit into seemed to be wider than the pins. I decided to use my long nose pliers and squeeze the prongs closer together. Closed the charger up, plugged it in, put battery in and problem solved. Sll three batterys then took a full charge to my relief… My point is i almost decided to bin the lot and would have wasted a good drill and batterys because of a simple problem. The fact that i couldn’t afford to buy a new one and my determination that the batterys were ok made me check the charger. How many people have binned drills and bought new one when it could have been as simple as this?

    • Hi, Jimmy,
      We don’t offer information on product availability, as this varies by location, but we encourage checking your local phone listings for nearby home and appliance centers.
      Good luck!

  9. How to store a Lithium-ion battery for a long time. I have this wonderful GSB-18v Bosch drill 4Am battery, the problem is that I may travel for a long time so I’m wondering how to save these batteries from self-damaging??

  10. I have 4 black & decker 18V batteries. What is the best way to store these batteries for the winter. They are not used during that time for about 6 months?
    Thank You,
    Al King, Michigan

  11. I have 4 black & decker 20V batteries, 14.4 v batts, and Makita 18v batts.. What is the best way to store these batteries for the winter. They are not used during that time for about 6 months?
    Thank You,

  12. I have two 18 volt ni-cad batteries for my graco sprayer. They show 20 volts each when tested, and when placed in the charger, the charge glows steady green for full charge. Yet, when I try them in the tool, I get nothing. I have another battery of similar type that operates the tool when installed.
    I have wiggled the contacts with the battery installed, and got nothing also.
    Any thoughts?

    • Hi, Skip,
      As always, we recommend contacting the manufacturer for product-specific questions.
      Here’s where you can do that:
      Good luck!

  13. I have just bought a Bosch Cordless Mower and wonder how to care for the battery.
    Should I recharge after use ?
    Should I leave on charge ?
    What do I do during the winter ?
    Can anyone advise me ?

    • Hi, Wilson. That depends on the battery’s manufacturer. Some chargers (such as those from Ryobi, for instance) have clear indicators of charging levels; others have vague indicators.

  14. If the batteries for my Black & Decker weed wacker are fully charged and I don’t use them right away because it rains will they loose some of the charge ?

    • Hi, Beverly,
      It’s likely that they will, depending on the length of time between the initial charge and their actual use.
      In fact, we recently heard from a homeowner who didn’t use his Black and Decker trimmer’s batteries for an entire season, and the batteries completely drained.
      As always, it’s best to contact the battery’s manufacturer for tips to ensure optimal performance.
      Good luck!

  15. I have a 40v rechargeable battery. When I install the battery on the charger the green lights start flashing. Thinking the battery is charged I put it on the piece of equipment that I was trying to start. Nothing happens.

  16. I have a Black & Decker 40v trimmer, I charged it up completely at the end of the trimming season Nov. 2017. I’m needing to start trimming this season Apr. 2018, but the battery completely drained and I’m having to recharge it before I can use it. This should not happen, I have a Green Works blower and the battery for it stayed charge, shame on Black & Decker for their bad batteries, I will never buy a Black & Decker ever again.

  17. I have several of the Ryobi cordless tools now. I cannot find any specific info on what temperature range (coldest) they can be stored at. I live in a cold climate and would like to store them in an outdoor building instead of in the house.

  18. New rechargeable batteries apart from the LSD variants come in a discharged state and it might take 3-5 cycles to get to the rated capacity of the battery, also do note that batteries which have not been used for a while might require re-conditioning of the batteries to get their rated capacity.

  19. A little info. I have A ryob I 18v lithium. Found out it i depleated my battery too much, it would not charge. Ryobi sent me a new charger. Works fine now

  20. I have 3 gmc batteries I charge the 3 but a couple of days later when I want to use them I have to charge them again can use on the day but after that they go flat wont hold charge for longer than 2 to 3 days

    • Hi, Mike,
      We would recommend contacting GMC to see what’s happening there.
      While it sounds like the batteries are running out of power fast, it depends on their age and how you’re using them, along with other factors.
      Good luck!

  21. My craftsman weed eater battery got wet, will not charge, it says, technical issue refer to manual, I no longer have the manual, please help

  22. Ok, here’s my question that will annoy many, ahahah… I bought a rechargeable hand drill 3 years back and never opened the box (<< that's the annoying bit ; ) … Can I expect it to function well at this point? I guess my question refers to it's shelf life. Of course I can pull it out eventually and run it, but thought I'd ask. Thank you : )

    • Hi, Linda!
      We can’t see why the rechargeable drill wouldn’t function well, especially if the box has never been opened and it’s never been used.
      However, the biggest concern with waiting too long to open a power tool is that it may be past its manufacturer’s warranty.
      So, for instance, if problems do arise, you won’t be able to easily replace it at no or low cost.
      Go ahead and open that drill, give it a whirl and let us know how it goes. 🙂

  23. Interesting in formation on how to use and maintain rechargeable batteries but my question was not answered.

    The problem I have is that, having fully recharged my cordless drill li-ion 12 volt batteries, when installing them
    back in the tool and pressing the trigger, the drill runs for a moment and than stops and if I try again a moment
    later, the same thin g happens again….
    Does it mean the batteries are finished, or is it a problem with the tool itself?
    Are there on the market load testers similar to those for automobile batteries testers that won’t cost an arm and a leg ?
    Thank you

    • Hi, Jacobo,
      Great question! We have forwarded it to the Today’s Homeowner Radio Show’s producer.
      He will contact you soon to discuss featuring it during an upcoming show.
      Take care!

    • Hi, Carl,
      You didn’t mention the age of each battery, and how much use each one gets, so this could be due to any number of reasons.
      We’re opening this question to the community.
      Have any of y’all experienced the same thing?


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