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..)

  5. ever wonder why the makers of cordless powertool bateries ave changed from a in the pistol handle type shape to a it slides in a track on the bottom of the pistol handle?
    could it be makers like bosch or other brands which if one wants to do some digging on their source might find them called by many names perhaps – china electric tool manufacturing co. have found that after a few years use the systems used in the older battery shapes might like mine has done eventually crack and be held in place internally a result being the VERY EXPENSIVE spare battery cannot be put into the handle’s magazine?

  6. 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.

    • 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!

  7. 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.

  8. 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?

  9. I have a Bosch rechargeable NiCad battery operated screwdriver, not used a lot, has lost its charge and cannot be recharged using the supplied battery charger. It has come to my attention that if a NiCad battery is not used for some months then it will lose its charge and cannot be recharged. You would think the instruction book would provide appropriate advice or warning in the instruction book. The tool is useless now. Is this a common problem?

  10. 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?

  11. My battery has started getting very hot while charging. Vents are clear and not covered. Any suggestions?

  12. 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??

  13. 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

  14. I have 2 batteries for my drill and I was keeping one plugged into the charger. When I went to use the drill, the battery was dead. I tried plugging the charger and bettery into several plugs and even swapped out the battery to my backup but the light on the charger won’t come on. Did I fry my charger?

  15. Sorry if already been asked, but when charging is complete, if I switch off the charger but leave the battery on the charger, will this drain the charge? (Ni-Cad Battery) Thanks.

  16. 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,

  17. 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?

  18. 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 ?

  19. I hate it when my cordless drill gives up in the middle of a job. It seems that the supplied battery packs just don’t cut it. So I opened up the battery pack and replaced the NiCads with much longer lasting NiMH batteries. Now I get a much longer use between charges.

  20. 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 ?

  21. I’m confused about storing a NiCad fully charged or not. One site I visited says to discharge them. You say keep them charged. I went through 4 batteries in my previous drill and have a new one with NiCad batteries ordered. I would like to know what I did wrong. It will sit for quite some time between uses. Please reply by email.

  22. Lithium-Ion batteries should in theory work forever because they work on the movement of ions. However, like any product, their general treatment and care, temperatures and aging process will also have an impact on these type of batteries.

  23. I have a 40volt rechargeable battery. Battery will not accept charge. When I place it on the charger, the battery keeps flashing green lights. Thinking the battery is charged, I try to use it. But to my surprise nothing happens. Does the flashing lights mean something? Or is the battery shot?

  24. 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.
    214 499 7537.

  25. 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.

  26. MOST batteries cannot be ‘reconditioned’. Only if they were falsely deemed ‘dead’. BattAussie batteries usually short out or the plates get worn out, you cannot fix them. Alkalines cannot be recharged or conditioned. Lithiums die when they die.

  27. 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.

  28. 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.

  29. When I did get to use the drill, I sometimes would deplete one battery and put it on the charger while I switched to the other battery and continued working. By the time I drained the second battery, the first one was still barely charged.

  30. 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

  31. 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

  32. 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


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