Need help with cordless drill charger

Discussion in 'General Electronics Chat' started by 120volts, Sep 26, 2014.

  1. 120volts

    Thread Starter New Member

    Sep 26, 2014
    12
    0
    Hello. I am a first-time poster. Thank you for letting me onto this forum. I need help with a cordless drill charger that is not charging properly. It is a sears craftsman 19.2 V charger that I bought used. It will not hold a charge and the battery appears okay. I did a voltage test at the charger terminals and it initially showed bouncing voltage from 0-3.2 V. Later, when I redid the test, it showed a steady 5 V. This is still a far less voltage than what it should be for charging purposes. After some difficulty removing the security screws, I have it opened and the circuitboard is exposed. There are no cold soldering joints to be found that I can see. And there are no burn marks anywhere. There is one large and one small can capacitor that are not bulged or obviously leaking. And there are several smaller capacitors that appear normal. I have not tested any of these. Where do I begin diagnosing this circuitboard? I will try to attach some pictures but I am not familiar with this forum site so I may not be successful. Any help is appreciated!
     
  2. 120volts

    Thread Starter New Member

    Sep 26, 2014
    12
    0
    How do I upload pictures. Things keep spinning and nothing happens.
     
  3. tcmtech

    Well-Known Member

    Nov 4, 2013
    2,044
    1,678
    The charger is probably just fine. It's your battery thats the problem.

    The brand of cells craftsman uses in those batteries are junk. I have about 10 -12 of those 19.2 volt batteries now and I can assure you that not one of them ever made it a year before they started doing exactly what you are describing. They usually charge just fine and test good but a few days off the charger and they are usually half dead or worse despite never having been used.

    Personally I would recommend buying a new battery and then taking the bad one back in a few months and exchange it for a new one under the new batteries one year warranty coverage. Believe me the sales people see so many of these batteries die under warranty they wont even question whether or not the bad battery you brought back is really the one you bought a few months earlier or not.
     
    120volts likes this.
  4. 120volts

    Thread Starter New Member

    Sep 26, 2014
    12
    0
    I did not know that about these batteries. Thank you for that. I forgot to mention something important: the battery charger hisses. Is this normal? The hissing is what made me think it might be a faulty charger. I have tested other chargers and the output voltage was well beyond the battery voltage. A 5v charge is extremely low. Is it not?
     
  5. Gdrumm

    Distinguished Member

    Aug 29, 2008
    684
    36
    I agree with TCMTECH in that these are worthless batteries.
    My new ones (I bought 2) lasted about 1 year.

    They can be re-done, with better longer lasting cells, but I wouldn't know what brand to advise you to get.
    My Black and Decker drill batteries last a couple of years.

    Perhaps a new drill. with Lithium Ion batteries would last much longer?
    They certainly cost more.

    Good luck.

    A hissing charger doens't sound good either.
     
  6. bertus

    Administrator

    Apr 5, 2008
    15,649
    2,348
    Hello,

    Is the charger hissing when the battery is connected?
    If so, it looks like the charger is shorted by the battery.

    Bertus
     
  7. 120volts

    Thread Starter New Member

    Sep 26, 2014
    12
    0
    Charger hisses regardless if the battery is charging or if the charger is plugged in without the battery. That is why I am suspecting it is the charger and was hoping to troubleshoot it. I understand about the poor battery and that could be a contributing factor.
     
  8. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    Be cautious working on the circuit. It probably is a transformer-less design and the circuit is hot relative to other appliances and ground.
     
    Last edited: Sep 26, 2014
  9. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    Get a piece of plastic that is rod shaped. I have used a tooth brush in the past. Press one end to the base of your ear and touch the other end to components. This will help you find the part making the noise. Remember...PLASTIC.

    Also, how many connections does the battery pack have?
     
  10. 120volts

    Thread Starter New Member

    Sep 26, 2014
    12
    0
    Lestraveled: The charger does have a transformer. How do I upload photos on this forum? I tried but the uploader just keeps spinning and nothing happens. Maybe it did not have its coffee this morning. Great point about listening with a toothbrush or rod. Can I use a auto mechanic's stethoscope that is heavily taped up since it's metal? I had not thought about listening it to the hissing this way. I won't be able to get to this until this evening.
     
  11. 120volts

    Thread Starter New Member

    Sep 26, 2014
    12
    0
    Oops I forgot: the charger has three connectors.
     
  12. bertus

    Administrator

    Apr 5, 2008
    15,649
    2,348
    Hello,

    You can upload photos and other type of attachments using the "Upload File" button on the right beneath the reply window.

    Bertus
     
  13. tcmtech

    Well-Known Member

    Nov 4, 2013
    2,044
    1,678
    You can buy stock lithium ion type batteries for the craftsman 19.2 devices but to be honest I rather hate them. They are so overprotected they are nearly useless. :mad:

    They get ran hard and heat up and just shut off.
    They start running low and they just shut off.
    They get left in the sun too long and warm up and they just shut off.
    They get too cold and they just shut off.
    Fast charge them and try to use them while warm and the just shut off.
    Try to charge them when they are warm and they won't charge until they cool down.

    Granted they may last longer life span wise but the overall inconveniences of not knowing when or where they will go into a protection mode and become useless will have you cussing them worse than the nicads that just don't hold there charge for more than a day or two.

    Personally the best rebuild I have found is to repack the batteries with the tabbed sub AA high capacity type. You can get more Ah in a battery at less cost than going the sub C cell route. ;)
     
  14. tcmtech

    Well-Known Member

    Nov 4, 2013
    2,044
    1,678
    Be cautious working on the circuit. It probably is a transformer-less design and the circuit is hot relative to other appliances and ground.

    There are at least three versions of those charger power systems now. Normal transformer, SMPS, and capacitive coupled transformerless.

    Given the hissing sound I suspect his is the SMPS version.
     
  15. 120volts

    Thread Starter New Member

    Sep 26, 2014
    12
    0
    Sorry I did not make this clearer in the beginning. I have a bundle of tools including some very nice Dewalt cordless power drills etc. that are my workhorses. I got this Craftsman drill and charger as a extra drill to keep around the house. I bought it used and I knew there was no guarantee on how it would work. I do not suspect a battery problem: when I got it, the battery was already fully charged and the drill ran for four months doing light household duty. There was no hissing when I first got the charger and battery. I only noticed it now when I am about to recharge. I got it for cheap and I wanted to experiment in trying to fix it if there was a problem. I am a total DIY kind a guy. . I just want to see if the charger is actually working or not. It just seems the voltage is way too low at 5 V output. There is no way that it can charge any battery with that low output. Anyone have any experience with their voltage output on a similar charger? One of my Dewalt is outputting 30V.
     
  16. tcmtech

    Well-Known Member

    Nov 4, 2013
    2,044
    1,678
    Most of the craftsman chargers are smart chargers so their open circuit voltage is meaningless. What the voltage is at when the battery is in full charge is the reading that matter.
     
    120volts likes this.
  17. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,571
    2,381
    I have one where the battery would no longer hold a charge, I opened up the battery unit and there were 14 1.2v 1300mAh Ni-Cad cells, the replacements can be had on ebay to rebuild.
    Max.
     
  18. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    Here is an outfit that I have used for rebuild kits for battery packs. Their prices are great, very fast service and they were home when I called them. They list Craftsman on their rebuild list. I bought two Dewalt 14.4 kits a year ago and they work great!

    http://www.springgrovebattery.com/index.html
     
    shortbus likes this.
  19. 120volts

    Thread Starter New Member

    Sep 26, 2014
    12
    0
    Ah. Thanks. That would make sense then. I'll look into another battery pack then. Thanks everyone!
     
Loading...