Black & Decker battery charger fix

Black & decker with a kid

Behind this long title, I will simply tell you how to fix charging problem with Black & Decker cordless drills.

In my home toolbox, there was a broken cordless drill that had some battery issues. The engine-tool had not been used for a while, so the two 14.4V batteries were totally discharged, in a state called “deep-discharge”.

The problem was I can’t charge these batteries anymore: when I plugged the batteries onto the charger, the red led that indicates the battery isn’t charged yet light up for 1 second, and then, the green one light up…

So my first thought was something is going wrong inside the charger. I noticed several time (when all was working) that the battery charger was really hot.

The first defy was to open the shell of it. It was really painful, because Black&Decker uses some of these hex screws called “security torx”, with a cylinder in the middle:

The second problem with these screws are that two of them are in a tiny hole, and most of screwdrivers haven’t the right diameter to enter in.
The solution is a bit “Mac-Gyver approved”: I took another drill with a  metal bit, and tried to break the head of the screw. Finally, I was able to open the box: the heat was so high that the plastic around the screw melted.

A first look on the circuit-board, and I found the issue: the charging resistor has been un-solded because it was to warm during previous charging. It is the big grey one, annoted “R2” on the board.

After fixing it, I simply closed back the charger and tried to charge my two batteries. Unfortunately, I had the same problem: red led for 1 sec, then green led.

After some research, I understood that the two batteries was to low to be able to charge (checked with the multimeter). For this drill-charger, the voltage of the battery must be higher than 7V. Mine was under 1V, so it needed to be boosted before charging…

On Catmacey’s blog, I found a similar charger story about a Black&Decker drill, followed by a little guide that explains how to revive NiCd batteries with a throwable camera with flash, and a Youtube video from dial2fast.
Moreover, this is another complete how-to using a throw-able camera trick.

It allowed me to go over the 7V needed by the charger. “In fine”, the red led charging lighted up until the complete charge of the battery. My drill was working back then!

Ressources:

http://www.contractortalk.com/f40/nicad-battery-fix-repair-guide-36047/

http://www.youtube.com/watch?v=e5sO1OdEwEQ

http://tech-tut.com/?p=721

http://www.youtube.com/watch?v=1e8hHLyXAyQ

http://catmacey.wordpress.com/2009/03/28/reviving-a-dead-nicad-battery/

http://www.instructables.com/id/Bring-Dead-Ni-Cad-Batteries-Back-To-Life/

9 Responses so far.

  1. Jim says:

    What was the model Black and Decker charger? Was it by chance a PS160? Probably not since the PS160 is a sealed unit with no screws and apparently has to be cut open to repair. I am wondering how to reseal once the repair is completed?

    Thank you.

    • Louisb0b says:

      This is the model of the charger :

      De owl-black.net

      But the screws in my charger were on the bottom of the charger : there are 4 holes where you have torx-like screws, as shown on the picture bellow. I needed another drill to “cut” the head of the screws. Then I replaced them with brand new philips screws, easier to remove.

      De owl-black.net

      Regards

  2. Andrew says:

    I’ve found that if I leave my charger on “green” for about 20 minutes and then turn it off and on at the wall it starts charging. I suspect mine just needs some time to “warm up”.

  3. cedric says:

    Hi

    Do i read the resistor correctly? (mine blow up and cant be read anymore)

    red-brown-black-silver

    21 Ohms 10% 2 Watt resistor

    thanks!

  4. Carlos Santos says:

    Good Morning,
    I would appreciate if some friend sent to my mail some photos of this charger, with the references of the transistors visible, I have a charger of these to repair, but the transistors have already been removed.
    Thank you.

  5. Tony says:

    Hi everyone,

    I’ve experienced the same issue with the charger. To open the charger you need Torque key model. I was lucky to buy them in TX Max (tools section) set of 9 keys cost me £4.99, you can get them on Amazon as well for less than £5.00
    It’s very tricky to open at first but with the right tool you won’t have any problem.
    See link
    https://www.amazon.co.uk/Blackspur-BB-WR256-Torque-Security-Key-x/dp/B003LQIR6Y/ref=sr_1_3?ie=UTF8&qid=1486235701&sr=8-3&keywords=torque+key+set

    I hope it helps to anyone.
    T

  6. carolyn says:

    when the light is green what dose that mean?

  7. carolyn says:

    when the light on my 18v battery charger for my weed eater is green is it ready ?

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