Dewalt drill batteries not charging update.

[stryped]

x-no-archive:yes

As I said before, when I put the battery pack on the charger. There is
a constant beep of a light on and off and the directions say "replace
battery pack" I left it on overnight like this. This morning the light
was steady like it was supposed to be. The voltage coming out of the
battery pack was only 5 volts. I put the battery back on the charger
and it blinked again to mean "replace battery pack".

How much voltage is supposed to come out of the charger? When I checked
yesterday on dc voltage on my voltmeter it said 50 volts or somethign
like that. Is that correct? Am I doomed to buy a new battery pack? They
are 80 bucks at lowes. Batteries plus will rebuild mine for around 60.

 

[Bob Urz]

x-no-archive:yes

As I said before, when I put the battery pack on the charger. There is
a constant beep of a light on and off and the directions say "replace
battery pack" I left it on overnight like this. This morning the light
was steady like it was supposed to be. The voltage coming out of the
battery pack was only 5 volts. I put the battery back on the charger
and it blinked again to mean "replace battery pack".

How much voltage is supposed to come out of the charger? When I checked
yesterday on dc voltage on my voltmeter it said 50 volts or somethign
like that. Is that correct? Am I doomed to buy a new battery pack? They
are 80 bu

If your brave, take it apart and measure the voltage across every
individual cell. Chances are one or more are defective in some way.

Bob

 

[stryped]

x-no-archive:yes

I took it appart yesterday. All the cells are connected togther. How
can i measure individual voltage with them connected togther?

 

[Bob Shuman]

You simply connect the voltmeter leads to each cells positive and negative.
If you are saying you can't access the positive contact since the
interconnection is too short (most times these are simply folded over and
can be unfolded to gain access), then measure from the negative case on one
battery to the negative case on the next since the positive should be
directly connected to it.

A fully charged (good) cell will measure approximately 1.2V. Bad (shorted
or leaking) cells will measure zero or close to it. Find out how much
Batteries Plus charges for the cells and for spot welding on the solderable
leads and then compare this to their rebuild price to determine which
alternative to take.

You also can look on the Internet for a cheaper source, but you take your
chances when doing this on quality.

Bob

 

[Ken Layton]

The Dewalt batteries currently made today have screw together cases to
make it easy to get inside them. Older Dewalt batteries had a sonically
welded cases you'd have to carefully cut open with a hacksaw or Dremel.

I fixed a Dewalt battery charger for a friend a couple of months ago.
It had a shorted diode (the bad one had obvious burn marks on the pc
board). I used an NTE 5809 to replace the original one. BTW you'll need
a Tamperproof Torx T-10 to open the case to access the pc board.

 

[ray13]

1). 50 volts is the open circuit voltage. That's just the nature of the
beast.

2). The case of each cell is minus or negative. So measure from case of
the first cell to the case of the next cell will give you one cell
voltage. You don't need to break it open unless you can't get to the
cases. Which are in plastic sleeves. Puncture the sleeve and connect to
the case.

3). Drain all cells down to 1.1V then recharge. If one cell gets lower
in voltage than the rest, it will upset the string and the output will
suffer.

Or just bite the bullet and pony up for a new battery.

 

[Vey]

3). Drain all cells down to 1.1V then recharge. If one cell gets lower
in voltage than the rest, it will upset the string and the output will
suffer.

I'm surprised that no one has mentioned anything about these nicads
being so discharged that they act as if they will never take a charge
again. I have had several packs and separate batteries act this way.

I just put them in and out of the charger, then rest a while, then start
again until finally it got a tiny charged forced upon it. Then it would
accept a normal charge.