[Top] [All Lists]

Re: [Shop-talk] dewalt battery charger testing

To: "David Scheidt" <>, "john niolon" <>
Subject: Re: [Shop-talk] dewalt battery charger testing
From: "Arvid Jedlicka" <>
Date: Wed, 22 Dec 2010 10:11:30 -0600
I also think there is a temperature sensing terminal on the battery that the 
charger needs to see before it will apply a charge. At least there is on my 
Hitachi charger. So unless you can simulate a real battery in the charger 
socket you will get zero volts on the two battery terminals.

Maybe some small wires jammed in along with the the battery will allow you 
to determine the charging voltage being applied to the battery. Of course I 
take no responsibility for the small wires going hay wire and causing the 
charger to assume either the dead or fire mode that David mentioned ;-}


-----Original Message----- 
From: David Scheidt
Sent: Wednesday, December 22, 2010 9:47 AM
To: john niolon
Cc: shop-talk
Subject: Re: [Shop-talk] dewalt battery charger testing

On Wed, Dec 22, 2010 at 10:25 AM, john niolon <> wrote:
> I'm having trouble charging Dewalt batteries... some it may be old
> but I'm wondering if my one hour charger is dying... B  Dewalt 9107 B one
> charger B  when I put a meter across the contacts down in the charger I 
> read
> d.c. voltage. B although the battery is getting warm and slowly taking a
> charge... I had a completely dead 12v battery and started charging it with
> hotter power supply 26volt B for a few minutes... it came up to about 8
> and I then stuck it in the 9107.... B 4 hours later it's up to about 10
> ??? B  This is a 2.8 amp charger and should do better than this...
B discounting
> a bad battery pack... how can I test the charger ???

As i recall, that's a multi-voltage charger.  The batteries have
terminals that tell the charger which voltage they are, depending on
how they're wired.  I have no idea what the pinouts are, but I'll say
this: if it works at all, it's fine, and your battery is shot.  (There
are basically two failure modes with this sort of battery charger:
dead, and fire.)  Test it with a known good pack.  If you don't have a
known good pack, tis the season for good deals on new drills...

David Scheidt
Suggested annual donation  $12.96
Suggested annual donation  $12.96

<Prev in Thread] Current Thread [Next in Thread>