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Dave Plowman
 
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Default How to test a cordless drill/charger?

In article ,
Mick wrote:
My trusted B and D drill/screwdriver has decided not to recharge. Can
anyone guide me to a website that will give simple instructions on using
a Multimeter ( LCD display) to test whether it's the drill or the
charger at fault......Please :-)


A very simple check would be to measure the output voltage of the charger
while it's disconnected but switched on - this will be *very*
approximately the same as the voltage the drill works on, although it
might well be twice or more higher off load.

If there is a voltage there that is higher than the drill voltage, the
next step is to measure the current flowing while on charge. This will
require some dismantling to wire the meter in series with the power
supply, and without knowing the individual set up it's not easy to give
advice - except not to mess with actual part that contains the mains
transformer.

But by far the most likely thing is that the battery has failed. If the
drill has a plug in battery, I'd take a chance and just replace it - if
you can find one at a price less than a new drill. If the batteries are
built in, as on some screwdrivers, you'll need to open it up for access.
Spare cells are available from Maplin etc - you'll need Sub-C size and
tagged so they can be soldered. But again, these might cost as much as a
complete new unit. Sad but true. A separate battery pack can again usually
be opened with some ingenuity and the cells replaced, but each cell
(divide the device voltage by 1.2 to tell how many it has - ie a 7.2 volt
drill will have 6) will cost between 2-4 quid depending on spec and where
bought.

--
*Why isn't there a special name for the back of your knee?

Dave Plowman London SW 12
RIP Acorn