Cordless Drills & battery replacements

  Diemmess 10:23 07 Jan 2012

For those who like to make and mend. A thread long since locked (March 2010) enter link description here

With little to lose I bought 8 NiMh Sub-C tagged and then did nothing with them! They remained untouched for nearly two years.

Yesterday with one battery pack almost useless I built the "new" cells into the old case. The pack showed 4.6v !

Plonked it on the fast charger and watched for signs of distress. It took about an hour before the green light changed to flashing.

Battery fresh off charge read 11.1v and this morning still runs at a speed I haven't seen for ages.

The charging unit is clearly happy with these cells, and didn't heat up any more than it has done in the past with Nicads.

Posting this because with care it is possible to give a whole new lease of life to an otherwise useless tool.

L-ion batteries are NOT suitable as direct replacements for NiCad or NiMh, don't even try them!

  WhiteTruckMan 10:56 07 Jan 2012

I did a virtually identical thing with a cheap 12v drill over a year ago. That cured the 'dead battery' problem, but still left me with the problem of preventing it. The drill has a cheap powerpack type charger, similar to an old phone charger, not really suitable for extended charging. Plus, I thing leaving something on charge 24/7 does it no favours. So I bought some cheap £1 timer sockets (B&Q I think) and now it lives permanantly plugged in but gets 10 minutes of charge a day to keep it topped up unless it gets used, in which case I give it a longer charge. result after a year is a permanatly charged battery with no loss of capacity, and a lot cheaper than a specialist charger.


  spuds 12:11 07 Jan 2012

I am one of those unfortunate people who use 'rechargeable' batteries on many pieces of equipment.

At present we are having 'poor' charging problems with 1.2.3 million candle power lamps, which is turning out to be a case of replacing the items instead of replacing the batteries?.

We have even bought 'testers' for checking the batteries, because we found the re/green lights on chargers not always reliable. But alas some of these 'testers' in themselves have not proved accurate enough, and we see no point in spending £100+ on a 'specialist tester'!.

  wiz-king 12:37 07 Jan 2012

The high candle power lanterns usually us lead/acid cells - at least mine do - and they need discharging and recharging every month or so. I find I have to replace batteries every few years and get them from MDS I also get batteries for my UPS's from these people.

I have a varied mix of re-chargeable cells in various bits and have NiCad, LiMH and Li-ion and enough chargers to sink a battleship!

  Diemmess 12:54 07 Jan 2012


Good for you! That is a splendid idea, I think current models are deliberately changing the physical specifications because sooner rather than later, they know the whole tool will need replacing. .......... A son's battery was sealed in manufacture and there is no non-destructive way to dismantle it.


I know just how you feel and my family experience with that type of torch is that a terminal failure will occur within about 3 years.

The lead acid battery failed in one torch and the other blew the circuit board caused a shortand and took the charger unit with it. For the money they produce a powerful light, but that is all!

  spuds 13:01 07 Jan 2012


Like you, we have enough 'various bits' to sink a battleship, and obtained our replacements from a reliable source. But in the end modern technology, including battery power, seems to baffle even the best of us ;o)

One thing that I will say, is that we have a cooker that must be the best part of 20 years old or more, with the same standard Ever Ready battery that was supplied with it for lighting the ignition. Whether this is a record I wouldn't know, but keeping the battery warm appears so!.

  SparkyJack 14:51 07 Jan 2012

I Wonder just wonder mind you

Having acquired a couple of discarded laptops in recent times- each with a dead battery. and having looked for on the net for suitable replacement- and did not proceed.

I took one of those batteries apart and lo a cluster of AA size cells paralleled up to give the required voltage.

Hmmm- would it be possible too do a rebuild at moderate cost?

Any one tried it?

  SparkyJack 14:56 07 Jan 2012

This got me looking on dear old 'G' . What would we do with out it

And a whole page of how to- rebuild that battery came to light [enter link description here][1

This is one example.

  SparkyJack 14:58 07 Jan 2012
  SparkyJack 15:00 07 Jan 2012
  Aitchbee 21:38 07 Jan 2012

My elderly aunt, 'Auntie Annie' was deaf, and she always asked me to exchange her battery for her hearing aid...Fond memories...but the button battery technology has not changed much in 40 years. I bought some batteries, last week, and they only lasted for a month.(watch batteries...made in China).

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