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Power tool queries

Repacking cordless battery packs

We received queries from two readers asking about replacing and/or upgrading battery packs in cordless power tools:


Nickel-cadmium (NiCd) batteries were used extensively in cordless tools in the past but these have since been replaced with nickel-metal hydride battery (NiMH) and lithium-ion (Li-ion) batteries for the most part. I’m sure many DIY’ers and woodworkers have cordless drills with old NiCd batteries that no longer work. These end up lying around gathering dust and taking up space in the workshop. Is there a company in South Africa that can convert these old batteries into Li-ion battery packs?

Ken Pauls, by email


In your May 2015 issue you featured an article headed ‘Power up’ discussing the different battery types. The article highlights the problems with the NiCd battery packs and I have been told that it is possible to have these batteries repacked. I have the Triton 18V Cordless Drill powered by 2.0Ah NiCd batteries (two supplied). This has been a wonderful tool hampered by poor battery performance right from the date of purchase! They run down extremely quickly and I always need to have one on charge while using the other. My questions are: Is it in fact possible to have these batteries repacked? Where can I have this done? Is it economically viable?

Eugene Taljaard, by email


Ed replies: You are not the only readers who have asked this question. It must be said that while newer battery technology is superior, NiCd remains the most durable of batteries and is more able to withstand more abuse. The answer to all is: Yes, it is technically possible to upgrade any battery pack, but with varying levels of complexity and all have been found to be cost inhibitive.


While possible, converting to Li-ion is not recommended as gearing and internal circuitry is customised on models that come with Li-ion battery packs in addition to specialised chargers. The cost of burnt out wiring, motors, batteries and the possibility of creating a fire hazard makes the risk too high to justify, even without consideration of the specialised charger required.


When it comes to NiCd you can replace the battery cells with the same cells, or cells of a higher capacity, such as NiMH 3.0Ah and still use the same charger. Unfortunately, after some research I found that the cost of replacement is not economically viable. Whether you choose to upgrade with NiMH or stay with NiCd, each cell will cost around R100. For an 18V pack, you will require 15 cells (1.2V) at a total cost of R1 500. Original packs from the maker should cost less than this. Therefore, unless you are unable to source packs from the original manufacturer, building your own packs is not a viable option. Cordless tools using NiCd and NiMH normally use sub-C size cells, which can be bought from most hobby shops and battery distributors such as Carter Agencies.


Brad point wood bit increments
I have been looking for brad point wood drill bits in standard metric sizes +1/2 - 4.5mm in particular. Unlike steel bits,
I have never encountered half sizes in wood bits. Extensive enquiries in this regard have proved fruitless, and I hope you
can shed some light
on this subject. Are they available at all, and, if so, where?
Roland Zacharie, by email

Product manager at Vermont Sales, Greg de Villiers replies: Thank you for the enquiry.  The simple answer is yes you do get half size brad point drill bits, but demand is low so retailers don’t stock them. One of the reasons is that the nearest mm would normally suffice when working with wood. For instance, a 4mm pilot hole would accommodate a 4.5mm screw. In addition, the tolerances provided by wood are greatly different to that of steel. I have contacted Alpen, our drill bit manufacturer, for comment and we will advise should we receive a useful response.


For more information contact Vermont Sales
on 011-314-7711


Spray-painting conundrum
I am looking into spray-painting, but am not too sure which product to buy. There is the Bosch PFS Fine Spray Gun and then the normal spray gun that works using a compressor. I want something for normal DIY use, i.e. spray-painting metal burglar bars, palisade fencing, wooden furniture etc. What is better – the Bosch Spray Gun or the normal air compressor with the spray nozzle? 

The other query I have is what size compressor is best – will a 24 litre compressor, which seems to be the standard size available at hardware stores such as Game or Builders Warehouse, work or must I consider a bigger size compressor; if so, what size? 
Brett van Rooyen, Centurion

Bruwer Leykauf, our technical consultant, replies: 

Should you want to use the spray gun for painting only, then the Bosch PFS is easy to use and very effective. However, by going the compressor route, i.e. compressor and separate spray nozzle, you are not limited to painting only. 

It is important to note that a 24 litre compressor will be suitable for the painting projects outlined and for inflating tyres. I suggest you consider purchasing a 100 litre compressor as the uses are endless. Just add different air tools, i.e. for airbrushing, sandblasting, polishing, sanding, grinding, etc. 

Using a 100 litre compressor the air delivery is sufficient to run a HVLP (high volume low pressure) spray gun and an EPA (Environmental Protection Act) spray gun.

For more information contact Bruwer on 083 234 7124 or email

Tenon maker 
I want to make log furniture and am looking to purchase a tenon-making tool. Where in South Africa can I get one? 
Leon Burger, by email 

Ed replies: 

You can purchase the mortise and tenon cutter from Hardware Centre, which also offers a delivery service countrywide. Contact Viv Martin on 011-791-0844 for more information.

Bruwer Leykauf, our technical consultant, suggests:

There are quicker and easier options to consider when making mortise and tenon joints using logs that are 50mm in diameter or more. 

You can make the joints by hand using a hand saw and chisels or a circular saw and chisels. Simply measure the tenon part of the joint and transfer the size of the tenon onto the logs where your slot is going to be recessed. Once you have marked out all these areas, cut out the mortise slot and tenon joint using the hand saw or circular saw and chisels.

For more information contact Bruwer on 083 234 7124 or email

Charging batteries
I have a collection of Ni-Cd cordless screwdriver batteries that no longer hold their charge. Is there an effective and safe way to rejuvenate these batteries?
Roland Prochassek,, Johannesburg

Ed replies:
Dicky Beukes from Cordless Tool Rescue specialises in the refurbishment of batteries. He replaces the cells inside the battery. You said they are Ni-Cd batteries so it should not be too costly.


Contact Dicky on 011-678-8959 or 083-700-6185.

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