re-celling batteries

I suspect this has been well covered before but...

I have a cheap Direct Power (Screwfix supplied) drill. Unsurprisingly the Ni-cads are failing after 12 months or so use.

I looked at various battery supply sites and failed to find a match.

A complete new drill plus 2 batteries from Screwfix is around 35ukp which is roughly the cost of a single *quality* battery elsewhere.

With global warming etc. in mind, I am reluctant to throw away a working tool!

The Direct Power batteries are easily disassembled so re-celling is an option. So.... assuming I have the cheapest possible cells... what are my options?

Will better replacement cells work OK with the supplied charger? Can I change to Ni-mh or whatever? Who does one go to for advice and supplies?

regards

Reply to
Tim Lamb
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may be a start for pure cells.

about 85% of the cost of thee tools is in the batteries anyway.

Te motors are a couple of dollars and the gearbox isn't much more..

Reply to
The Natural Philosopher

Two things - cheap cells will fail quickly too. And it's possible the charger is the cause - or contributing to - the short life. Overcharging just once will shorten cell life.

I had the same dilemma with my B&Q 18 volt cheapie. New decent cells (Sanyo) made the actual drill perform *far* better - the lower internal impedance gave better low speed control and torque. I also modified the charger to a 1/10th constant current type - and use a timer to prevent overcharging. The charger on mine consisted of a simple DC power supply with a series resistor - ie no electronic control. A look inside the base should show if yours is this poor.

You might look for special offers of a decent brand same voltage battery on Ebay etc - and rob that of its cells. They are usually the same size. I paid near the same price (trade) for the Sanyo cells as the drill cost new. But they're still fine some 4 years later.

Reply to
Dave Plowman (News)

What's global warming got to do with it?

What voltage is the pack?

I'm tempted to scrap the batterry and run mine of one of those emergency jump start thingies but then they're less than 12V.

AJH

Reply to
andrew

Eh? They are a standard SLA 12v battery so as much 12 volts as anything else that says it has a 12 volt battery.

But a cordless drill powered from an external pack isn't cordless any more...

Reply to
Dave Plowman (News)

Yes but the two cordless tools that I use which have duff batteries are both less than 12V, my 18V one still has a good battery.

I know but it's a cheaper option than buying new cells. Actually for the sort of work I do I often find it easier to tote a small 2t generator around for the angle grinder or sds drill. Typically my small cordless angle grinder would just cut one hydraulic hose on a charge.

AJH

Reply to
andrew

How many cells have gone? (measure cell voltage under load)

cheers, Pete.

Reply to
Pete C

True, but it shares possibly the most important feature of a true "cordless" tool, in that you aren't dependent on having a mains socket local to the work you are doing.

Reply to
Bruce

Somebody somewhere has to get out of bed and make a replacement drill. This has to be shipped, probably halfway round the world, giving employment and hope of a pension to who knows how many others. The bottom line net effect of this is to encourage procreation which is the last possible thing I would wish the world to indulge:-)

24V

I'm not criticising the value/use I have already had, just looking to extend life without much pain.

regards

Reply to
Tim Lamb

er... OK. Thinking how to load the batteries and have access to the connections. I'll get back.

My suspicion is that I have internal leak issues rather than failed cells. A few cycles of use and they perform better. Unfortunately they are not used daily so what is expected to be a fully charged battery only gives a short period of output.

I also have to check for *sophistication* in the charger circuit:-)

regards

Reply to
Tim Lamb

Mixing old and new cells will be false economy. I use Euro batteries for replacement cells. Excellent service. If you order from a email address you've not registered with them before you get 20% off your 'first' order Also worth looking with google for discount codes sometimes these are greater than 20%

Bob

Reply to
Bob Minchin

How often does this occur for DIY? And if it were a regular occurrence for me I'd get a generator. I use cordless only for the convenience of, err, not having a cord. ;-)

Reply to
Dave Plowman (News)

I see your point, but I was thinking of the last time I used a cordless drill, which was to fix some brackets in my caravan. I didn't need a "lack of cord" merely something that worked without needing a mains connection.

Reply to
Bruce

In message , Tim Lamb writes

Battery was flat and accessing terminals plugged into the drill not easy. What I have done is to look at the individual cell voltage on charge. Lowest 1.37V (4 cells), highest 1.52V (1 cell) mostly around

1.4V

The cells are by Huanyu type GNY 1.2V and 1300mAh

The charger, a pox on 3 legged security screws, is *sophisticated*. They were just changing from Germanium to Silicon transistors when I knew anything about electronics but there were 4 hefty diodes arranged as a bridge, a mystery encapsulated box possibly a relay, an i/c and various other bits and bobs.

Type FCS03-240, Ni-cd JOCC2-240

regards

Reply to
Tim Lamb

In message , Bob Minchin writes

OK Bob, makes sense.

regards

Reply to
Tim Lamb

In message , "Dave Plowman (News)" writes

It seems to have knobs and bells beyond my ken:-)

I have an idea the charge current is connected by an encapsulated relay as there is an audible click as the LEDs change over. Unfortunately the legend on the i/c was hard to read without a lens but I can look more carefully if it helps.

Not that many 24V batteries about...

regards

>
Reply to
Tim Lamb

Right, what I meant was the cell voltage while the drill is being run rather than charged. The duff cells should soon drop to zero while the others stay around 1.2.

If only a one or two cells are gone I'd just cut them out (dremel across the 'strap' where spot welded to duff battery) and solder thick wire in there to bypass them :)

Might be worth using the charger on a timer from then on too ;)

In the meantime an unwanted cordless drill/vacuum might turn up on Freecycle or Ebay locally and some sub C's could be had from that.

If you want a project how about getting a LiPo RC charger and re-cell with '20C' or '25C' LiPo packs >:)

cheers, Pete.

Reply to
Pete C

I know what you meant:-) Next time I have three hands, I'll try.

Yes. Having noted the prices for *C* cells I'm not so happy about replacing a full set of 20.

Ummm... is there any easy way of finding out how the existing charger operates?

This is rather deep water for my wellingtons:-)

regards

Reply to
Tim Lamb

Its hard for this to be cost effective unless it's a quality drill. However I recently bought from a B&Q clearance table two 9.6v Bosch drill battery's for £3.99 each. They were the standard sub-c cell quite easy to make one quite good 12v battery pack.

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Reply to
Mark

a 12V SLA will never give the performance and deep discharge capability of a NiCd or NiMh pack though.

Reply to
John Rumm

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