oldish Parkside drill charger

[G r o g]

My Parkside drill charger has suddenly come over all poorly. It worked fine 2 weeks ago when last used but now it won't charge. I checked the voltage of the charging and it read +- 13.8 volts. It's an 18 volt charger. It has 6 security screws holding it together so I wondered if there would be anything in there that I could fix/replace. It's been a good drill and I'm reluctant to throw it out so does anyone know if the charger might be repairable? I know a replacement would be cheap enough but I don't want to throw away a perfectly good drill for landfill. Grateful for any help. TYIA

[Archibald Tarquin Blenkinsopp]

The output Voltage might not be the best indication. It might be difficult but try measuring the current through the battery first.

The battery is the weakest link.

If you cannot access the chargers "gubbins", the drill battery should have the rating marked on it. a foolproof way of proving the battery is to use a resistor or load such as a small bulb and feed the battery from a DC supply of a little over the battery Voltage. Select a resistor/ load to drop the charge current to 10% of the battery capacity and charge for 14 hours.

Keep an eye on the charge current and be prepared to tweak the load a little.

After 14 hours the battery should give an output for a reasonable time although as it's old it wont have the claimed capacity.

If it does, Toolstation stock security bits although beware as a lot of the screws are at the bottom of a deep recess and require a single thinnish driver.

If the battery has not charged, you can try discharging it fully and recharging, repeat until you find an improvement or loose interest.

If the charger is faulty, you can make a 14 hr charger with a load, but use a simple transformer and rectifier, not a smoothed PSU.

AB

[newshound]

If you give a few more details of the exact model (or at the very least, the battery type and voltage, and how many terminals), someone may be able to give you some better advice. If your batteries won't fit the current Parkside charge (ISTR you can now get a battery and charger separately for the current ALdi/Lidl tools) it *might* be possible to wire up your dead "socket" to the electronics of a new charger. But it is VERY IMPORTANT to get this right otherwise you may get exploding batteries.

[Archibald Tarquin Blenkinsopp]

The one tenth rated capacity for fourteen hours is applicable to all, is of no risk although for repeated cycles "dirty DC" is needed.

A "new" unspecified charger is a risky and stupid way to go without the relatively simple approach of defining where the fault lies first.

AB

[Brian Gaff]

On the other hand it could just be a duff diode in the charger of course. Brian

[Dave Plowman (News)]

Almost certainly the battery failed. You can get them fixed, but a new drill complete from Lidl will be better and cheaper.

[Archibald Tarquin Blenkinsopp]

13V DC suggests not.

Old charger and battery, the battery is a very strong favourite.

13V off load for a constant current charger is in keeping with expectations.

AB

[tabbypurr]

13v for an 18v charger?

[Archibald Tarquin Blenkinsopp]

Nicads/ NIMH batteries are charged at a constant current, if the current is constant, the Voltage will vary through the charge cycle.

A charger without a battery is not alwys going to produce the expected Voltage, in fact my Lenovo laptop charger gave nothing out off load, not even a mV.

Something I wont forget in a hurry as I bought a replacement and lo and behold it did the same :-(

AB

[tabbypurr]

I'd expect a budget brand nicd/nimh tool charger to be a simple current limited supply plus either timer or voltage triggered end of charge. Such a PSU would give over 20v offload.

NT

[G r o g]

Thanks for the info so far. A couple of new bits of info: The charger type is PABS 18-2SL; the drill type is JDA-180KA, the batteries just say 1.5Ah nicad 18v. A friend of mine who lives 14 miles away took the drill and batteries to see if any of his chargers would work. He forced the batteries into a "Challenge Extreme" charger and both batteries fully charged, so it looks like the charger is faulty, not the batteries. Unfortunately 28 mile round trip isn't really on for whenever 1 need a recharge! TYIA (again)

[newshound]

Some batteries have two terminals, some have three. Not much good using your algorithm to the wrong terminals.

[newshound]

Lidl are selling a Lithium ion battery plus charger at the moment. Not much help I know. IIRC some chargers are smart enough to charge both types.

[Archibald Tarquin Blenkinsopp]

Even budget devices can get quite intelligent, a bit like trying to measure the input of an op amp, the Voltage isn't always what would be expected, particularily off load.

Batteries are notorious, they depreciate from day one and if NiCad, they can be wrecked in a few different ways.

The half wave reccy and resistor is totally foolproof, I have resorted to it many times over the years.

A colleague in the TV trade used a TV mains dropper and BY127 mains reccy to charge his car battery direct from the mains. Happy days, he would probably have got a lot of sympathy and a slight reprimand if he fried one of the kids. Not quite the same these days :-)

AB

[tabbypurr]

One of my pre-war books advises charging a battery by connecting it across the mains lightswitch. Don't let anyone turn the switch on! Mad advice, but a lot of people could afford little else.

NT

[Archibald Tarquin Blenkinsopp]

Yes, twould work. It would have required DC mains though. Turning on the switch would have a detrimental effect on the contacts methinks :-)

Oddly enough it was probably illegal, I remember some of my old praccy wirelesses went to great lenths to discuss what could be powered from a lighting circuit. They got very philosophical and decided that a wireless was probably alright running from a lampholder as the valves gave out light. An iron was o/k too but it would have to be heated to cherry red to be "legal".

Variations on those themes kept the editorial and letters pages going for nearly a decade. I often thought about those little gems when reading New Scientists never ending series of gems arguing for and against relativity. i.e The magazine selecting and propogating a series of arguments for an extended period for the almost exclusive benefit of that periodical...

I can only assume that some companies put a charge on consumers based on power sockets and lighting circuits. I have no practical experience of these things as all this was history when I arrived on the planet.

AB

[tabbypurr]

I believe by the 30s that dual tariff approach was long gone. The dual tariff originally came about because there were no good affordable electricity meters, so people paid per light fitting & more if they also wanted a socket. Luxury!

NT

[Archibald Tarquin Blenkinsopp]

As simple as that!

I thought it must be, I never actually rcollect seing it explained or defined, just the many ways of trying to circumvent it being elaborated on.

Many thanks.

AB