soldering AAA batteries

[JohnW2]

A battery power rating determines what it can actually start or operate, whereas its work capacity only determines how long it can operate it.

As has been repeatedly said, 'the general public' do not necessarily use, or even understand, technical definitions - and that has to be taken into account when attempting to communicate clearly with them.

Perhaps a classic example is "Low Voltage". I would suggest that the vast majority of the general public have a view as to what this means which differs from the 'technically correct' definition.

 

[ericmark]

On every decent cordless I’ve ever used they’re a physical gearbox

I have found the same, maybe a speed control as well, but that is graduated, the switch is normally a gear change.

How/why do you think that could be the case?

I would assume the two batteries are wired in series to get 40 volts and two 2 Ah will become discharged at about the same time. But using a 2 Ah and 4 Ah in series seems wrong.

 

[JohnW2]

I would assume the two batteries are wired in series to get 40 volts and two 2 Ah will become discharged at about the same time. But using a 2 Ah and 4 Ah in series seems wrong.

Oh, I didn't realise you meant one 2 Ah and one 4 Ah at the same time. Yes, that probably wouldn't be a very clever or sensible idea, although I'm not convinced that it would necessarily do any harm. The tool would presumably stop working (satisfactorily or at all) once the 2Ah one was pretty discharged, wouldn't it?

 

[spile]

As has been repeatedly said, 'the general public' do not necessarily use, or even understand, technical definitions - and that has to be taken into account when attempting to communicate clearly with them.

Indeed and in many cases this isnt an issue. but loose/misuse terminology can can lead to significant misunderstanding and bad decisions.Clear communication requires translation of complex ideas without losing their essential meaning.

 

[spile]

Some will have opposite views on this.
For a start many batteries are now rated in Wh, does that alone not demonstrate a 1440Wh (120Ah in car battery terms) battery is more powerful than a 720Wh (60Ah in car battery terms) battery?

As an example (in very basic terms ingoring the methods of voltage drop used to establish capacity) the 12V 60Ah battery can supply say 3A or 36W for 20 hours but the more powerful 120Ah version can supply 6A/72W or twice the power for the same time.

If exactly the same techniqes and construction methods are used to make the above 60 & 120Ah car batteries then: using your description it's fair to say there will be twice the power and twice the capacity.... The two tend to go hand in hand for similar products.

Watt (W) is a unit of Power. Watt-hour (Wh) is a unit of Energy (Power X Time).
Increasing the size of a Lead-Acid battery increases both its capacity and its power doesn't mean those two properties are the same thing even though that internal resistance makes them appear that way.

We had a narrow boat with both a starter battery and a deep cycle battery. Both 12v and same capacity but both had very different designs because of their different roles.

 

[JohnW2]

Indeed and in many cases this isnt an issue. but loose/misuse terminology can can lead to significant misunderstanding and bad decisions.Clear communication requires translation of complex ideas without losing their essential meaning.

Exactly - and I would suggest that in most (maybe all) situations it is usually the person who knows the 'correct technical terminology' who needs to translate that into language understood by a member of the general public if/when one wishes to communicate with such a person (rather than the converse) - in other words, it is not usually the general public who should be expected to learn how to 'translate' the language they normally use into something 'more technically correct'.

At probably something like its 'worse', failure of the 'expert' to 'translate'could result in a statement such as:
"having inspected this toy imported from Asia, I can report that all of the touchable electrical parts are at low voltage" !!

 

[SUNRAY]

Watt (W) is a unit of Power. Watt-hour (Wh) is a unit of Energy (Power X Time).
Increasing the size of a Lead-Acid battery increases both its capacity and its power doesn't mean those two properties are the same thing even though that internal resistance makes them appear that way.

You obviously didn't read my reply

We had a narrow boat with both a starter battery and a deep cycle battery. Both 12v and same capacity but both had very different designs because of their different roles.

You obviously didn't read my reply

and why I mader such a statement




There is no point in mentioning different technologies when

 

[JohnW2]

On every decent cordless I’ve ever used they’re a physical gearbox; the drill makes the same noise at the same pitch when the trigger is fully squeezed but there is an obvious drive difference. There is also a heavy clunk when you operate the switch and if you can even operative it while the drill is running, a crunch and a change in the chuck speed but no pitch change from the motor. If it were electrical its effect would be very different

Interesting. My first reaction was to think that perhaps I haven't experienced any 'decent' ones. However, I'll have a play with what (probably 'non-decent') ones I have immediately to hand and will report back!

It seems that you are right, even in the case of 'non-decent' ones.

For a start, it occurred to me that these drills invariably have continuously-variable speed controlled (presumably electrically) by the trigger, so that it would make little sense for there also to be a 'switch' which did essentially the same.

I'm still a little surprised by what I've observed. The slide 'switches' on the couple of ('non-decent') ones I've looked at move very smoothly without any particular 'clunk', and that remains the case even if one operates the 'switch' whilst the drill is running (per trigger control) at its highest speed. It would have been nice if some of the cars I drove very many decades ago had 'synchromesh' that good However, as you say, when one operates the switch there is an immediate change in chuck speed, without any discernible change in the sound of the motor - so, as you say, seemingly a real 2-speed gearbox.

Does this mean, I wonder. that I have been doing things 'all wrong' for decades? As I wrote, as well as using the 'low speed' ("1") gearbox setting for drilling larger holes, I also generally use it for screwdriving. However, if it's a 2-speed gearbox, then this will presumably mean more torque at the lower 'speed' setting, which presumably increases the risk of cam-out of the screwdriver bit in the screw head (an only too common problem - at least for me ).

It seems that this may be today's example of "one leans something new every day!!

 

[robinbanks]

It seems that you are right

I’m not renown for the contra

presumably mean more torque at the lower 'speed' setting, which presumably increases the risk of cam-out of the screwdriver bit in the screw head (an only too common problem - at least for me ).

I find the opposite; driving screws at high speed, with the added pressure from your hand, exacerbates tiny oscillations in the setup with the effect that the screw/bit/chuck assembly wags around more and is more likely to slip apart

If you routinely experience cam out, ensure you’re driving using the bit appropriate for the screw; PZ bit in PZ screw (most modern wood screws), PH bits for PH screws(typically plasterboard screws and screws that hold assembly line assembled things like appliances, very occasionally furniture) and that the number matches (don’t drive a PZ3 screw with a PZ2 bit)
If all matches check that bit and screw head are in good, un-worn condition. After toiver driven a thousand screws and had the bit bounce round inside a few of them, chewing the head, you’ll have worn the edges off the bit’s drive flanges:

Thanks to some kind soul listing a used pz2 bit on eBay.. take a look at the left flange, where the edge is visibly worn away in the clockwise driving direction; this bit has bounced around inside more than one screw head during acres in, but not so taking them out (the edge of the right flange is on good condition)

Once your bit wears like this it will need greater pressure to prevent it slipping; it’s in its death throes and should be swapped because it will just chew more screws, especially if you drive it at a stretch of your arm or other poor angled position that means you can’t put much pressure on it

 

[JohnW2]

I’m not renown for the contra

I hope that's justified

I don't know about "renown" in my case, but all of us (particularly myself) are more than capable of being wrong - which is why, if you read through my posts in this forum and elsewhere, you will find countless occasions on which I've typed "... but I may be wrong" or suchlike. Indeed, unlike some, I rarely, if ever, 'assert' unless I am absolutely certain about something. Again, if you read my posts, you'll see that I generally write things like "it is my understanding that ...", "I believe that ....", "I think that ...." etc. (often followed by the "(but I may be wrong")", rather than 'asserting'.

I find the opposite; driving screws at high speed, with the added pressure from your hand, exacerbates tiny oscillations in the setup with the effect that the screw/bit/chuck assembly wags around more and is more likely to slip apart

Fair enough - but, in case it wasn't clear, I was not talking about 'driving screws at high (chuck) speed' but, rather 'driving screws with the drill set to its higher speed setting'. In either case I would control the chuck speed (by use of the trigger) to the same (usually pretty low) speed.

If you routinely experience cam out, ensure you’re driving using the bit appropriate for the screw; PZ bit in PZ screw (most modern wood screws), PH bits for PH screws .... and that the number matches (don’t drive a PZ3 screw with a PZ2 bit)

Yes, I learned all that very many years ago, and am always careful to use the correct type and size of bit.

If all matches check that bit and screw head are in good, un-worn condition. After toiver driven a thousand screws and had the bit bounce round inside a few of them, chewing the head, you’ll have worn the edges off the bit’s drive flanges:

I'm also very aware of that. I generally buy bits, usually 'good quality' ones (generally deWalt) in large batches, and change them very frequently, not the least because it's a bit of a 'vicious circle' - since 'camming out' is presumably one of the things that can cause damage to the bit (as well as to the screw head).

You may not agree, but I'm inclined to think that 'cross-head' screws (PZ, PH etc.) and, in fact, almost all heads other than 'slotted' ones (e.g. 'Torx etc.) are somewhat of a two-edged sword. When they (and the driver/bit) are intact, they are great, and offer many advantages over traditional slotted-head screws. However, once they become damaged (or covered in countless coats of paint over the years/decades, it's a different story. With slotted head ones, one can usually clean the paint out of the slot and effect 'repairs' to damaged ones (e.g. deepening the slot) but (at least, for me) it's much more difficult to remove a non-slotted screw whose head has been damaged or clogged up. If it's a reasonable size of screw, one can drill down the middle and then use a 'tap remover' (with LH thread) but if its a small screw, it's often the case that all one could do is the 'drill (or even 'grind') off the head' and hope there's enough shaft left to get a mole wrength onto, to unscrew it!