crimp terminals

[Fred]

Hi,

I am trying to replace a couple of sub-c nicads. Something that should be so simple is not going smoothly!

Is there a trick to soldering the tags of two cells together? It has taken me ages and the result looks untidy. What trick am I missing?

I now find that the remaining tags are too wide for the spade terminals, so I was going to change the terminals for wider ones. I've not crimped before so I am unsure what size spade terminals to buy.

In tool station they describe them as 1.5, 2.5, and 6mm. I presume this means they take 1.5mm^2, 2.5mm^2, 6mm^2 cable rather than being the actual size of the terminal?

In cpc they list the spades as being IIRC 2.8mm and 4mm. I think the ones I have are 3mm (2.8?) and the ones I need are 4mm. So far so good, but they then say something about being 0.8mm. Is this the thickness? Why don't they mention the length or are all spade terminals a standard length?

TIA

[dom]

Obviously I can't see your soldering from here, but the essentials are suitable materials (e.g. copper and tinned surfaces take solder well, steel doesn't), clean surfaces (no oxides), clean soldering iron (scrape off any blackened flux & when hot - wipe the iron frequently on a damp sponge), HOT iron and BIG ENOUGH FOR THE JOB (a little hobby iron for component soldering may struggle), and suitably sized solder for the job (which should contain flux). Technique, get the iron hot - solder should melt onto it in less than a second, get a little melted surface onto the iron to act as the contact point, firmly make contact with what you want to solder until you have wet solder on the surface

- then add what solder you need for the job.

Overall a slightly overpowered soldering iron is better than an underpowered one - which may tend to cook everything whilst you wait and wait for the joint to get hot enough.

1.5, 2.5, and 6mm is probably the wire size (x-sectional area), as you suspected.

Can't help you with the terminal size. Try swinging by a halfords (where they'll charge you quids for a pack of 3 or summat) - but at least you can compare what you need with what they have.

[newshound]

I agree, battery tabs are a pig to solder, but I don't know what material they are. Nickel plated perhaps? Advice about a big hot iron is correct, though.

[Dave Plowman (News)]

Tin them both, clamp together with a crock clip, and wave a small (jeweller's) blowlamp over them.

[Ronald Raygun]

You tin each tag on its own first (i.e. melt solder onto them). Then you position the two cells so that the tags overlap, apply a blast of heat, and let the two blobs flow together.

Chances are that this positioning is the critical part of the operation and requires more hands than you have, or is awkward because of the way the cells need to fit together when done.

If so, it may be better not to solder the tags together, but to take a short length of wire and solder one end of it to each tag.

[Fred]

I wonder if this was my problem. It's an antex but I can't remember what power it is. I've always been a bit unsure about soldering iron power ratings, a quick look on the internet shows antex make irons from 12w to 100w. Is there a guide that to do job x, you need y watts?

I am guessing mine might be the 25w model.

Thanks.

[Fred]

IIRC I wound a bit of wire around the tags to help hold them together because I needed three hands and also it seemed to help the solder "hold".

Thanks.

[Dave Plowman (News)]

Most decent electronics irons these days are low voltage (24 volt) 50 watt thermostatically controlled. 50 watts will cope with most things you're likely to find round electronics like even large terminals. But without thermostatic control would get too hot.

The 'standard' small Antex non thermostatic mains is 15 watts. This is fine for PCB soldering. With a large enough bit and left to pre-heat or recover it could do bigger one offs. An 'instant heat' induction 150 watt type can be worth having for the odd larger job - although I prefer a small jeweller's blowlamp for this mostly these days.

[Fred]

Thanks. You've answered my next question which was going to be about thermostatic control. I see a lot of irons do not have it but your reply suggests that there is a real advantage to having it.

Could be. I am sure it ends in a 5. I did look but I've forgotten again! I'm pretty sure it does not have thermostatic control. It was bought cheaply from maplin in the days when maplin was good and the catalogue was like a data sheet compendium.

larger job - although I prefer a

Instant heat, no waiting, that sounds good. The blowlamp sounds as though you could destroy things if you weren't careful/don't know what you are doing.

TIA

[Terry Casey]

There is a difference which distinguishes the 12 & 15 watt irons from the rest of the range. Look here:

should clinch it.

[Andy Dingley]

Thermostatic irons can use 50W elements with plenty of "oomph". Non- thermostatic irons were limited to half or a third of this.

[Dave Plowman (News)]

Not actually instant, but faster to warm up than a conventional iron of that sort of size. But only really of use for quick jobs. If you were soldering large areas of say tinplate or brass, a conventional one would be better.

True, but that can apply to an iron too.

[dennis]

I have seen some RF heated irons, they appeared to have some sort of waveguide to send power to the tip. They were a few hundred watts (or so i was told) so would have heated tin plate I would think. I never used one so I don't know what they were like to use.