Scooter Soldering Kit Battery

I wanna know if I can hot wire my scooter battery to a regular
12v/60w soldering iron to do local soldering repairs without going to the
other fuel/chemical bonding methods for safety ????

I know most soldering kits, you buy or build, usually require a
standard wall socket 120v/60w soldering iron and some 4AA batteries....

So I was wondering what would happen if I used a 12volt SLA 8 amp
battery, since the wall outlet is a about 90watts and the 12volt SLA battery
is also some 96 watts although it drops quickly to an easy 11 volts because
of a burned cell I'm guessing....

The math is there but some other factor is missing, I can't see the
power of a 12volt SLA battery to a mere 4 AAs ...........has anybody ever
tried this with a regular soldering iron for outdoor use???

 

Why not? No more current will pass through the heating coil than the
resistance of said coil allows to pass.

If you're worried about damaging the soldering iron, put a 10 amp fuse
in the input wiring. 10 amps should be twice the normal maximum
current draw of the 12 volt iron. (1)

The AA batteries would provide half an amp of current to the heating
coil of the soldering iron, but wouldn't have the ampere hour capacity
to keep supplying the
1/2 an amp the iron draws.

If your wall outlet has a 30 amp breaker or fuse, it will supply 3600
watts, not 90 watts.

Your battery may be old and could be dehydrated or has sulfated
plates.

Your fully charged 8 ampere hour battery should provide 8 amperes to a
load for
one hour without the voltage dropping below 12 volts. If it quickly
drops to 11 volts under load, it's not fully charged.

The resting voltage of a fully charged SLA battery half an hour after
charging should be 12.8 volts.

You can find battery state of charge charts online which will tell you
what the state of charge of a lead acid battery is, according to
resting voltage.

The missing factor in your understanding seems to be the concept of
*ampere hour capacity*.

No, I never tried that, but...

Work out the Ohm's law for your 120 volt soldering iron, or measure
the resistance of the coil and you'll see how many amps it draws from
a 12 volt battery.

The heating coil doesn't know what the source of power is, it just
heats up according to the current it receives.

(1) You might want to research the coefficient of resistance of
nichrome wire to see what the resistance is when the wire gets hot
enough to melt solder.

 

Yes. You should have stopped right there........

.......as the rest of your post pretty much makes no sense.

Also, for about $5 from Harbor Freight or JC Whitney or similar you can get
a pencil size butane torch.

 

Hey Bob, IIRC, a typical 1.5 V AA battery has a capacity of about 500 milli-amp-hours, so four of them could theoretically supply half an amp at 6 volts for an hour, ie., about 3 watts for an hour, or 60 watts for 1/20 hour = 5 minutes, if my arithmetic is right. Five minutes would be barely enough time to raise the element's temperature to operating range. A new 10-amp-hour 12V scoot or bike battery, at least theoretically, would have about forty times the capacity ((12/6) * (10 / 0.5)), say a few hours. However, with an older battery, I'd guess that after fifteen or twenty minutes, there might not be enough capacity left to start your scoot (the SLA battery's internal resistance becomes significant - IIRC your 400cc scoot's starter motor probably draws 40 or 50 amps, if it is worn, that could double). Also, SLA batteries lose some of their recharging capacity if they are drained below roughly half of their capacity. I think it wouldn't be a good idea to solder connect
ions on the same scoot with the engine running, ie., charging, in fact it is risky to do any electrical work on the scoot with the negative battery cable attached, nor would I use an accessory socket without checking the wiring diagram first - you might find yourself blowing the fuse for the socket. I guess it would work okay and not jeopardize starting if you used a surplus battery. Other factors are the wire size, I'd guess you wouldn't want to use anything smaller than 18 gauge, preferably 14 gauge, also an inline fuse in case the iron has a short in it. Also, just because an iron is rated for 60 watts, doesn't mean it won't draw double that while warming up.

I like the little butane irons, for the small amount of soldering I do, the fuel cost doesn't matter and I have no risk of stranding myself after draining the scoot battery too much.

 

I really wouldn't. A scooter battery is so small it'll flatten quickly
(unless you keep it attached to a charger while soldering). Just buy a
proper mains current soldering iron. It's not like they're expensive.

That's the simple answer.

 

I used to work with an aircraft electrician who had to go out and do
emergency repairs on helicopters under combat conditions in Viet Nam.

He had a soldering iron which was heated by chemical reactions while
he crouched in rice paddies and bullets whizzed around.

While most electrical connections on aircraft are crimp type
connections, and the same is true of motorcycle connections, I always
cut off "iffy" terminals, strip and tin the wires and solder them
together.

Recalling my Air Force tech school education, I calculated that a 12
volt 60 watt
heating element is going to have 2.4 ohms of resistance and draw 5
amperes.

A 120 volt 60 watt element is going to have 240 ohms of resistance and
draw
0.5 amps of current.

It seems like fully charged 8 ampere hour battery in good condition
should be able to keep that iron hot for 16 hours without the voltage
dropping below 12 volts.

But, what do I know? After all, I am senile, suffering from syphilis,
Lyme disease, and I'm an alcoholic drug addict, according to some NG
users...

 

And this relates to scooters... how, exactly?

 

Home from "work" already?

Couldn't you have just stopped at your local pub and tossed back a
pint and
played a few rounds of darts with your friends.

Or are you Sutton's local "Billy No Mates"?

 

Yup. Unlike you, I have a job. You got fired, didn't you?

 

Mark Olson wrote:
....

I know Bob and if he's still living in that colourful part of town I remember, he must do his own maintenance on the street without access to household power. (Heh, heh, I'm lucky, relatively speaking, my trailer has a power outlet, only problem is in winter when I have to remember to turn off various appliances inside because of the whopping 30 amp service in the park!)

 

Yes, but Bob's original post asked about using a 12V/60 watt iron! The resistance of that would be around 2.4 ohms.

(I've seen ones advertised that have a cigarette lighter plug. IIRC they were about 30 watts.)

 

Now I can see my conceptual error. I was *ass*uming that the 120 volt
soldering iron would always dissipate 60 watts.

 

Well, cock-a-doodle-doo! and hooray for Neil Murray, he hasn't been
sacked recently!

 

God judges me and Jesus forgives me, though. How can *you* carry a
grudge against the judged and forgiven?

 

In that case a fully charged 8 ampere hour battery in good condition
will power his 12 volt 60 watt soldering iron for 8/5 = 1.6 hours
before the voltage drops below 12 volts.

 

The pencil size butane torch I have works very well - unfortunately the
catalysing solder tip that came with it is about as much use as a chocolate
teapot!

 

I used to work with an aircraft electrician who had to go out and do
emergency repairs on helicopters under combat conditions in Viet Nam.

He had a soldering iron which was heated by chemical reactions while
he crouched in rice paddies and bullets whizzed around.

While most electrical connections on aircraft are crimp type
connections, and the same is true of motorcycle connections, I always
cut off "iffy" terminals, strip and tin the wires and solder them
together.

Recalling my Air Force tech school education, I calculated that a 12
volt 60 watt
heating element is going to have 2.4 ohms of resistance and draw 5
amperes.

A 120 volt 60 watt element is going to have 240 ohms of resistance and
draw
0.5 amps of current.

It seems like fully charged 8 ampere hour battery in good condition
should be able to keep that iron hot for 16 hours without the voltage
dropping below 12 volts.

 

They don't know me at all, they just read what they want into my
screeds and throw labels around.

 

Finally, someone with some actual electrical training. I was laughing my
A** off while reading the "theories" about how a 12VDC source would take the
place of 120VAC.

BTW, 120VAC is the RMS (Root Mean Square) voltage. The wiring for an AC
soldering iron is completely different from a DC soldering iron. To get
120VAC RMS voltage out of the household outlet, the AC generator must swing
from 169.7 volts positive, through zero and then to 169.7 volts negative
(and thus the reason it is called a sine wave). The 120 volts (average)
measured is calculated from the SIN 45 degrees which happens to be 0.707
times the peak voltage of 169.7 VAC.

Not to mention that Ohms is calculated completely different for an AC device
than for a DC device. In a DC device, Ohms is a linear calculation, not so
for AC. In DC, Ohms is RESISTANCE, for AC circuits, it is IMPEDANCE.

Wouldn't surprise me to find out the AC soldering iron electrical coil was
toasted when the voltage was applied across the two terminals.

Sounds like not only was the "math" not there, but a little education wasn't
around either. LOL

Have a great day!
--
Steve Spence
Independent AMSOIL Dealer
AMSOIL - The "Once A Year" Oil Change
Unemployed Car Guy - Trying to Earn A Living
35 Years of GM Parts Experience
http://synthetic-oil-tech.com/1690163

 

OK, so we are left with two options:
1) Practice soldering with a bare butane flame. The pencil torches can be
adjusted (after a short warm-up) to a flame small enough to do the
job.......but that IS an acquired skill.
OR
2) Spend a few extra bucks and get a "real" butane soldering pencil. I have
one and it works very good......."catalyzing" tip and all!