Is it bad idea to solder few 18650s together or do i really need to buy a spot welder for my project?
Is it bad idea to solder few 18650s together or do i really need to buy a spot welder for my project?
Is it bad idea to solder few 18650s together or do i really need to buy a spot welder for my project?
i've done it before with success
a couple years ago i refurbished a couple ryobi tool batteries with new cells, and i just soldered the tabs to the cells, and they're still working great
it's fine
if the pack gets hot enough to weaken a good solder joint, interrupting the circuit is a feature
Just be quick. Don't soak heat into the battery.
Do they need to be structurally fixed to one another?
I've just dabbed solder beads on the ends of batteries before to make them long enough fit "specialized" battery slots (i.e. my electric razer).
One thought that occurs to me now is what about taking a metal snap fastener (for clothes) and soldering the ends on each battery?
Gotta be careful about the selection of metal for the fastener, though!
well how about you simply work out the cross sectional area of each joint and the energy required for each process and the heat dissipation curves for each method and you can tell us?
do you need to buy a spot welder or could you just buy a car battery from an auto store and return it the same day just say its the wrong size and say you need a size they dont stock. couple dollars for a high current solenoid and maybe some kind of footswitch if you aren't strong enought to pull the probes off while its flowing
Lightly scrape the surface, put some flux and then solder a bead of solder to the battery ends.
With a powerful enough iron it will adhere perfectly before the rest of the battery has time to heat up.
people only use spot welders because they're faster in a production line environment. soldering them one by one works fine, just don't be a dipstick and leave the iron on for a long time.
set your iron on it's highest temperature and get in and out.
max out your iron
pre-tin the wire/strip and your tip
Should be able to dab it on for 2 seconds and get a good enough bond, if you can't get it bonding in 5 seconds, get a bigger iron/Thicker tip with more mass.
450°C is good enough? is a K tip good for this?
how about you try it and find out?
So, I've also been wondering about this question for a while. A lot of sources say you shouldn't solder batteries because they might over-heat. Has anyone actually had this happen? What actually does happen if you were to over-heat them? Do they 'explode'? Or does it simply reduce their effectiveness?
lowers their life span and capacity much quicker if they're allowed to get really hot.
if you let it get hot enough you'll probably melt something and things that aren't supposed to touch will touch and you get a thermal runaway reaction and all the pixies escape through the magic smoke phenomenon.
Thanks. That makes a lot of sense.