My 12v heated gloves pull, at most, 2 amps (22 watts at 12v). Your 7v gloves… maybe 3-4 amps total. You are going to need about 2x 3000mah cells per hour. Im guessing that you might not run them on high… and maybe that turns into 2x3000mah per two or three hours. This is really simple to build and test…
Yes, I think it is simple to build and test. Unfortunately I don’t have the tools to make the battery pack myself that’s why I am researching around on where to get one. From what I understand so far a 3S1P (with 18500 or 18650 cells) together with a BMS circuit board that can balance the cells and a single DC female plug (1.35x3.5mm) would be plug and play solution for the pair of gloves that I have.
By the way, which gloves do you have?
Maybe you can just add step-up constant voltage converter to existing battery pack. Something like this (you can probably find smaller one), note this one is rated for 5A input, don’t boost to high, with 5Ohm load you should be good to about 11-12V (~5V from battery at the end of discharge minus some conversion losses)
You could adjust output voltage so you could use all 4 settings.
Off course runtime will be shorter but for long trips you can make external battery pack.
You could replace current 18650 with higher capacity but I believe it means building new pack as well.
For 3 18500, how they need to be arranged? Side by side?
Don’t know where you are, in US batteryspace.com has 18500 you want and they also have protection circuits, some with balancing (prefferable) - this one would fit nicely 3 18mm cells next to each other.
If you don’t have spot welder you can solder wires to batteries. You need strong solder iron, preferably with flat tip. Pre-solder wires, prepare battery, sand or scratch soldering spots really well, use good flux and solder quickly (you can also use low temperature solder to mitigate need for heat). If it does not take in few seconds stop, wait to let it cool, clean battery and try again. If you use PCM with balancing solder its wire to power wire before soldering it to battery so you don’t need to solder twice, twist them well so they don’t come apart while soldering.
The fully charged pack 3S1P would not be 11.1 it would be 3 x 4.2 or 12.6v. Another option would be to connect to the bike power system, then install a small regulator that you can set to the exact optimal voltage for the gloves…