I'm building an autonomous boat (which needs to get me a bottle of fine whisky from Scotland) for which I want to build a battery pack. The boat is currently powered by a cheap Li-ion battery pack, but I want to build my own battery pack so that I can better determine the shape of it to fit it in the boat
After reading around I decided I want to build a LiFePo4 battery pack, mainly because it's more chemically stable and heavier (I actually need the weight). The battery format 18650 seems to be the most standard, so it seems logical to go for that. As far as I understand I need a spot welder to connect the batteries together. A spot welder seems really expensive though and I don't really need it for anything else.
While searching I also found these batteries with tabs on the poles (see image below). My question is whether these can be used to build a battery pack without the need for a spot welder? Maybe I can simply connect them by soldering wires on to them?
The battery will only be charged very slowly by day, and be discharged relatively slowly by night (maybe 12V*1.4Amps=16.8 Watts or so discharge), so I don't think the wiring will become very hot.
Are there any downsides to not using a spotwelder? Is there any serious drop in performance? Or any other dangers I'm unaware of? All tips are welcome!