Hey Scotty, what is an affordable good brand car battery jump starter to buy? I need one to have in my vehicle during the winter season. Thank you.
I have a Hulkman jump starter recommended by Scotty in a past video and it works well. Also Project Farm has tested quite a few:
https://www.youtube.com/watch?v=bMXyoIBJyJA
https://www.youtube.com/watch?v=jlK7UWHD3sY
Be aware that storing a jump starter in frigid temperatures will affect its battery output.
I’ve got a few of whatever brand Costco has.
I have two that are just jump starters, that can also be used to charge phones.
And I got another one that also doubles as an air compressor.
@kaizen have you used one to jump start a car?
Yes, all of them worked great. Used them on X5 when I had it, my Accord and my Prius.
Also doubles up as a phone charger.
I like the Super Capacitor ones.
Scotty recommends this one
https://www.youtube.com/watch?v=ZMfo4mk3eIw
For what it's worth Scotty mentions jump starters in a recent video about winter preparation:
https://www.youtube.com/watch?v=Tk1RrBPGGng&t=261s
In the video description he recommends 3 models:
Super capacitor jump starter: https://amzn.to/3i7SH5D
Mid-grade jump starter: http://amzn.to/2nrc6qR
Best jump starter: https://amzn.to/4c1O9JI
I have a Noco Boost Plus GB40 (Scotty's "Mid-grade" model) and it works pretty well but I found it will not start a car with a completely dead battery.
I also have a Hulkman jump starter (Scotty's "Best"), but the smaller "8.5/Alpha 85" model rather than the big 10.0 that Scotty shows. (I don't need to start V8 diesels.) I have found the Hulkman 8.5 is able to start a car with a dead-as-a-doornail battery.
I've never used the super capacitor type of booster so cannot comment on those.

@chucktobias thanks for the detailed review
My jump starter is a GooLoo GP4000 bought on sale for about $80 on Amazon. It's been a good unit, even used it on my garden tractor.
The super capacitor starters are not affected by cold weather. That's important in regions with lower temps. If I lived in a colder area (state), I get a super capacitor.
https://www.amazon.com/dp/B09HJH1S41
I bought this Auxito for 50 bucks back in November. I have used it 3 times so far and it has worked perfectly. It has a very bright LED light which you can change to a flashing red light, plus it is magnetic. So far so good. FWIW, the NOCO ones have a very good reputation, I used one in the past and it worked fine (but they cost more).
Good luck.