Go on YouTube and look for a young content creator named Will Prowse.  He has many videos about solar generators and modern battery technology.  And quite unbiased in his critiques.
Anthony

Sent from Yahoo Mail for iPhone

On Thursday, November 18, 2021, 22:43, David McNeely <davmcneely40@GMAIL.COM> wrote:

Almost Friday, and actually Vanagon related, in a way.

Do any of you use "power banks" when traveling and camping in your
Vanagons?  I am talking about 2 different animals here.  First, those
small, rechargeable batteries sold mainly to folks who just can't stand to
be without phone power for even minutes.  I have a different need.  My wife
is diabetic, uses an insulin pump, and has to recharge that pump every 2-3
days.  One of those small batteries should be useful to extend our stays
out and about, if we can get one that has enough power to charge the pump
multiple times.  Lots are advertised and promoted, but most carry totally
unknown "brand names."  Any recommendations?

Second, big power banks, the kind supposed to replace generators for power
outages and for camping.  Any experience with those?  Again, most that I
see carry unknown "brands."

mcneely