To the point. First the bad. Absolutely cannot charge the battery while riding.Also, AC charging the Jackery is slow 84 w consistently. Like charging with 2 a charger. The good news is the Jackery 500 will charge the Vado at over 170 w + continuously about twice the rate it takes the Jackery to charge from AC at 84 watts consistently. I pulled over at starbucks after riding 19.5 miles carrying 40 + pound load on my rack, at an average rate of 16 MPH with 53 % battery remaining (1157 elevation gain) at 9 am. It took approximately one hour to charge the Vado from Jackery to 90%, with Jackery showing 55 % battery remaining. After riding another 15.66 miles battery dropped from 90 to 43 %. Charged Vado back up with remaining power from Jackery to 80%. I did this with MC default settings.35/100, 75/100,100,100 the entire way. With just the Vado battery same route/distance. I'll have 33%-52% battery remaining at 15/35,25,55,70/75. Depending how much I pedal unassisted.
I think one 500 w (closer to 553 w actual capacity) battery pack is a great alternative to buying a second battery at less than half the price of a spare 600 w battery. Basically, you'll be paying less than 1 dollar a watt. $450.00 total taxes included. I don't know why the output rate is twice the input. I think above 170 w consistently is considered fast charging. About the same with the 4a unit, maybe faster. My other Jackery unit is fully charged in my other Pannier unused. I haven't tried the Rockpal 100 w Solar panel yet but if you buy 2 80 w Rockpals and run them parellel you can charge the Jackery at 100 w consistently with clear sky. So, I believe 2 100 w parellel would be more. They come with the adapter to run parellel if you want. Those are my findings so far. I highly recommend based on Jackery's output ability. Not to mention its portability and usefulness to other appliances.