The "E-Trucker" Hailong Battery is small but proving to be a functional choice.
It fits nicely on the rear rack and doesn't appear to be an obvious battery.
More like a rear rack bag.
The charger is small and very lightweight. The charger doesn't pull over 100w when charging SO the Small Jackery 160 can be used to charge the e-bike battery ! This is a big win for touring. The small Jackery less than 4 lbs, very useful and can be solar charged. The Shimano Steps battery/Charger could not be charged with the Jackery 160 (It required a larger Jackery 300).
Below is a picture of it charging the e-bike battery.
Below is a picture of the Jackery 160 Charging the E-Bike battery while also being charge via a solar panel.