Portable power generator

I'm not a camping fan, but this year it's gonna happen. Anyone got an experience of using a portable power generator to recharge their board while away from power sources? We will have the car with us at least. I was thinking one of these:

Spec is 40000mAh/146Wh, I think that means it would just charge the GT once. Anyone with more battery noodle than me have an idea cheers?

 

Will work fine. I used my Server APC battery backup once for shits and giggles. I got about 30% charge onto my board before it ran out of juice.

Just make sure it can handle the high wattage of your 4amp charger. If you are using the regular charger you will be fine

 

Inverter
2000w/4000w car charger converter power inverter DC 12v to AC 240v with USB camp | eBay

Should allow for a 3.5a fast charger
I wouldn’t think you would need a pure sine wave but check that out first. Pure sine wave inverters are more expensive