markz said:
Are you powering the controller straight from the generator or just charging up a spare battery?
No, no spare batteries (yet). In my case: charger powered from generator, output of charger connected to charging port of BMS, discharging port of BMS goes to controller power input. Generator runs as i ride. Since all power FETs in BMS are in open state during ride - controller draws power from generator and battery simultaneously. When controller draws less, than current of a charger - battery gets charged, when controller draws more than charger can give - battery discharges.
markz said:
Whats the size of the generator you have in the picture? I only went back a half dozen or show posts but you did mention it again but nothing specific.
I use an identical twin of that Chinese generator:
https://www.alibaba.com/product-detail/Smart-Power-price-mini-generator_60802434435.html
I didn't buy it from Aliexpress though, i've bought a local one branded as "Patriot 1000i". I think, you can find something similar on local market with convenient warranty terms and modest price.
It's really less than 10 kilos of weight, with size of a 20-25 liter jerry can (user manual says it's 395х209х355 millimeters, that's about right). The only drawback of this machine - is power of only 0.7 kW, which is not enough to compensate power consumption of a moped running at 50 km/h. Hence my future switch to more powerful model.
markz said:
Looking at the chargers input requirements for a given charger. Say you were lucky enough to find a Meanwell charger that uses 120Vac and 10A of power to spit out 48Vdc and 25A, generator would need to be 1200W, so up size it a bit to 1400W loaded running wattage.
That calculations of yours is about right, IMO. The only thing is confusing marking of generator - manufacturers like to rate it for it's peak power output, not constant one. So choose carefully, odds are, your model would be with badge of "something 2000 watts", when it's really constant output power would be around 1300-1500 W you needed. I'm personally would go for a converted telecom PSUs as charger, the ones with current and voltage adjustion - then you can fine-tune power you drawing from generator, so it would run with optimal load.