cheap (but safe) 1 kWh power station?

[Whitenuckler]

I had an APC brand UPS that refused to work on our old Coleman generator. It worked fine on the Yamaha inverter replacement.

Did you happen to measure the output of the old Coleman? Sometimes the voltage regulator boards can go bad. Also, the frequency can be off too if the engine is not regulating the proper RPM.
The inverter ones have far more regulators, so they they maintain 60Hz and 115VAC. I have an inverter type that I use(d) for camping with 30A 120V, and run it on propane. Then some monster house 240V 30A that weighs a ton. It's pure steel and copper, no electronics.

 

[begreen]

It was a new generator. The voltage was ok, around 120vac but I didn't have anything to measure frequency. Regular stuff like refrigeration and lights didn't mind it, but the UPS wanted cleaner power.

 

[sloeffle]

My CFL bulbs flicker with my generator, that's why I know it's not producing clean power. I checked the frequency and it wasn't horrible but it wasn't as good as grid power. My generator isn't grounded either, and I read that can help. If the generator has 30 - 40 hours on it, I'd be surprised. It's a Champion 3500W gas generator.

 

[Burnin Since 1991]

I've been researching this vary topic. It's my understanding that the newer style Backups / UPS need pure sine wave in to work properly. I have a 4500/3500 watt generator that's about 14 years old. It has worked well, but I think I have been fortunate. I'm adding a few battery backups with UPS mode to prevent the damage from having the power pulled out from some of my various devices. I'm also getting a 4000/3000 watt inverter/ generator to power those backups. The fate of the old 4500/3500 is undetermined at this point.

Just make sure to size the units so that they can handle the required output. I sized mine a bit bigger which means I only have to run the inv/gen to charge them once or twice a day.

 

[Whitenuckler]

I've been researching this vary topic. It's my understanding that the newer style Backups / UPS need pure sine wave in to work properly. I have a 4500/3500 watt generator that's about 14 years old. It has worked well, but I think I have been fortunate. I'm adding a few battery backups with UPS mode to prevent the damage from having the power pulled out from some of my various devices. I'm also getting a 4000/3000 watt inverter/ generator to power those backups. The fate of the old 4500/3500 is undetermined at this point.

Just make sure to size the units so that they can handle the required output. I sized mine a bit bigger which means I only have to run the inv/gen to charge them once or twice a day.

Many devices actually take the AC and rectify it into DC, as all electronic's use DC. I would think a good modified sine wave would be OK for them. The pure sine wave inverters are best for things that have AC motors. AC motors don't work as well on modified square wave because of the extra harmonics. Now that they have these brushless DC type motors (like HVAC blowers with variable speed) I don't think it matters anymore for that motor type. A true sine wave output device should still be the best for all applications. I agree it's best to run a generator for a short time feeding a large charger. My pellet stove has a 35A battery charger and a 80AH AGM.