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Comment by BenjiWiebe | Hacker News Reader

Are you sure about the few minutes part? The standby generators I've seen take seconds to go from off to full load. We have an 80kw model, but I've also seen videos of load tests of much larger generators and they also take only seconds to go to full load.

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It might depend on when the backup system was built. No company updates their system every year.

A few minutes seems correct for one place I worked.

This was back in the 90's, before UPS technology got really interesting. Our system was two large rooms with racks and racks and racks of car batteries wired together. When the power went out, the batteries took over until the diesel generator could come online.

I saw it work during several hurricanes and other flood events.

I always found the idea of running an entire building off of car batteries amusing. The engineers didn't share my mirth.

Was a generator technician before I got into programming. Even the 2 megawatt systems could start up and take full load in 10-20 seconds. It sounds basically like starting your car with your foot on the gas.

The "when" shouldn't really matter- Diesel engines aren't a new thing. Warming them up isn't really a thing either- they'll have electric warmers hooked up to the building power to keep them ready to go.

Lead acid batteries in that form factor were the staple for many UPS systems, and the thing most people didn't really appreciate was how expensive they were to maintain. If you didn't do regular maintenance, you'd find out that one of the cells in one of the batts was dead causing the whole thing to be unable to deliver power at precisely the worst time. Financially strapped companies cut maintenance contracts at the first sign of trouble.

Edit to add: I was at a place that took over a company that had one of these. With all of the dead batteries, it was just a really really large inverter taking the 3-phase AC to DC back to AC with a really nice and clean sine wave.

Lead acid batteries are still industry standard in many applications where you are OK with doing regular maintenance and you just need them to work, full stop. I think you'd be surprised how much of your power generation infrustructure, for example, has a 125VDC battery system for blackouts.

I think it depends on the type of generator. I know one datacenter I worked with had turbine generators that took a few minutes to get spun up. They were started and spun up by essentially a truck engine. Those generators were quite old, though.

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