Medistrom battery backup

[parkerdt]

Then my small generator must not have sufficient regulation. Its sine wave varies enough so it won't charge my UPS. Perhaps you could PM me the small generator you have in mind? Or even share it will all of us as a review?

thanks,
Dave

[GWild]

Not having the pair in front of me to scope out this is all hypothetical: I'd suspect your genset frequency is off or the UPS is old school diode bridge taking power only at the peaks (not PF corrected). Do you own a Kill-A-Watt meter? A $30 or so investment that can be pretty useful around the house. It would tell you a bit about what's going on.

And - to correct my knee jerk post - a modified sine wave inverter is usually around 30% distortion. Also - keep in mind that line power isn't that good, especially if you have a lot of motors around you: the crest factor can make the waveform look pretty ugly, line THD of 5% or more isn't unheard of.

[parkerdt]

We also no nothing about the output waveform of the Medistrom, so no one knows if it is better than the latest APC Back-UPS or not. This thread is full of opinion and some math, but unfortunately short on observed and measured facts. I just don't want to spend $350 + to be a test subject, nor do I want the many 5 second outages we have to continue to stop my machine. Almost makes me want to turn on autostart, at least for the interim.

Dave

[GWild]

It appears to be a simple DC-in DC-out battery pack. But an RS S1 560P sans heaters should run off it for a full night without too much trouble - assuming you are in the 10-12cm category. And if all you are worried about is short outages, it seems ideal... plus no switch-over time that might upset the xPAP.

[parkerdt]

Thanks, but I have no interest in running a RS S1 560P for any length of time at all since I don't have one. And I do have the ResMed white paper sitting in front of me. it says I'll get the same amount of time out of this battery as I would out of an APC 1500VA ups. Except it is more than twice as expensive.

As I said, I have no interest in running without my humidifier and heated hose. It's an absolute requirement for me to get any sleep whatsoever. Otherwise, I sleep better without my machine. Since most people seem to use and prefer their humidifiers, based on the thread on this board, it seems pointless to talk about battery run time without the use of one, a hypothetical situation for most users.

Dave

It appears to be a simple DC-in DC-out battery pack. But an RS S1 560P sans heaters should run off it for a full night without too much trouble - assuming you are in the 10-12cm category. And if all you are worried about is short outages, it seems ideal... plus no switch-over time that might upset the xPAP.

[Terry]

Then my small generator must not have sufficient regulation. Its sine wave varies enough so it won't charge my UPS. Perhaps you could PM me the small generator you have in mind? Or even share it will all of us as a review?

thanks,
Dave

The Honda EU series works perfectly and produces a clean sine wave.

You can hardly hear the 1,000w model.

[parkerdt]

Great! $1 per watt. I'll get a 17kW whole house unit with a transfer switch before I pay Honda's prices. Those will run my AC as well.

But thanks for the reference. I was afraid that kind of unit was what you all were talking about. Less than 8 hours fuel capacity is an issue as well.

Those are fine units for tailgating, though.

Dave