Looking for LOW cost UPS battery back-up for XXV to cover short power outages (30-60 mins) To use when not home and stove running on manual (so the igniter wont be needed) Looking for a computer type...not marine battery. Anybody using something that fits the bill? Does it even exist?

) which is why they work okay with the UPS power. The real problem is that you can fairly easily cut off the corners of the square, but it's really hard to get the sloped line of change in voltage over time through the 0 point without actually being a pure sine wave so there really isn't a modified wave that has a flat spot at 0 that looks almost like the sloping change thru 0 that the pure sine wave has. That's why a DC source with a pure sine wave is more expensive than one with either a square or modified waveform.