alternative power supply for imac

[dbruiger]

Hi,
I want to create an alternative power supply for my imac G4, for extended power outages or off the grid use. I have a 12-volt 8D commercial battery and a Xantrex "XPower1000" (1000watts) inverter, purchased from Canadian Tire. The inverter's output is described on the packaging and in the manual as a "modified sine wave" but the manual cautions that the output is "non-sinusoidal". It also cautions that "some chargers for small rechargeable batteries" can be damaged by connection to this device. I have run my imac without noticeable problem with power supplied by a generator with built-in sinusoidal inverter, connected to an APC UPS device. I notice that the latter also says right on it that its output is "non-sinusoidal". I need to know if there is any problem with the battery plus inverter plus UPS plus imac configuration. Thanks so much.
Dan Bruiger <dbruiger@telus.net>

 

[simbalala]

I&#8217;m not sure you&#8217;re going to find an easy answer to that question. The iMac uses a switching power supply so a non sine input might be OK but I couldn&#8217;t say for sure. One power supply design might be happy with it while another might go nuts or overheat.

 

[SatCure]

As the UPS has batteries inside, all you need to do is ensure that they have adequate capacity for the time you need to run without mains power. You might even be able to connect your 12 volt battery across them (with a suitable diode to prevent reverse current from flowing). Driving a UPS with another battery system is very inefficient and not very sensible. Too much to go wrong.