Power conditioner plugged into computer battery

Please note that the APC unit provides a pure sinewave - as opposed to square wave power. Sinewave is what you need - computers don't care, and it is more expensive to produce sinewave power.

Secondly if you search the Forums you will see that almost all UPS, isolation transformers and the like limit current.

As Mr Hosehead suggests, it may be that once the UPS reaches full charge it will simply pass current straight through - there are only two ways to verify that, either measure it yourself or talk to the manufacturer. Since that would increase the cost and complexity of the unit with no benefits for its target market, my experience suggests that its unlikely.

The one way I know how to do it for sure is to use a 2,000-3,500w sinewave inverter tied to a large 12v battery bank. This type of unit which is designed for off-grid and marine applications, has a very fast switchover from the AC mains to the DC banks. It is also large, heavy and relatively expensive.

Finally I have compared the APC to both Equitech and BPT - the APC product is unique in that it is the only audio/video product that I am aware of that has a battery back-up. (This includes Running Springs, Chang, Gray etc)

Your engineering premise is fine - you just won't find what you are looking for at a low price point.

What I see from the Forum search is that people attempt to just use the computer UPS as a replacement for a separate power conditioner. That's not what I would like to do.

I'll be curious on what Mr_Hosehead means by these "caveats" must be there in order for an amp to dispense high current spikes. Would an amp be able to help itself for a long enough time thus sustaining such spike before it must be fed by high-current electricity?

Ckorody, would you comment about the additional circuitry complication that APC most likely won't do. Are you saying that there will always be a current limit even when the battery is charged up? In other word, it's cheaper to have the battery acting as a capacitor to the wall outlet voltage, as well as acting as the voltage source to all these outlets connecting to it. Are you saying that circuit design to have the charged battery become an open circuit, thus having to re-route these battery outlets elsewhere when the battery is charged up is more expensive? If so, it's interesting that APC and other computer UPS companies uses terms like "switch over" to the battery when there is an outage. Whereas in reality, the battery, half or fully charged, is always acting as the voltage source to its outlets. Then separately we have the scenario of an aged battery that is never fully charged thus the current leak.

I am not an EE - most of what I know about this stuff I learned working power issues on my sailboat. Inverters, batteries, alternators and 110. It is an unholy brew.

I understand what you are trying to do. I believe APC has done it for you.

BUT If you would rather roll your own (heck that is half the fun) then I suggest you just hook it up and see what happens.

Your comment that you can't power up your whole system without blowing the UPS suggests that the only thing you can do is to get a much bigger UPS - in the 2-3K watts range as you might find in corporate server environment. Perhaps the larger reserves will also help with any potential current limiting.

Please keep in mind that you are getting into the land of batteries - lots of juice costs lots of money, takes lots of space, maintenance etc. I am looking at the APC site and to get to 3375W they are using 208 in. The unit - without shipping or install is $3,350... Typical back-up time at full load is 6.4 minutes (no typo six point four).

http://www.apc.com/resource/include/techspec_index.cfm

One could come to the conclusion that the reason this product doesn't exist is because there is no real return on investment. Frankly it would be a lot less expensive and considerably more sonically effective to just run a couple of dedicated 20amp lines to your listening area.

Well, thank you for the comments, but the answer to APC S15 is a no. So far, it does not seem as if anybody had serious comparison between APC and the heavy weight audiophile conditioners such as PS Audio, Audio Power, Shunyata, etc. The existing reviews on the internet tend toward peace of mind and security, as opposed to music quality. Even Stereophile didn't focus on sound performance. Incidentally, security and integrity is what the computer industry expects from surge protector/UPS equipment. So something does not add up. The best I heard was about video quality improvement, and that is not enough a basis to judge music performance, especially when we are talking about upper division stereo separates. APC is well recognized in the computer world. Yet with severely limited review on the audio side, I am not about to spend that kind of money on a rather unknown piece of equipment.

You know - think this through - nobody makes what you are looking for...