APC ups schematic and block diagram, charge contoller info, and blah

[CustomIngenuity]

This post is to share one of my latest projects and consolidate web resources concerning APC UPSs and open source charge contollers.

The setup is as follows:
MPPT75HV from Intronics Power (charge controller)
2 - Trojan ??ah 6v
1 - Trojan ??ah 12v
1- 2500W (24v) modified sinewave inverter 
24v system with taps at 6v and a 12v
I like to run as many items as I can on dc, ie. telecoms gear, monitors, lights, with the hopes of having "all" digital devices on dc. The rest would be ran off the inverter. Big dream I know, however a dream nonetheless!

Until my PV modules get replaced I would like to still be able to run off of DC. This would require a mains to DC conversion on quite a scale.

There are literally a ton of big UPSs waiting to be had for cheap or free. And of course I have several laying around, why not start there. At first the idea of using the charging output to charge the batteries sounded good: "fail".
Then using a APC su2200net (48v) inverter I ran the charging leads into my charge controller. That was a very cool experiment. With the controller set for a 24v system the input current would steadily increase while the voltage decreased. At some point around 20amps or the inverter would reset and do it all over again in about 1min intervals. Boring! Setting the charge controller for a 48v system became interesting very quickly. The inverter would not cycle like it did previously. The experiment ended when I blew the 30amp fuse on the output to the batteries. The inverter was a beast and I think it had more to go.

Initially I wanted to build a large battery charger. While doable, it would be a steep learning curve. But why build one when I already have a nice battery charger? I could skip all the charge functions and feed filtered dc into my charge controller. It is rated for 80vdc in and 75A out. If the su2200 could perform at such a high output I think the transformers are up to my challenge.  Pair the 2 transformers with 8x  60 - 100 amp  diodes @ $4 a piece . (I don not remember the specs, they are used in high current alternators) Also include large heat sinks and I think I am on to something.

There are not many hard specs in this post because I have only begun to gather ideas and have not spec out the transformers yet. Nor have I calculated the power dissipation.

Learning is the goal of most of my projects with occasional functionality. It is cheaper than the university. Information about UPSs specific APC is a bit sparse on the net and I wanted to post my findings.  There are other bits as well. I hope this post is of use to someone.
Thank you Dave for your explanations of the three types of UPSs   
Side note: Many thanks to all the individuals who have posted about Tek scopes and scopes in general. I have gleaned much information from the posts.

Cool story! Nice insite to APC
http://techno-fandom.org/~hobbit/power/dumbups

This was the piece of the puzzle I had been missing
(Russian)   http://www.mirpu.ru/ups/84-shemups/146-su1000.html 
(English)    http://translate.google.com/translate?ie=UTF8&prev=_t&tl=en&u=http://www.mirpu.ru/ups/84-shemups/146-su1000.html&sandbox=0&usg=ALkJrhjIZbzVykfPo9yAfD4IaDu0bi1hTw

su2200 schematic
(comparing the su220 schematic to to the layout of the su1000 they are very similar. At first glance it even seems the control panels are the same. Maybe APC used this setup or minor variations or it for many models?)
http://www.electronica-pt.com/esquema/func-startdown/11818/

Other schematics/manuals
http://www.electronica-pt.com/esquema

Transformer info
http://cr4.globalspec.com/thread/70133/UPS-Transformer-Specifications-Power-Supply

APC cable pinouts
http://pinouts.ru/ups/

Charge controller diagrams, open source projects with code
http://www.redrok.com/electron.htm#charger
http://www.freechargecontroller.org/
http://www.re-innovation.co.uk/web12/index.php/en/projects/open-charge-regulator/161-open-design-charge-regulator-project