BILL BAUER wrote in a message to Roy J. Tellason:
> I'd like to get a setup going here which would do that.  I thought about
> adding more capacity to this UPS I have here,  but asking them at the
> factory about it they nixed the idea,  told me it'd burn up the inverter.
> They said "some" of their models would deal with more battery,  but it'd
> cost me maybe $1000 to find out.  I don't think I'm gonna do that,
> though...   
 BB> More battery hooked in parallel isn't going to change a 
 BB> stinking thing except how long the load (computer, monitor, 
 BB> whatever) will work. 
The impression I got was that this might be the problem, that the ratings of 
the parts in the inverter was such that if you ran them for too long they'd 
burn out.  Or something like that.
 BB> The extra batteries can't supply more voltage than the computer 
 BB> is designed to handle and they won't supply more amps than the 
 BB> computer is capable of handling except in the case where the 
 BB> UPS might short out. You'd get some real fire going that way 
 BB> and each bank should have a fuse in it which is rated at the 
 BB> max current that the computer can handle so that does not 
 BB> happen. The only real problem that would occur by using extra 
 BB> batteries would come if you had a power outage that lasted for 
 BB> more than about 8 hours (guestimated.) Then you are going to be 
 BB> looking at an extremely long recharge time which might be 
 BB> unacceptable. 
I was even prepared to make alternative arrangements to charge the extra 
batteries,  if I needed to.  Heaven knows I've got enough of that sort of 
hardware around here.
 BB> In the event of an extended power outage, I would want to cut 
 BB> the external batteries out of the circuit when the power comes 
 BB> back on and recharge by other means. Since I am looking at 
 BB> recharging 8 12 volt batteries (8 6v in series equals 4 12 
 BB> volts in series) in series (with 4 12 volt batteries in series) 
 BB> that gives me an effective total of 8 12 volt batteries in 
 BB> series. Since thats about 2 batteries short, I would simply add 
 BB> two more 12 volters in series with those and rig up one of my 
 BB> homebrew battery chargers to the whole mess and plug them into 
 BB> the wall and let them charge for about 10 to 18 hours if 
 BB> necessary. Then they would be ready to go for the next 
 BB> emergency.
 BB>  
 BB> Don't see any way for any problems to develop that way. I have 
 BB> been doing it that way for a couple of years now with never a 
 BB> problem of any kind.
I may have to call them again,  or write to them,  and see if I can get 
something a little more detailed out of them with regard to just how I can 
deal with this...
One thing I hadn't gotten around to was deciding what sort of connector to 
use for the additional batteries.  Anything you favor along those lines?  
They sure don't give you a whole lot of room to work with,  there.
--- 
---------------