-----Original Message----- From: Duane Attaway

On Wed, 15 Dec 2004, djgoku wrote:

... APC is evil and sets their float voltages too high. Its a great business model.

Marine batteries are about $60 for the 125 Ah sizes at Walmart. Pretty big bang for the buck. That's about 20 times more power than the original UPS battery.

You should be able to modify the float voltage by adding resistance to the circuit. I have yet to make my homemade UPS. What do you recommend for an enclosure? I think it's safe to assume that marine/ motorcycle batteries are to big to fit in the APC battery slot. I was thinking about using sheet metal cut and bent. Something like:

+-+ +-+ <-- screw tabs +-+-+------+-+-+ | | | | | | v +---+--------------+----+-+ | | | | | | | inside | | | | | | | | | | | | | +---+-+-+------+-+-+----+-+ +-+ +-+

+--------------+ | | | | +-+--------------+ | | | | | inside | | | | | | | +-+--------------+

^ |______ screw tab