larry@kitty.UUCP (Larry Lippman) (05/07/89)
In article <17996@cup.portal.com>, ISW@cup.portal.com (Isaac S Wingfield) writes: > I'll bet that if you used a lead-acid gel cell or some > Ni-Cads in your telephone, you could charge them all the > time the 'phone was on hook, and have plenty of "free energy" > during off-hook use. The maximum amount of current which one can draw from a telephone line while on-hook without running the risk of telephone line trouble is about 1 milliampere (this actually exceeds usual loop leakage specifications by a factor of two, but I'll be generous). (.001 ampere) X (50 volts) X (8760 hours) = 438 watt-hours per year At typical electric utility rates of 7 cents/KWH, this power is worth about 3 cents. Assuming that you can save 3 cents per year, let's do the ROI calculations for a 4 ampere-hour 48-volt battery string; this will give you the capability of saving up all your energy for a 2-hour consumption spree once per year. Using 4 Globe JC1240-1 12-volt 4-AH gel cells @ $ 34.00 will cost you $ 136.00. Neglecting the cost of money, changes in future energy costs and useful life of the batteries, the batteries should pay for themselves by the year 6522. :-) <> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp. <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231, 716/773-1700 {att|hplabs|utzoo}!/ <> FAX: 716/741-9635, 716/773-2488 "Have you hugged your cat today?"