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Thread ID: 146069	2018-04-16 01:40:00	UPS Help	ManUFan (7602)	PC World Chat

Post ID	Timestamp	Content	User
1448496	2018-04-16 01:40:00	Hi All I know absolutely nothing about UPS's (Uninterruptible Power Supplies). We have a need for one in the office to run a 14v DC radio for up to 12 hours (min) when we have a power cut. Does anyone have any recommendations? Watts? VA? Cheers	ManUFan (7602)
1448497	2018-04-16 02:28:00	You don't need bugger all to run a radio but then 12 hours lifts it a bit, why not just get a battery operated Radio and save the hassle, probably cheaper than a UPS anyway. Then keep a spare set of batteries handy. Also UPSes have an annoying habit of beeping during an outage, can be very irritating and not all models allow it to be turned off or might need a pc connected to do it. Look on the back of the radio and see if it lists the wattage or amperage, if it just list amps multiply it by the voltage to get the watts. Or get a watt meter and plug it into that and take a reading So if the Radio uses 10 watts (for example) x 12 hours = 120 Watt hours. Next you need to find run time figures for the UPS on load and try and convert that to watt hours. Most of them specify wattage somewhere and something like say a 20 minute run time at 50% load. Or you can just use the battery capacity of the UPS as a rough guide - smaller ones often use a 12V 7AH battery which is 84 watt hours in theory but you need to halve that in practice (fully flattening a lead acid battery damages it and the UPS will not allow that)	dugimodo (138)
1448498	2018-04-16 22:36:00	Does anyone have any recommendations? Watts? VA? Cheers Without knowing how many amps that radio draws, anything is just a wild guess. Radio could be 1/4A , it could be 20A . Is it just a small radio with 1 small speaker, or is it driving several speakers at reasonable volume (like a PA) I would just buy a car battery and wire it up to that when the power goes out . A car batt would give much longer runtime than an average UPS Would need to keep the car batt charged though, and replace it every 2 or 3 years & do a test run to see how long it lasts on batt power. Even a UPS needs its internal batt replaced every 3 years or so. That usually never happens, so often those UPS's do nothing when the power is cut (as its batt is bad) Honestly, 12hours is beyond what most UPS's are intended for Get a small petrol powered generator .	1101 (13337)
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