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Simple DC UPS

Posted: Fri Jun 01, 2012 3:05 am
by nutsone
'A simple DC UPS' (NV, Jan '11) tells me I should use an alkaline backup battery. Why can't I use a rechargeable? I would like to trickle charge a battery in this circuit.

Thanks

Re: Simple DC UPS

Posted: Mon Jun 04, 2012 7:50 pm
by ringo47stars
I don't have that month so I don't have the article but I can say that typically an UPS battery is just a back-up for emergencies so the battery is not used very much. It sounds like you want to use it for a charger and switch from the outlet to the battery often. If the battery is not used much then a cheap alkaline could be used but to use the battery often would require a rechargable one.

Re: Simple DC UPS

Posted: Thu Jun 07, 2012 11:07 am
by dacflyer
Hmmm, most UPS's i know of use a Gel-Cell rechargable battery...

Re: Simple DC UPS

Posted: Mon Jun 11, 2012 4:30 pm
by ringo47stars
I meant the type of ups that has the battery disconnected from the circuit until needed would have a cheap and maybe rechargeable battery in it because the battery wouldn't get used much. If you connect a battery in parallel with a power source with a diode between the +'s then reverse leakage of the diode would have to be minimal. Then if the power source is a solar panel and the output gets low the battery supplements the output so that might indicate the battery in that type of circuit supplements the output. Maybe try putting a large capacitor in the circuit to have some power from the capacitor until the battery is connected. The circuit in the article looks like it is missing a relay to connect the battery if the power fails but it might work with the non-rechargeable alkaline or lithium ones they suggested. I got a copy of the article just to see what it was about.