Anybody know about Uninterruptible Power Supplies (UPS boards)?

Thread Starter


Joined Nov 13, 2012
I'm trying to charge a 24V battery, which would discharge to an LED and buzzer just in case a 120Vac power supply is cut-off. So this battery is not in use probably for a long time, hopefully 5 or more years. Thing is, a battery seller told me that it's better to use a UPS board instead of a charger to discourage back-current just in case the battery is in use.

1. What exactly does a UPS board do (in my specific case)?
2. Any websites (instead of wikipedia) that explain this?

after-question: What is the best battery to use in my case that it might not be used for a long time?


Joined Sep 9, 2010
I think you have a thread on this already, why are you starting another?

As I said there before, you don't need an UPS to light an LED and a buzzer.


Joined Oct 31, 2012
the best batteries would be deep-cycle marine batteries (they are usually 12v, so 2 of them in series) - you should be able to just use a diode to prevent any back-feed from the output side of your assembly (although I suspect this is likely over-kill for your scenario, they are generally the best for UPS use)

UPS have more complicated circuits to monitor the battery charge and stop charging the battery once charged (important for non-lead batteries), and skip the battery when there is no need to use it (input power is clean/working) and send that directly to the output, and then switch over quickly if/when the input power fails, and also usually some sort of computer connection to let a computer know if/when to shutdown

you should be able to use a diode to prevent any back-feed to the battery