UPS Battery Series & Parallel Question ?
kings asked:
I was searching for a UPS for my computer and found one which says 1000W / 2000VA, DC 24V
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I was searching for a UPS for my computer and found one which says 1000W / 2000VA, DC 24V
This means connecting 2 x 12V batteries in series. My question is don’t UPS usually have batteries connected in parallel rather than series ?
Does connecting it in series or parallel affect the backup time ?
What are the advantages and disadvantaged of either setup (regarding UPS battery) ?
Thanks
If I do get it I’ll have to buy the batteries as a separate buy.
and connect them up myself. So how does connecting in series affect (if at all ) backup time compare to parallel and does connecting in series or parallel reveal the type or quality of the UPS ?
February 2nd, 2009 at 1:31 am
Does it matter? It’s all internal to the UPS box, it doesn’t really matter how they are connected, as long as it works as specified.
Are you sure? I never saw a UPS where you buy the batteries separately. The internal circuits are very tightly tied to the battery and it’s capacity.
but, series or parallel, backup time and discharge time are the same. But if the UPS requires 24 volts, you have no choice, it needs two 12 volt batteries in series, or one 24 volt battery.
series, higher voltage, lower current, means the wires can be smaller and the power transistors can be of lower power rating, and there is less heat dissipated.
.
February 5th, 2009 at 4:46 am
it has to be two 12v in series to get 24v
if they were connected in parallel, there would only be 12 volts,
but twice the capacity.
February 7th, 2009 at 7:01 am
You have to use the voltage specified. For two equivalent supplies, with one using 12V in and the other 24V in, they would provide almost identical run times with the same pair of batteries. The difference is subtle. If the voltage is too low, the currents are high and thicker conductors have to be used. 12V is convenient because of the availability of marine batteries (I use two in series). At the other extreme, really high voltage requires more insulation and has electrocution concerns. The electrical codes change as the voltage goes up. Higher capacity systems typically use higher voltage. Some use 48V or even 96V …