Comments on: UPS Battery Series & Parallel Question ? http://www.batterybackupguide.com/blog/ups-battery-series-parallel-question/ Mon, 21 May 2012 21:11:10 +0000 http://wordpress.org/?v=2.7 hourly 1 By: cmos solutions http://www.batterybackupguide.com/blog/ups-battery-series-parallel-question/comment-page-1/#comment-1066 cmos solutions Sat, 07 Feb 2009 12:01:37 +0000 http://www.batterybackupguide.com/blog/ups-battery-series-parallel-question/#comment-1066 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 ... 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 …

]]> By: joe s http://www.batterybackupguide.com/blog/ups-battery-series-parallel-question/comment-page-1/#comment-1065 joe s Thu, 05 Feb 2009 09:46:08 +0000 http://www.batterybackupguide.com/blog/ups-battery-series-parallel-question/#comment-1065 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. 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.

]]> By: billrussell42 http://www.batterybackupguide.com/blog/ups-battery-series-parallel-question/comment-page-1/#comment-1064 billrussell42 Mon, 02 Feb 2009 06:31:18 +0000 http://www.batterybackupguide.com/blog/ups-battery-series-parallel-question/#comment-1064 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. . 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.

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