Having 2 Batteries For A Battery Backups System Work Better Than 1?

[montecarlo1987]

Hello. I have a question. Regarding Battery Backup UPS systems, having a dual or 2 batteries incorporated into the unit better than having just one battery? They are usually 12 volts each.
Under typical conditions, regardless of the wattage needed; would the runtime (running due to loss of power) be increased or not? ...but how? Is this significant increased in runtime or not? It is truly worth having a second LEAD battery backup in your unit?
Please reply.
Thank you!

 

[LiquidSnak]

Having a second battery will increase either voltage or capacity, depending on how they are wired. Hooked up in series will increase the voltage, so 12V > 24V system. Parallel wiring will increase the capacity and thus run-time.

 

[Keiichi25]

As Liquidsnak mentioned, yes, more batteries (Provided the UPS supports it) means longer uptime during an outage. Remember, depending on how much load you put onto your UPS will also affect the amount of time you have left on your battery, but increasing the capacity based on the actual unit will help as well.

Most personal UPSes are in the 350 to 1500 range. The 1500s will give you the most uptime depending on how much you load down the battery backup sockets, at least more than the 350s. I recommend you look at the chart for your UPS as well. APC UPS tend to show both their usual run time and runtime with the additional battery back unit.

Edit -
I do want to note, however, financially wise, having a second battery is pointless if you only need the UPS to supply power just long enough to shut down. In some situations, you really don't want to spend the money on an extra battery UNLESS you ABSOLUTELY need to keep whatever it is you are running for as long as possible. In disaster situations, I would NOT recommend trying to keep your computer on as long as you can. If you absolutely, positively need to keep systems up for as long as you can, you will be looking at a more enterprise level UPS, like a 2200+ with larger battery packs from a business/enterprise (I can't afford to be down) reason.

Remember, there will be times power will go out in an area, sometimes, longer than the 10 to 15 minutes you are hoping to be down. Personal level UPS devices are not ideal for "I need to be up all the time." run levels, hence my follow up here. Adding a second battery for UPS should be on the provision that you need to extend it several more minutes, but not because you can't afford the computer to be down at all.

 

[montecarlo1987]

Thank you for the replies.