Guest Post by Alex of High Tech Battery Solutions:
A UPS, or uninterruptible power supply, is an essential tool to protect your computer or other electronic devices from a sudden power failure or electrical spike. A single surge in electricity could instantly fry your computer’s motherboard or wreck your mobile phone as it charges. A UPS unit is designed to regulate the flow of electricity, monitoring it so that the electrical charge that reaches your plugged devices is at a constant rate. The electricity from the wall could fluctuate from time to time but with a UPS you’re devices will receive a consistent flow that is stable and safe.
Another key feature of a UPS is that it uses a battery or flywheel the moment that the main electrical source is cut off; for example, during a short black-out. The battery does not usually last long but it will be enough to either hook up your computers and the UPS to a secondary power source like a generator or will give you enough time to shut them down. Some people like to abuse this feature and think that daisy chaining UPS units is a smart move. Here is a set of reasons why you shouldn’t use the daisy chaining set-up and why it is a bad idea.
Why Daisy-Chaining is a Bad Concept
Daisy chaining is when you plug one UPS to the wall and then another UPS to the first unit. You then plug your computer or other electrical device to the second UPS unit. Some people like to keep going and add a third UPS or fourth UPS to the chain, thinking that they’ll be able to optimize the electrical regulating feature. One main reason why people do this is to get more time when the lights go out. The truth is, none of this works. Consider the following:
- The very moment the main power source dies and the first UPS unit flips to its battery unit, any UPS unit plugged into it will also flip to its battery unit. This is because the UPS units will immediately recognize that the electrical flow is not sufficient. So no matter how many units you chain together, you’re still going to get the very same limited amount of minutes to shut down your computer.
- You do not get additional power protection. If, in any case, a surge occurs and is strong enough to blow off the first UPS, that unit will switch to its battery. As discussed above, when this happens, the second unit will simply revert to its battery. The purpose of the UPS is to take the blow of any electrical fluctuation to give you time to shut down your gear or move to a secondary power source. They are not a source of power by themselves.
- By daisy chaining you are actually increasing the risk of overloading. The number of receptacles is indeed increased as you add more units to the chain but the Watt capacity will remain the same. As you hook more units, more watts per second can severely increase and cause the first unit to blow. This goes back to the first problem as all of the units switch back to their battery.
Alex is a technology researcher for High Tech Battery Solutions.


