When a client is looking for a UPS to safeguard his load with a determined back-up time, it always comes to the an end decision, to buy a small UPS with an additional Battery Pack or to just buy a bigger UPS. Because of the price difference (UPS + BP > Bigger UPS) the customer normally decides to pay less for a bigger UPS then to pay more and have the ideal solution of a UPS with an additional BP. The UPS with a Battery Pack may look like the expensive option, but bigger UPS have a higher power consumption, meaning that over its lifetime having a bigger UPS will result in a higher electric bill.