The Benefit of High Rate Batteries VS Conventional
We are often asked why we recommend C&D UPS MRX or MRXF (the F indicates a front terminal version) series batteries for UPS systems especially where high current short time use is required or where space limitations require a high energy density battery to maximise UPS runtime availability.
The reason is simple – C&D have developed and supply one of the best batteries specially designed for the UPS industry that specifically meets these requirements.
For example, if you look at the C&D UPS12 410 MRXF battery it is rated at 109Ah, but this is not a good indication of how it performs in a UPS application.
Almost all general purpose battery Ah Ratings are at their 10 Hour Discharge rate (C10) or sometimes their 20-hour discharge rate (C20), which is a fairly irrelevant rating for UPS applications. When used with a UPS the full discharge rating will normally be between 5-60 Minutes, this is a wildly different number from C10 or C20.
Comparing the C&D battery to an alternative general purpose battery of similar Ah rating and physical dimensions we can use the C&D UPS12 410 MRXF battery which will deliver 415 Watts Per Cell under a 15 Minute Discharge to 1.65 Volts Per Cell and our own Vision general purpose front terminal battery the CT12-105x which has a C10 rating of 105Ah which is close on Ah rating to the UPS12-410 MRXF, the actual 15 Minute Discharge to 1.65 Volts per Cell is 318 Watts Per Cell.
When compared at a 10 Minute discharge to 1.65V per cell the UPS12 410 MRXF hits 520W and the Vision CT12-105x only 376W – this is a 38% difference and is typical of other general purpose batteries available on the market compared to the C&D MRX/MRXF product.
Obviously, this gives the C&D UPS12 xxx MRXF battery a big advantage in UPS applications, impacting greater available runtime from the battery or that fewer batteries are required as there is better energy density which equates in less cost, or that we can use a smaller C&D MRX series battery to achieve the same result.
In addition, the C&D MRX and MRXF series have been enhanced and engineered to be able to handle the high currents involved in short duration discharge. This is also a benefit when the battery is used over longer discharge periods as the internal engineering of the C&D battery is more robust to handle the higher currents and temperature effects of short runtime use.