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I have seen various takes on the requirements to provision backup power for the Dialysis Cycler (and most of it out in left field.) The purpose of this blog post is to provide my input to this concept (BS/MSEE Purdue University.) The image below from the Cycler Manual shows the max power at USA’s nominal 115vac public power to be 480 watts. Keep in mind that this is MAXIMUM.

What does it take to feed a 480-watt load for say 11 hours (my Cycler times have been in general between 10 hours 25 minutes and 10 hours 50 minutes?) In this case, I am going to address battery backup in the form of a UPS (Uninterruptable Power Supply.) We need to feed a 480 watt load with nominally 115 vac for 11 hours. These are our parameters for calculating the number of and Amp-Hour requirements for batteries for our UPS, as well as the Invertor to invert 12 volt direct current from the battery(ies) to 115 vac.

Luckily for us, there are several USP Calculators available on the web. I have linked the one we will be using. We have to use iteration (try values until desired results are obtained) in the panel.

In the UPS panel, I inputted our power of 480 watts, available battery amp-hours of 200, and number of 200 amp-hour batteries at 3 to obtain the 11 hours 32 minutes runtime which would cover our requirements. From this we have calculated that we require three, 12-volt 200 amp-hour batteries. Turning to our universal off the shelf place, Amazon, we find that Renogy makes such a battery for $359.99 each, or about $1180.00 for the three.

The inverter of at least 600-watt capacity is also sourced from Amazon. A 600-Watt Pure Sine Wave Inverter goes for $78.70.

We need one more component to kluge together a UPS for our Cycler, a trickle charger to keep the batteries up. Amazon has one of these fitting the bill (10-Amp Car Battery Charger, 12V and 24V Smart Fully Automatic Battery Charger Maintainer Trickle Charger w/ Temperature Compensation for Car Truck Motorcycle Lawn Mower Boat Marine Lead Acid Batteries) for less than $27.00.

So, for $1180 + $79 + 27 = $1286 plus tax etc. you can build a healthy UPS that will run your Cycler for a complete Dialysis. You will also have to provide some battery interconnecting cables. Or you can buy a small gas generator such as a Honda 1000, or a new Ford truck with EV and plug into it, or……? You are in “charge.”