Originally posted by Dave Tolle (RRT, RCP) ret:
Portable ventilators are designed to be able to meet some high workoads if needed. Users with more normal lungs use less power than those with stiff lungs or higher minute volumes. Each vent will have a DC circuit breaker rated in amps. That value is the highest DC current draw allowed for that unit before the safety breaker trips. On some vents you can measure the DC amp used in a particular patients case by placing an ameter (multimeter, digital or analogue) in line while a battery is in use. The power draw will vary being nominal during exhalation and maximal at peak pressure. With a little math you will derive the average amp draw for that utilization. Deep cycle batteries are all rated in amp hours. Divide the average amp requirement of the patient into the amp hour rating of the battery and you'll get hours of available use time on a fully charged battery. This will give some guidelines for battery use periods,etc.... There should always be a wide safety margin of power or additional DC sources available if need requires. Also
solar panel put out DC power and can be used to recharge batteries or directly supply DC power to ventilators as long as the power output ratings are within user needs and maximum safety (actually what you do is put batteries in-line with them to act as big capacitors).
