When you spend time in a hospital, it’s unlikely that batteries are one of the things that you spend time thinking about, but without them, you will find yourself facing a lot of barriers. Take a moment to think about the battery-run equipment that is used in a health care facility. From the heart monitors to the blood analyzers, operation-related equipment, thermometers and pumps, and even defibrillators, there are many devices which must run even during a power outage, and having battery backup for those things is vital – when you think about it, that’s a lot of SWL2500EFR batteries!
The U.S. market for medical devices alone is worth around $180 billion. This makes it the largest market in the world for such devices according to the 2017 Global Market for Medical Devices. Equipment manufacturers are constantly struggling with ways to provide portable battery-powered devices that are reliable and longlasting. Discharge profiles, chemistry, and the effects of ageing batteries are all things that the companies must try to understand and improve.
Battery Chemistry Issues
Ventilators, anaesthesia machines, and dialysis systems are usually powered by the AC supply, and the battery is a backup. The battery will receive a shallow discharge and then will recharge again. A sealed lead acid or valve-regulated lead acid battery has one key flaw. That is the rise in the internal resistance of the battery.
As internal resistance rises, there is an increase in the need for power. This causes a drop in voltage which can be problematic. One of the biggest mistakes that device manufacturers tend to make is to choose a battery that has an internal resistance unsuitable for the load.
After several charging sessions, the peak charging rate for a lithium-ion battery cell will start to decline. The cell undergoes some physical and chemical changes. It is important to charge batteries using the lowest current that the user is willing to tolerate, and to recharge it when the battery’s capacity has fallen to a level which means it is no longer useful.
Dialysis machines, for example, that move around with the user, should be recharged quickly because failure to do so may reduce the quality of care that the user receives. Other machines may trickle charge if they are not required to be mobile.
Large hospitals can purchase as much as 97,000 batteries to run their machines, and those batteries will need to be disposed of. Nickel, cadmium, lead, and mercury can be dangerous, and hospitals need to dispose of batteries safely to prevent those heavy metals leaching out into the environment.
Disposing of Batteries Safely
There is an ongoing campaign to see hospitals implement recycling programs for batteries and electronics. This will help the long-term sustainability of hospitals and our planet. Educating staff on how to safely handle and decommission batteries is important, and battery maintenance is something that should be taught to biomedical engineer technicians so that they can ensure that batteries last a long time while still providing good patient care.
Battery Recycling Should be a Priority
Patterns in battery purchasing should be analysed in hospitals as a matter of course, and the pounds of batteries recycled should be considered. The hazardous waste vendors who work with hospitals are in a good position to take batteries away for safe recycling, and organisations such as the Rechargeable Battery Recycling Corporation can help with this too, ensuring that in the long term hospitals are taking care of the environment, and not releasing toxic materials into the earth.