Although medical cart batteries are designed to fulfill the same functions, there are various types, sizes, chemistries, and features to consider. Understanding the strengths and weaknesses of each battery chemistry type is critical when shopping for battery-powered mobile medical carts.
Here is a detailed look at medical cart battery features and essential questions to ask to find the right technology for your needs.
What Battery Chemistry Does it Employ?
When choosing battery technology for your battery-powered medical carts, it is critical to understand the underlying chemistry because it determines many critical factors: natural battery capacity, charge time, and heat under load.
Three types of battery chemistry are available on the market: lead-acid batteries, lithium-ion batteries, and lithium-iron-phosphate (LiFePO4) batteries.
Lead-Acid
Lead-acid batteries are power sources employing the same principles as car batteries. Some of the earliest powered medical carts were derived from non-powered carts and employed car batteries as their onboard power source. The underlying technology is stable, mature, well-documented, and is known for being long-lasting.
However, a lead-acid battery is typically heavy and difficult to replace. The charging time is approximately as long as the total capacity, and damaged units can be hazardous (e.g., sulfuric acid leaks).
Lithium-ion
Rechargeable Lithium-ion battery technology is a popular alternative to lead-acid, employing the same principles as rechargeable batteries in common non-medical devices (portable medical devices, smartphones, laptops, commercial batteries, etc.)
A rechargeable lithium-ion battery is typically lightweight and easy to handle, and modern versions support hot-swapping and fast charging. Many point-of-care workstation models employ this battery technology to keep weight and costs down.
However, their capacity is limited, and repeated use significantly reduces their lifespan. Additionally, they are known to reach high temperatures under load, presenting a risk of overheating or starting lithium battery fires.
LiFe Battery Technology
Lithium-iron-phosphate (LiFePO4) is a newer battery technology for medical devices and patient care carts, combining the advantages of lead-acid and lithium-ion batteries into the same custom battery pack.
The iron-phosphate chemistry in LiFe batteries grants them a longer battery run-time than the typical lithium battery, but without most of its disadvantages. For instance, LiFe batteries do not get overly hot even under maximum load, preventing overheating of equipment. Additionally, they have shorter recharge times and support hot-swapping, making them ideal for a healthcare facility.
What is the Battery’s Capacity?
Virtually every medical cart battery available today has enough power to supply all devices typically found on medical carts and workstations on wheels (e.g., computers, laptops, emergency devices on crash carts, barcode scanners, etc.). However, one aspect that can vary significantly is battery capacity.
Here are a few questions to ask yourself when looking at battery products for your mobile medical carts on wheels:
- What is the average autonomy of the battery?
- Is the autonomy enough to last a shift?
- Can you extend the total autonomy with multi-battery systems?
- Are hot-swap batteries available?
- How often will you need to replace the battery?
Although modern versions of all three battery chemistries support hot-swapping, LiFe batteries offer the best capacity. A lead-acid battery lasts 8 to 9 hours on average, whereas a lithium-ion battery lasts 4 to 6 hours, and a LiFe battery can run for up to 10 hours.
How Heavy is a Single Battery?
Battery-powered carts are quite heavy because they are stocked with computers, medical equipment, medication, and other supplies. The battery adds to this weight.
Consequently, it is crucial to ensure that the battery you choose is not too heavy for the cart, especially if you want each cart to support multiple batteries (e.g., hot-swapping, extending the total onboard capacity).
Over 50% of the weight in a lead-acid battery is the lead elements it contains, resulting in a high unit weight. The average weight of a single lead-acid battery for medical devices approaches that of a car battery (25 to 30 lbs. depending on the model).
Although hot-swappable batteries are available in lead-acid, they weigh down the cart heavily, making them challenging to handle and creating many potential safety risks.
Lithium-ion batteries are known for being relatively lightweight. Models designed for medical carts typically weigh about half as much as lead-acid equivalents (between 12 and 15 lbs) and can be recharged to full capacity in 2 to 3 hours.
However, you must contrast this low weight with their relatively low capacity; the battery run-time on the heaviest models rarely exceeds 6 hours.
LiFePO4 custom battery packs employ power cells with extra-high energy density (up to 90 watt-hours per kilogram). Although each unit features an autonomy of up to 10 hours, each battery weighs no more than 8.1 lbs., making multi-battery setups relatively lightweight and highly convenient. A dual-battery setup with LiFe batteries is enough to last well over an entire shift in a typical hospital environment.
Additional Battery Technologies to Look For
Having long-lasting batteries at your disposal is meaningless without useful battery management features. Such features can help you better integrate battery charging and replacement into your personnel’s protocols, helping create more efficient workflows.
- Easy hot-swappable batteries: Removing and inserting batteries should be quick, easy, and require no particular expertise, enabling medical personnel to swap spent or low batteries for fresh ones at dedicated battery charger locations. LiFe batteries support hot-swapping and multi-battery setups, allowing a properly managed healthcare computer cart to receive continuous power without interruptions.
- Unambiguous state of charge indicators: Most medical battery systems employ icons or percentage values to represent the remaining battery time. A more readable alternative is to display the remaining battery time in hours and minutes using large, easy-to-read letters.
- Low battery alerts: Nursing staff must make the most of the available battery power even with the best technology. With LiFe batteries, an alert appears when the remaining battery charge level falls to 20 minutes or less, providing enough time to replace it without wastage and extending the battery replacement intervals to the maximum possible length.
Take Advantage of Scott-Clark’s Flexible Mobile Cart Power Technology
Having worked with medical carts for years, Scott-Clark Medical has recognized the inconveniences caused by the typical batteries available in the medical industry. Our answer to these challenges is the Flexible Mobile Cart Power Technology, our patented power supply system for medical carts.
Each FMCPT battery can provide battery-powered mobile medical carts with up to 10 hours of power. Additionally, they support hot-swapping and come with SOCI II power indicators to alert nurses and prevent unexpected power interruptions.