If your facility or business uses mobile computer carts, you know that one of the most challenging aspects of managing this equipment is power and battery system management.
Mobile computer cart systems, such as medical carts used for patient care, or Computer-On-Wheels (COWs) for warehouse management, are among the most valuable tools for increasing productivity.
However, several factors can negate this productivity almost entirely, such as inefficient battery technology, improper power management, or human error.
Learning your power system’s characteristics and capabilities allows you to understand your battery power needs and consumption, reduce downtime, and preserve work efficiency.
How to Read Battery Characteristics
Batteries for mobile computer carts possess four essential characteristics: Battery chemistry, battery capacity, charge rate, and cycle life.
The term refers to the chemical elements employed in the battery cells’ construction. Some types are more efficient than others; it is essential to recognize and select the most efficient battery types for your mobile computer carts.
One of the most common types is Lithium-ion batteries (Li-ion), frequently employed in mobile device batteries, such as smartphones and laptops.
Lithium-ion batteries are compact and easy to use but tend not to possess the cycle life required for long-lasting, heavy daily usage. They are also relatively expensive and subject to aging even when not in use, resulting in frequent and costly replacements.
Another common battery chemistry type is lead acid batteries. This battery type was invented in France during the 19th century, making it the oldest and most mature rechargeable battery technology. Lead acid batteries are well-known for being the chemistry type used in car batteries.
Lead acid batteries are inexpensive, durable, and reliable, but their chemical composition makes them environmentally unfriendly. They are also slow to recharge and cannot be stored in a depleted state.
A more recent development in medical cart battery technology is the Lithium-Iron-Phosphate battery (LiFePO4). LiFePO4 batteries are safer to use, do not produce as much excess heat, and provide the longest cycle life possible.
The only downside to LiFePO4 batteries is their relatively high weight; a single battery is approximately 8 lbs. However, this relative disadvantage is far outweighed in the long run by its many advantages for medical carts.
Battery capacity and charge rate
Measured in watt hours (Wh), this number measures the quantity of energy stored in the battery. The higher the number, the longer the battery life.
Typical lead acid batteries for mobile computer carts possess a capacity of 300 to 500 Wh and a runtime of approximately 8 hours but require up to 12 hours to recharge.
Lithium-ion batteries are much lighter and can be recharged in less than 3 hours but possess a low capacity (200 to 250 Wh), resulting in a total runtime of 6-8 hours.
When under load (while powering or recharging), lithium-ion batteries tend to run hot. The older a Li-ion battery becomes, the hotter it gets to compensate for the loss of capacity. If not replaced quickly enough, the excess heat can cause it to bulge or burst.
LiFePO4 batteries developed by Scott-Clark Medical produce minimal heat, possess an excellent capacity of 330 Wh, and a runtime of up to 7 to 9 hours.
Combined with FMCPT technology and a dual-battery system, these batteries can keep a mobile computer cart powered for a complete shift with energy to spare for the next day.
With a charge rate of 2 to 3 hours, LiFePO4 brings together the durability and long runtime of lead acid with the fast-charging capabilities of a Li-ion battery.
In battery terminology, a rechargeable battery completes a cycle when it goes from fully-charged to depleted or near-depleted.
When a battery goes beyond a certain number of cycles completed, its battery life starts dipping; this is the point where the battery needs replacement. A long cycle life delays the need for battery pack servicing for longer.
Lead acid batteries have a relatively low cycle life, ranging between 300 and 600 full cycles, depending on temperature and care. This number translates into 3 to 5 years of continuous daily use.
Lithium-ion batteries vary greatly depending on the manufacturer and size, ranging between 400 and 1,200 cycles. However, because Li-ion batteries age even when not in use, they have an estimated life of approximately 3 years of daily usage.
Even when used daily, with proper care, a LiFePO4 battery can last up to 11 years before capacity falls under 80%.
LiFePO4 batteries are also at least 99% charge-efficient, meaning that at least 99% of the energy spent charging is transferred into the battery cells.
In contrast, Lead-Acid batteries possess a charging efficiency of 85 to 90%; the remaining 10-15% is lost in the form of heat.
Choosing the right battery type and technology helps your personnel become more efficient, spend less time on battery charging and management, reduce errors, and focus on their tasks and duties.
Investing in more efficient batteries results in a lower cost per Wh, driving the cost of ownership down and saving you money in the long run.
Scott-Clark Medical understands the need for high-capacity, long-lasting, high-efficiency mobile cart batteries. That’s why we partnered with UltraLife Corporation and jointly developed our own LiFePO4 mobile cart batteries, one of the world’s most efficient power solutions for mobile computer carts.
If you’re looking for a custom mobile cart design using our power system for your applications, don’t hesitate to contact us.