The Traxx Mobility Systems Titan 500 is a patient lift system for the home. The electric motor is rated to lift up to 500 pounds. Two rechargeable 12V sealed lead acid batteries are used to power the system.
Lead Acid batteries are a time-tested design and offer lower costs than newer battery technologies like Lithium Ion. However, their advantages in cost and storage can be offset by their size and weight. This post is designed to act as a guide to the differences between the two types of batteries and the reasons why we chose to used sealed lead acid batteries in our patient lift motor.
Lithium Ion batteries are a newer technology. They are a different type of electrochemical battery that requires separate safety considerations. There is a danger of explosion if moisture corrodes the cell. Volatility must be closely managed and addressed. Lead Acid batteries pose different risks, which have been addressed in the design of the sealed types. Charging limits or valves keep gasses from building up, which could become explosive. Acid is in a gel state which prevents it from leaking should it be damaged. It is very important to use the correct charger for the batteries as they provided safety features to protect you and the battery.
Li-Ion batteries are idea for digital devices as they are good at providing a constant feed of energy. However, the charge decays quickly when not in use. Once again, fine for your phone that is constantly working, but not so good for a patient lift if you have to continually charge it. Sealed Lead Acid batteries prefer a “shallow” or short discharge, once again, ideal for a patient lift that may run only a few times a day and be idle the rest.
Sealed Lead Acid batteries work better in a patient lift as they are much more powerful and they hold a charge much longer than a Li-Ion battery. They retain their charge four times the amount of a Ni-Cd battery.
Some of the downsides of Sealed Lead Acid (SLA) batteries is the longer charge times, the larger size and weight and the fact they must be stored in a charged state when not in use for longer periods of time. The latest lead acid batteries have addressed safety issues over the years through technology.
Unlike the flooded lead-acid battery, both SLA and VRLA (valve-regulated lead acid) are designed with a low over-voltage potential to prohibit the battery from reaching its gas-generating potential during charge because excess charging would cause gassing and water depletion. Consequently, these batteries can never be charged to their full potential. To reduce dry-out, sealed lead-acid batteries use lead-calcium instead of the lead-antimony. [Battery University]
To reiterate, Lithium Ion batteries are expensive, can be volatile, do not hold a charge over long periods of time and are ideal in situations where smaller size and weight are required. Sealed Lead Acid batteries are less expensive, are relatively safe, hold a charge for longer periods of time and are best for situations where more power is needed and size and weight are less of an issue.
We hope this has shed some light on the batteries we use in our patient lift system. We have weighed the issues of power and safety and chose the best battery for the application. Remember to charge your batteries weekly under normal operating conditions, only use the charger that ships with the unit and keep the motor unit clean and dry.