The Complete Guide to Floor Equipment Batteries
- What Are Floor Equipment Batteries?
- Floor Equipment Battery Safety Guidelines
- Working with Floor Equipment Batteries
- Advanced Battery Tips From Floor Equipment Experts
What Are Floor Equipment Batteries?
3 Main Battery Application Types
Starting or SLI (Starting, Lighting, and Ignition) Batteries
These batteries are most commonly used to start and run engines since engine starters require a large starting current for a short amount of time. The plates of these batteries are very thin in order to cover a large surface area. The plates are composed of a lead "sponge," which is similar in appearance to a very fine foam sponge. Not appropriate for use with battery-powered floor equipment. Use for starting propane and gas engine equipment.
Deep Cycle Batteries or Traction Batteries
These batteries are composed of thick, solid lead plates which allows them to be discharged down as much as 80% of battery capacity. The thick plates decrease the surface area giving the batteries less “instant” power that starting batteries need. These batteries are ideal for battery-powered floor equipment.
Marine and Pseudo Cycle Batteries
Marine batteries are usually a “hybrid” and fall between the starting and deep-cycle batteries. The plates are composed of lead sponge but are heavier and coarser than starting batteries.
These batteries are composed of thick solid lead plates which allows them to be discharged down as much as 80% of battery capacity. The thick plates decrease the surface area giving the batteries less “instant” power that starting batteries need. These batteries are ideal for battery-powered floor equipment.
3 Main Battery Construction Types
Flooded or Wet Cell
These are the most commonly used batteries as they provide the lowest cost per amp-hour. The plates are submerged in an acid “bath” and require adequate water levels at all times.
Absorbed Glass Mat (AGM)
These are a class of valve-regulated lead acid batteries (VRLA) in which the electrolyte is held in glass mats as opposed to freely flooding the plates. The acid is contained within sponges in between the plates. Because of their sandwich construction and low internal resistance, they can charge and discharge at a much faster rate than the other types. AGM and gel batteries are the only “sealed” options.
Gel
A silica gelling agent is added to the battery’s acid solution, which creates a semi-stiff paste in between the plates. This greatly reduces gas and volatility of the cells.
Batteries are composed of multiple 2V cells. The number of cells in a battery determines the total voltage of a battery.
Example: Three 2V cells = One 6V battery
(Note: Actual voltage is 2.12V x 3 = 6.36V)
AGM and Wet Batteries
AGM
- Advantages
- Maintenance free
- Air transportable (non HAZMAT)
- Spill proof/Leak proof
- Minimal corrosion
- Installs upright or on side
- Low to no gases released
- Disadvantages
- More expensive
- Sensitive to overcharging
- Voltage regulated chargers must be used
Wet
- Advantages
- Longer deep cycle life
- Maintained by adding distilled water
- High discharge rate capability
- Better availability worldwide
- Long, proven history of use
- Disadvantages
- Periodic maintenance is required
- Only can be used in upright position
- Produces gas while charging
- Can be spilled
- May emit acid spray if overcharged
- Requires ventilation
- Cannot be shipped by air (HAZMAT shipping)
What are Amp-Hours?
All deep cycle batteries are rated in amp-hours (AH). An amp-hour is one amp for one hour (amps x hours), or 10 amps for 1/10 of an hour.
- For instance, if you have something that pulls 20 amps and you use it for 20 minutes (or 1/3 of an hour), then the total amp-hours used would be 6.67 AH (20 amps x 1/3 hours)
The generally accepted AH rate for nearly all deep cycle batteries is a 20 hour rate. This means that the 12V batteries are discharged down to 10.5 volts over a 20 hour period while the total actual amp-hours they supply are measured. Sometimes ratings at a 6- and 100-hour rate are given for comparison and different applications.
- The 6-hour rate is often used for industrial batteries, as that is a typical daily duty cycle
- Sometimes the 100-hour rate is given simply to make the battery look better than it actually is. It is also useful for figuring battery capacity for long-term backup amp-hour requirements
Battery Chemistry
Lead-Acid Batteries
- 155 year old technology
- Utilizes an Oxidation/Reduction Reaction (Redux) between sulfuric acid solution and lead/lead oxide plates.
Sulfuric acid is converted into water during discharge.
- Specific gravity can be used to determine acid concentration, and therefore the state of charge.
- Discharged batteries can freeze at a higher temperature than a fully charged battery.
- Overcharging will cause electrolysis of the water, releasing free Hydrogen and Oxygen, which is an explosion hazard.
- This water will need to be replaced over the life of the battery.
Battery Configurations
Before deciding how to connect your batteries, you first must determine:
- which batteries will be used (based on your system voltage)
- and how many batteries will be used (space is usually the primary limiting factor).
Series Connect (Most Common in Floor Care)
To increase voltage, connect batteries in a series. This will not increase the system capacity.
Example Two 6V batteries at 225Ah connected in a series
System Voltage 6V + 6V = 12V system capacity = 225Ah
Parallel Connect
To increase capacity, connect batteries in parallel. This will not increase the system voltage.
Example Two 6V batteries at 225Ah connected in parallel
System Voltage 6V system capacity = 225Ah + 225Ah = 450Ah
Series/Parallel Connect
To increase both voltage and capacity, connect additional batteries in a series and parallel.
Example Four 6V batteries at 225Ah connected in series/parallel
System Voltage 6V + 6V = 12V system capacity = 225Ah + 225Ah = 450Ah
You may connect a series of six 6V batteries or three 12V batteries in order to meet the requirements for a 36V system. However, the size of your battery compartment, your performance requirements, and your price range may all limit your options.
Connecting batteries in series does not increase the capacity of the batteries. It simply increases the overall voltage to meet your system requirements. Once your voltage requirements are met, and if space allows, you can double the batteries in parallel connection, which doubles your battery capacity.