Battery operated tools save time and in the windshield repair industry time is money but few things are more frustrating than grabbing a cordless tool only to find the batteries are not sufficiently charged.
While it may be impossible to determine when and where a battery will fail, proper maintenance and storage maximizes battery life and performance. How a battery is maintained depends on the type of battery. For the purposes of this tech tip we are going to focus on re-chargeable batteries and chargers sold by Delta Kits.
Sealed Lead Acid (SLA) Batteries
The largest battery that Delta Kits sells is the 12V SLA battery that fits in your tool box and is used to power 12V UV lights, drills, and moisture evaporators. The charge retention for SLA batteries is best among rechargeable batteries and they are not subject to memory. Leaving a SLA battery on float charge for a prolonged time does not cause damage. For maximum battery life and performance SLA batteries should never be allowed to drop below a 20% charge and should be left on a Delta Kits smart charger whenever not in use. Note: Optimal operating temperature for SLA batteries is 25°C (77°F). Performance suffers at lower temperatures and battery life is drastically reduced at higher temperatures.
Lithium Ion Batteries
The Delta Kits Ignite UV light is powered by a single 3.7V Li-ion 2400mAh battery (technically a cell). There is no memory and therefore no scheduled cycling required to prolong the life of a Li-ion battery. Leaving a Li-ion battery on float charge for a prolonged time does not cause damage. For maximum battery life and performance Li-ion batteries should be left on a smart charger whenever not in use. Delta Kits smart chargers hold two batteries and Li-ion batteries are relatively inexpensive so it is recommended that you keep a fully charged spare on the charger at all times.
Nickel Cadmium (NiCd) Batteries
The NiCd battery pack for the 4.8V Dremel is actually (4) 1.2V 700mAh batteries linked together in a series. Unlike the SLA and Li-ion batteries mentioned above, NiCd batteries prefer a fast charge and should be discharged from time to time to keep crystals from forming on the cell plates (referred to as memory) that will gradually cause a loss of performance. Dremel does not recommend leaving the battery pack in the charger longer than necessary and recommends should be fully discharged for long term storage. Battery packs should be removed from chargers once full charge is achieved (typically about 3 hours from full discharge to full charge). Since NiCd batteries are meant to be fully discharged from time to time it is a good idea to have a spare available.
With average use and properly maintained all three of the batteries above should last a minimum of 12 months. With light use usable life may be extended and with heavy use or improper maintenance, usable life may be less than 12 months. You can detailed information from Battery Univeristy here: What’s the Best Battery?.