Operation; Batteries - Trace Engineering LEGEND II Manual

This section of the manual is included to help you better understand the factors involved with battery
charging, care, and maintenance, by discussing the physical make-up and characteristics of
chemical storage batteries. This is not intended to be an exhaustive discussion of battery types, but
simply a guideline. The manufacturer of each specific battery is the best authority as to its use and
care.
Batteries come in different sizes, types, amp-hours, voltages and chemistries. It is not possible here
to discuss all aspects in detail. However, there are basic guidelines you can follow that will help in
battery selection and ensure that your batteries are better maintained than the majority.
A description of battery charger operation requires the use of terms with which you may not be
familiar. The following terms appear in the description of batteries and battery charger operation.
ä Electrolyte: Typically a mixture of water and sulfuric acid, it is commonly referred to as
battery acid.
ä Plates: Originally made of lead, now fabricated from lead oxide. Plates connect to the
battery terminals and provide a structure for the chemicals that create current. There are
several plates in each cell, each insulated from the other by separators.
ä Sulfating: As a battery discharges, its plates become covered with lead sulfate. During
recharging, the lead sulfate leaves the plates and recombines with the electrolyte. If the lead
sulfate remains on the plates for an extended period of time (over two months), it hardens,
and recharging will not remove it. This reduces the effective plate area and the battery's
capacity.
ä Stratification: Over time, a battery's electrolyte (liquid) tends to separate. The electrolyte at
the top of the battery becomes watery while at the bottom it becomes more acidic. This
effect is corrosive to the plates.
ä Deep Cycle: A deep cycle occurs when a battery is discharged to less than 20% of its
capacity (80% depth-of-discharge).
ä Temperature Compensation: Peak available battery voltage is temperature dependent.
As ambient temperatures fall, the proper voltage for each charge stage needs to be
increased. An optional temperature-probe (BTS) automatically re-scales charge-voltage
settings to compensate for ambient temperatures. The compensation slope based on cell
voltage is -2.17mv per degree Fahrenheit per cell (30mv per degree Celsius) for lead-acid

batteries.

WK