Site Master™ MS2085A/MS2089A User Guide : Instrument Overview : Battery Information
 
Battery Information
The batteries that are supplied with the Site Master may need charging before use. They can be charged using either the provided AC-DC adapter or the automotive DC adapter. The batteries can be charged in the instrument or removed for charging using an optional battery charger (refer to the product technical data sheet for ordering information). The batteries are installed at the factory and can be replaced by the user. Refer to the next section for information on removing the batteries. Battery information and status is shown in Battery Information.
Caution 
Use only Anritsu-approved batteries, adapters, and chargers with this instrument.
When using the automotive cigarette lighter adapter, always verify that the supply is rated for a minimum of 75 watts @ 15 VDC, and that the socket is clear of any dirt or debris.
If the adapter plug becomes hot to the touch during operation, discontinue use immediately.
Anritsu Company recommends removing the battery for long-term storage of the instrument.
Note 
The batteries will charge at a faster rate when the instrument is turned off.
To prolong the useful battery life, the internal charging circuit monitors the battery temperature. Normal charging occurs when the battery temperature is between 0 °C and 45 °C. Charging is paused if the internal battery temperature is outside this range.
In order to maintain the battery capacity and to keep the remaining capacity indicator (found in the Battery Information dialog) as accurate as possible, it’s recommended to run the through a recalibration cycle on the external battery charger every three months. Refer to the product technical data sheet for ordering information.
Replacing the Battery
The battery can be replaced without the use of tools. The battery compartment door is located on the lower left side of the instrument (when you are facing the measurement display). To remove the battery:
1. Push in and slide the battery door tab to the left to remove the battery access door.
2. Pull straight out on the lanyard to remove the battery pack from the instrument.
3. After inserting the new battery pack, press the battery door to secure it.
Note 
When inserting the battery, the battery contacts should face up and slide in first. If the battery door does not close tightly, the battery may be inserted incorrectly.
Battery Removal