其中一個可能出問題的是手控掣內的電池, 這是一塊3V鈕型電池, 位於手控掣內。新版的使用手冊指出:
即這枚電池與手控的時鐘有關, 如電池沒有電, 關機再開時, 時間會不正確。(ZEq25和CEM30 等要GPS再由人造衛星取得時間後才會時間正確)2.5. Check the Battery
The hand controller has a real time clock (RTC) which should display the correct time every time the mount is turned on. If the time is incorrect, please check the battery inside the hand controller and replace it if needed. The battery is a 3V, CR1220 button battery.
但在做Alignment時, 是需要關機再開機以確定「零位」(zero position)的。手冊:
這是指望遠鏡指向北極(或在南半球指向南極)的位置。而確保手控確認零位, 方法是關上赤道儀電源再重開, 如手冊18頁所述:5.4. Align
... The mount has to be at Zero Position before performing any star alignment.
但如果內置電池沒有電, 但關上電源後再開機, 就會時間錯誤, 那當然沒法做alignment和GOTO。STEP 10. Return Mount to Zero Position
After polar alignment ... after each adjustment. Remember, the hand controller needs to be at the Zero Position as well! The simplest way is turn the mount power OFF and ON again to reset the hand controller.
我的ZEq25手控掣, 電池失效了, 也是做成一派混亂的成因之一。建議用家每兩年換一次電池(CR1220, 十多元一塊), 確保不會電池失效做成問題。