BL1820 18V LXT 2.0Ah battery
It is replaced by the BL1820B 18V LXT 2.0Ah battery.
The BL1830 is 18 volt battery pack with a capacity of 2.0 Ampere hour for the Makita 18V LXT battery system.
The battery pack has a black plastic rounded rectangular housing. On the front is a single gray plastic latch which has to be pushed while the battery is pulled forward to release it from the machine.
The electrical contacts are in the the yellow plastic piece on top.
Inside this battery pack are ten 18650 Lithium Ion cells and battery management electronics to prevent damage to the cells by overheating.