Yuasa 51814, 12v 19Ah BMW Motorcycle Batteries. L(mm) W(mm) H(mm) 186 82 171. Note: Before use this battery requires filling with sulphuric acid. The acid is not supplied with it because it is classed as hazardous material and it will not be accepted for carriage by our delivery agents. You should however be able to obtain suitable acid at any good local motor spares distributor.