Battery Electrolyte

In a lead-acid motorcycle battery, the electrolyte is a mixture of sulphuric acid and water. Chemical reactions between the electrolyte and the lead plates store and release electrical energy. In AGM batteries the electrolyte is absorbed in glass mats, in gel batteries it is thickened; lithium batteries use a completely different chemistry.

Older conventional batteries have filler caps: check that the level is between the marks and top up only with distilled water, never acid or tap water. Sealed AGM and gel batteries must never be opened.

Electrolyte is corrosive. Wear gloves and eye protection, keep it away from paint and wash any spills off with plenty of water. A battery that is left discharged sulphates and loses capacity, so use a maintenance charger over winter.