Lead acid battery maintenance

Keeping A Healthy 12v Battery Pack!

by Ken Harbour on May 27, 2009

In our experience, one of the quickest ways to destroy a lead acid battery set is to regularly discharge it to a low voltage. We would not advise running a battery below around 75% capacity or below around 12.3v as it’s life will be dramatically shortened.
Battery condition / state of charge chart

Battery condition / state of charge chart

Another area which must be regularly checked is the external condition of the battery top(s) including vent plugs, caps, terminals and connecting cables.  After several months in service, a Lead Acid battery can produce a fine ‘mist like’ corrosive film on itself including it’s terminals and cable connectors. left unchecked this will result in problems including a higher rate of self discharge and eventually corrosion. Just one year of poor maintenance can put a battery into an early decline and see your project failing prematurely.
A battery can be cleaned quite easily using a prepared mix of water soapy water to wash away the layer of acid encrusted dust (the layer of mist). Acid spillages or more prominent areas of ‘sweating’ or damp should be removed using a strong solution of baking soda in water, finally rinsing with clean water. Care must be taken to avoid any cleaning substance entering the battery, vent plug or any automatic battery top up devices. After cleaning, a nice smear of petroleum jelly can be liberally applied to any metal parts and contact areas. Ensure that all connections are tight, corrosion and rust free. Cables with any visible damage, burns or missing insulation should be repaired or replaced to prevent future problems.