Charge batteries regularly to increase battery life and reduce operating costs
Your team should be checking and recharging batteries at least every 3-weeks. More when opportunities like overnight stops, weekend breaks, or vehicle inspections/repairs present themselves. Instituting a practice of top charging batteries - whenever possible - at least once every three weeks using an external charger will not only reduce costs associated with premature battery failure but can also lead to reduced fuel consumption of 1.5% to 3%.
Always use an external charger with charging output in amps =/>10% of the combined total high reserve capacity or amp hour capacity rating of the batteries in the bank. A 12V battery bank of 4 x 100AH (total 400Ah) or 4 x 180RC (total 720RC) should use an intelligent temperature-compensated 12V charger with a minimum 40-80 Amp output at 12V. If you have inverters in your vehicles to support additional loads, consider installing inverters with internal chargers built-in.
If possible, your staging/parking areas should install AC outlets where vehicles can access power to operate these external chargers. Your operators should be trained on how and why this is important. A good quality 12V-80A (960-watt) charger can easily be operated using a standard 110V AC wall outlet. Typical 110V outlets are capable of supporting a 1200-watt continuous draw.