As temperatures change and customers are returning coaches into service,
MCI offers the following reminders for coach batteries:
Test voltage on each battery individually with multi-meter
- If voltage reading on each battery is 12.4 volts or higher, charge is enough to start engine
- If voltage reading is less than 12.4 volts, charge or replace batteries before starting engine
- Remember, this is only telling you part of the story.
Inspect physical appearance, terminal connections and securement
- Look for bulging sides, leaking, excessive contaminants on top – Replace or clean
- Battery Terminal Connections must be clean and secured properly
- Battery hold down secured properly
- Battery Cable connections – As a reference, there can only be a voltage drop at a single connection of 1/10th of a volt. And a voltage drop on a on an entire branch of .5 of a volt.
- Check the Electrolyte level and Specific Gravity of each Cell
- Perform a load test – Only if all the above checks are satisfactory
Take the time and deal with dead or discharged batteries properly!
- Jump or boost starting should be avoided whenever possible, especially when batteries are completely depleted, i.e. below ~10.5 volts
- Alternators are designed to maintain batteries & electrical system, not charge them! Discharged batteries never fully recover and alternator life is diminished.
- Onboard Inverter/ battery charger may not work with batteries below ~10.5 volts
- Reminder – Batteries are the heart of the electrical network, if not properly charged with solid connections, any additional electrical system test are likely going to be skewed