Common Roadside Service Calls Part 3: The Jump Start | Semi Truck Repair
The final installment of our common roadside service post highlights the jump start. A semi truck battery at spring and summer temperatures has all of it’s power to utilize. The problem comes in when the temperatures drop below 40 degrees. The colder the temps get, the less charge a battery will retain as the chemicals inside the battery thicken and slow down the charging and powering process. A study from the Agricultural Extension Service at the University of Tennessee found that:
“A battery that has all of its power available at 80º F will have only about 46% of available power at 0º F. Plus, the engine will be 2.5 times harder to start at 0º due to thicker oil and resistance to movement of internal moving parts. In effect, an engine is about five times harder to start at 0º F than at 80ºF.”
As is our commonly repeated motto – preventative maintenance here is key. We penned a post last year mentioning how we routinely schedule (novel idea, right?) our own trucks out of service at various times throughout the year to run them through a PM process specific to the season that is approaching. One of those such processes is that of a regular battery and systems check we do right as the kiddos head back to school. (You know, before the temps drop?)
One at a time we bring our trucks into the shop and run a load test to see how much “juice” the battery has remaining. The newer a battery is, the less likely you are to need to worry about it. BUT, even with that being said, Murphy’s law dictates that you should check it anyway. If you are getting close to the end of your 4 – 6 year life cycle on a battery though, you could save yourself some downtime and expense by pulling it and installing a new one. Additionally, while you’ve got your truck in the shop, it’s a good idea to check your starter, alternator, and charging systems as well.
So that about covers preventative measures…. but what about the reactive measures? What do you need to pay attention to when you’re jump starting one of your trucks? Or what can you fully expect from us when we do the same?
To begin with, you’re going to want to make sure that you’ve taken care of your jump start unit. We at JAM use Goodall Products and have found them to be both powerful and quick. Last winter alone, we could expect to jump a good number of tractors before the charge would even start to flicker on the unit. These types of starters are must haves for large fleets with terminals in colder climates. And, as might seem obvious, if it is possible to store your starter in a warm environment, do so.
Before you attempt to jump start your battery you’ll want to make sure that all of the connections are tight and secure and that the battery posts themselves have not been corroded. On top of that, you’ll want to ensure you’ve got a good ground to connect to such as a heavy metal piece of the chassis itself or the engine.
When connecting your cables to the battery itself, be sure to use the battery that’s closest to the starter so that it gets the maximum amount of starting power and less is lost via transference through the battery bank. Also, once you jump start your engine, keep in mind that many heavy duty batteries will take a full day to completely recharge. (So if you’re running a P & D route, you’ll want to be sure you’re not shutting the vehicle off so it can remain continue to charge throughout the day.)