Battery State of the Union
As we have stated before, the changes being implemented by OE car and truck manufacturers related to vehicle batteries and starting/charging systems are significant and seem to be accelerating each year, so much so that it can be difficult for shops and technicians to keep up. That’s why we are starting out with this quick primer, by Brendan Baker on UnderhoodService.com, on the “State of the Union” as it relates to battery utilization in today’s vehicles and how this area is evolving.
In it, he addresses many different topics related to battery service, including the shift to AGM batteries, the use of STOP/START systems, parasitic drains, module activity as a source of drains and more. Although it is not very long, he packs in a ton of information, each nugget of which could provide a jumping off point for further research.
We’d like to point out two specific items from his piece. First, he provides a photo of a Ford battery (BAGM-94RH7-800). We are often asked how to tell what type the battery is when charging. While things still aren’t perfect out there, in recent years, the battery manufacturers have done a much better job of labeling AGM batteries as such. This photo is a great example, where it shows how Ford has clearly marked this battery as an AGM battery. So, when charging this battery with a PRO-LOGIX charger, the operator would always want to set the charger’s battery type to AGM. Second, Baker cautions against the use of booster cables when jump starting electronics-heavy late model vehicles:
“Jump starting a vehicle with jumper cables from another car, for example, can cause voltage spikes that may weaken or destroy the battery cells in both vehicles. If you must jump start a customer’s vehicle, use an auxiliary starter battery, or a battery pack that won’t spike the voltage.”
While we manufacture and sell booster cables, whenever possible, it is best to use a jump starter for this purpose. It is far more straightforward (less likely to result in an improper connection) and a jump starter cannot cause voltage spikes when used correctly.
Is it the Transmission or the Battery Connection?
We have highlighted in the past the importance of good connections, whether it is the battery connections or ground connections throughout the vehicle, and how a poor or compromised connection or cable could have a wide range of negative consequences for vehicle operation. This article, by Mike Greer on TransmissionDigest.com, dives into the consequences of bad connections in detail, using case studies to illustrate the issue. As he notes,
“In this article we will discuss bad connections, starting with the battery and ending with, well, the battery. Seemingly every week, we… get a vehicle in that has an issue at the battery terminals; and if it isn’t causing an issue right now, it will sooner or later.”
He then jumps into his case studies, involving a 2009 Honda Civic, a 2014 Honda Pilot, a 1999 Toyota 4Runner and a late model Hyundai. In each case, the problem was identified by another shop as a serious and/or involved repair related to the vehicle’s transmission. Yet, in every case, the actual fix turned out to be related to damaged/compromised battery cable connections. One customer even brought in a used TCM that they purchased and were asking to have installed, yet the issue was a horrible battery connection. As we noted in last’s month’s feature article, sometimes vehicle problems have very complicated and difficult root causes but sometimes it comes down to addressing the basics. This article does a great job of showing the importance of getting the basics right.
Corvette Cable Issues
The cable integrity issue is a big one. We see it show up in so many unlikely places, resulting in everything from No Start complaints to driveability issues. It really knows no bounds. To emphasize its importance, we are highlighting this TSB from GM published earlier this year and covered on AutoServiceProfessional.com. It warns that code B1517 could be set in one or several modules on 2014-2019 Corvette models and provides a procedure to resolve the code. Essentially, the technician is to check for and resolve a loose wire connection on the negative battery post harness. Correct the poor connection and you resolve the problem – it’s that simple. Yet, something so simple could be the source of much anguish, with a technician chasing down blind alleys trying to resolve the customer complaint.
Quick Diagnostic Checklist
When it comes to diagnosing battery health and charging system performance, the days of simple assessments are long over. On today’s vehicles, the battery’s health/charge routine are managed by control modules that are commanding the charging system to perform based on specific parameters, such as temperature, battery state of charge (SoC), electrical system demand and more. This quick article, by Andrew Markel on Import-Car.com, provides a quick yet thorough review of the challenges of modern system analysis. Similar to the first resource above, it could serve to provide a great jumping off point into topics where you would like to dive deeper to expand your knowledge and improve your diagnostic game. We think a few of his points are well worth highlighting.
First, as he commands, “look it up.” At first glance, you might see charging output in a range you perceive as too high or too low or no output at all and quickly condemn the alternator. Yet, the best practice is to reference the service information to determine how the alternator’s output is controlled and then, if warranted, use a scan tool to verify that the “too high” output is exactly what the system is commanding. Secondly, beware of add-ons to the electrical system. These can often be the source of trouble, especially when they are connected at the battery. As he states,
“It is a bad practice to use the positive and negative battery terminals to power aftermarket accessories on some vehicles. These can change the internal resistance of the battery. Extra connections can cause the battery to incorrectly report the state of discharge, despite a normal battery condition.” Great advice.
Keyless Entry Conumdrum
We’ll leave you with a weird one related to the vehicle’s power system. This quick GM TSB, highlighted on AutoServiceProfessional.com, notes the potential unintended impact that can result from leaving an accessory connected to a vehicle after it has been turned off. In this case, GM warns that vehicles from 2014 and older can have their remote keyless entry and remote start functions impaired by aftermarket devices left stored in the vehicle, such as a USB charger plugged into an accessory port. Go figure. At the end of the day, this TSB reminds us of how interconnected all of a vehicle’s electrical/electronic systems are and how, if one aspect of a system is slightly off kilter, it can have negative knock-on consequences throughout the entire vehicle.
OK, so, there you go. We hope that these resources prove useful as you march forward into Battery Season. Have you ever had a difficult repair that caused you to chase down several different possibilities only to find that the root cause was a battery or battery connection issue? We’d love to hear about it in the comments below.