Following OEM specifications along with using OEM or compatible software and tools is important when handling low voltage systems and batteries, panelists at a Collision Industry Conference (CIC) meeting July 10.

Don Seyfer, National Automotive Service Task Force executive director, said battery designs and charging systems are changing, not only for electric vehicles (EVs) but also internal combustion vehicles engine (ICE) vehicles.

“We used to have a little set of relays that control the battery and kept it at a certain charge and now it’s much more sophisticated,” Seyfer said about ICE vehicles.

Other conditions such as where a vehicle is can also play a part, such as extreme cold or hot climates, he said. It is important to check vehicles for pre-existing conditions as they come in, he added.

If a problem is found, Seyfer said it’s important to have the right battery charger designed for the battery’s chemistry. It is also important to know what “fully charged” means.

“Most EVs and modern ICE vehicles have a very carefully managed level of charge,” Seyfer said. “They usually are looking for a 40% to 80% charge.”

A 100% charged 12-volt battery is charged at about 12.7-13.2 volts, not 12 volts, he said.

“In fact, if that battery is down to 12 volts, it is basically discharged,” Seyfer said.

He said overcharging or undercharging batteries can hurt them. This typically won’t happen unless a battery is being charged manually — this is where the correct equipment is critical, he said.

“I know you love hearing, we always love hearing, we have to buy more tools,” Seyfer said and expanded for the audience the necessity to prioritize working with updated charging systems and tools.

Inadequate charges can damage the generator or alternator and starters by overworking, he said. It can also cause diagnostic trouble codes that are hard to diagnose.

Sometimes scan tools and computer systems won’t properly inform you that a battery is low, he said. OEM-specific service information is needed to make proper determinations.

Many modern charging systems also draw currents while sitting, he said. He said an additional power supply might be needed if you are doing remote scanning or calibrations to maintain battery voltage.

The current, voltage, and temperature have to be regulated during charging, he said.

“It seems to be becoming a more and more common issue that vehicles that are pretty new have batteries that are not up to the task and can set diagnostic trouble codes and give you a major headache trying to diagnose them,” Seyfer said.

A fast MN/MX or Peak min/max Digital Volt-Ohm Meter tool can help with finding voltage changes, he said.

Scott Baumfalk, shop foreman at Automotive Imports and instructor at Automotive Certified Training Academy in Colorado, said the industry is starting to see more 48-volt mild hybrid systems.

He said the battery first started emerging decades ago but they’ve started to be introduced again with better technology. Repair facilities will encounter all lithium-ion batteries, he said.

The 12-volt system is critical to a 48-volt system, he said. This includes a set of contactors that the 12-volt battery needs to close for the 48-volt system to function.

For example, Mercedes has a 48-volt hybrid system that houses a 12-volt battery, a 48-volt battery, and a DC/DC converter. It also has coolant that runs through the enclosure to thermal regulate the internal components, similar to a high voltage UV battery.

“It’s trying to keep this battery cool in the summertime and warm in the wintertime,” Baumfalk said. “That means that even when the car is off if this battery gets cool enough, it’s going to turn on an electric heater, warm up some coolant, and run some coolant through this battery.”

The more voltage a vehicle can store, the more accessories vehicle owners can use without a failure, he said.

Smaller cables can also be used with a larger voltage lowering production costs, he said. The 48-volt systems also work with start/stop systems that lower emissions.

“The simple start/stop system that we’ve become acclimated to lowers emissions somewhere between 5% and 12% depending on whose study you’re reading,” Baumfalk said.

Mercedes has eliminated the mechanical 12-volt start in their system, he said.

“They have no belt, they have no accessories on the front and they start and stop this engine and regulate and generate electricity all through an integrated starter generator between the motor and transmission,” Baumfalk said. “If this battery fails or if the 12-volt battery gets too low, this car will not start. It will not move and you’ll be likely calling a tow truck or someone that has a lot of experience with these in order to get this car up and running.”

The changes allow for an increase in performance, he said. ICE vehicles didn’t have a lot of horsepower performance from zero.

“With some of the technologies, you’re going see an increase in performance from somewhere around 5 to 9 horsepower right off of a stop,” Baumfalk said. “And the Mercedes system in particular is actually greater than that, somewhere around 20 horsepower from a stop.”

The batteries have some similar hazards to 12-volt batteries, such as possible toxic gasses emitted as they heat, cool, and charge.

“They’re also highly flammable,” Baumfalk said. “Because there will be gasses internally in these enclosures, they’re vented to the outside atmosphere, and in the repair industry — collision industry in particular — where you have a lot of sparks potentially and a lot of heat, you’re going to see more gasses and you’re going to have more potential for fires or flashes or somebody getting ill from the fumes of these batteries.”

If a cell voltage cannot be balanced and a lithium-ion cell falls below 2 volts or near 2 volts, it can switch polarity and cause a runaway or thermal event, he said.

“These batteries are located all over the place in these automobiles and the Mercedes enclosure, in particular, are often mounted under the hood where they have coolant running to them and if they get damaged and they get coolant on those cells or a liquid, they will have a very serious thermal event in short order,” Baumfalk said.

The severing of a cable running to a battery receiving power could also end in a larger thermal event, he said.

He said the Mercedes system is unique in that it keeps all the components compact in a smaller, centralized area.

Baumfalk also used an example of an Audi 48-volt system using a starter motor or integrated starter generator. He said on some Audi models, the battery system sits in the lower right-hand corner and a frontal impact would likely cause damage.

“You’re going to lose coolant,” he said. “You’re going to have to replace these alternators or starter generators. These will also have to be programmed.”

In Baumfalk’s example, the Audi system had the 12-volt battery, 48-volt battery, and DC/DC converter in separate areas on the vehicle, in contrast to the Mercedes example. With a separated model, cables that are either purple or light blue will be found in different locations on a mild hybrid, he said.

The voltage won’t be present in any function where the car wouldn’t be driven such as the keys out of the vehicle or a door or hood open, he said.

The separated system is more common for OEMs he said.

“I think the reason they have gone to this particular system is it was easier to integrate a mild hybrid system on an existing platform rather than redevelop an entire platform like Mercedes did with their integrated starter motor between the engine and transmission,” Baumfalk said.

OEM-specific software and a suitable charger to close the contactors is the only way to allow the 48-bolt battery to take a charge, he said.

Baumfalk shared a story about how he was working on a BMW 12-volt lithium-ion composition battery and it kept giving a warning of battery failure but the car would continue to start.

“Well, bad on me. I didn’t hook it up to manufacturer software to say, ‘Hey, was this a problem?”

The vehicle was sent to the dealer, he said.

“And they said, ‘Hey, there’s a date and time stamp here that says this car was left in reverse with the key on at such and such a time at such and such a date and the battery has failed,’” Baumfalk said.

He added that it was a $3,000 battery.

“The 48-volt battery is going to be much more expensive,” Baumfalk said. “You guys in the collision industry are working on cars that are still in warranty much more than I am.”

Hybrids can draw up to 500 milliamps throughout the day, he said. He suggested isolating the 12-volt battery before starting work if the battery is in a good state of charge. If removed from the system, it won’t be able to talk to the 48-volt system, he said.

It also will keep an over-the-air software update happening that could take energy, he said.

“If it happens to fire that update up in your garage or your repair facility, it’ll just keep draining the battery, or you may have modules that are compromised or wiring compromised that would prohibit this update from occurring and corrupt the data that it’s sending through to update these modules,” Baumfalk said.

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Chuck Olsen, Donny Seyfer and Scott Baumfalk during a panel at Collision Industry Conference (CIC) meeting July 10/Teresa Moss.