In this edition of our battery tips, we speak with Rotronics Managing Director Ken Clark to discuss how different battery types should be tested.

Here is what he had to say.

Types of 12v vehicle batteries.

Hi Ken, thanks for joining us. To get us started, what are the main types of vehicle batteries you would see in a workshop?  

The most common types of 12v batteries are Lead Acid, which include Flooded, EFB, and AGM batteries. These can be doubled up in 24v battery sets.

We are seeing an increased use of 12v Lithium-ion batteries present in prestige cars from vehicle manufacturers, due to the growing power requirements in vehicles, and the rise of EV/PHEV vehicles.

Thanks for this Ken. So when should these 12v battery types be tested?  

An EFB, AGM, or Flooded battery should be tested at every opportunity in a workshop to identify battery defects before they become costly non-starts or future breakdowns.

For 12v Lithium-ion batteries, there is currently no means of testing the battery as these are supported by their own battery management system (BMS), however they should be charged with a compatible charger. 

What are the different technologies and applications of 12v battery types?

Lead acid batteries have always been used for their cranking capacity in vehicles. However, over the years, the introduction or stop/start, PHEV, or BEV vehicles require different technologies to support vehicle loads and capabilities.   

Flooded Lead Acid batteries are typically found under the bonnet, including EFB batteries, which are commonly used for start/stop applications.

Within passenger environments, typically AGM batteries are used. As a rule of thumb, vehicles which have stop/start or PHEV technology, will typically have an EFB or AGM battery in use.

The maintenance requirements of 12v vehicle batteries.

If we look closer at the maintenance requirements of each battery type we have discussed, what battery diagnostic equipment do you recommend?

12v Lead Acid batteries such as Flooded, EFB, and AGM batteries can be tested using most conductance-based battery testers present in the marketplace.

If you’re looking for additional features such as printable test reports, wirelessly updatable software, or a 24v battery balancing feature, this is where it becomes important to weigh up your battery tester options, as not all conductance-based battery testers are created equal.

We recommend the MDX655P S/S battery tester as a great all-rounder, suitable for most battery types. However, if you’re looking to specifically test fleet vehicles, the EXP1000FHD is useful, due to its VIN and fleet number recording capability, meaning workshops know exactly which vehicle in a fleet has been tested.

If you’re looking for the most advanced testing capability for any Lead Acid battery application, the CPX900 wins our vote. The conductance profiling technology supports modern vehicles with reserve capacity problems, an essential component for stop/start applications, where battery capacity is more important than starting capacity alone.

If your workshop requires an all-in-one diagnostic solution, the DCA8000 should be considered as this gives one of two results, good and fully charged, or replace decision. This minimises the downtime in workshop diagnosis and ensures batteries which require charging are fully charged, prolonging battery lifecycle performance.

What about Lithium-ion batteries, as you mentioned there is no way to currently test them?

Lithium-ion 12v batteries are slightly different, as there are currently no means of testing a 12v Lithium-ion battery. They have their own internal battery management system (BMS), and they are designed to stop users discharging the battery to a critical level, by opening and closing the relays. 

Essentially, when 12v Lithium-ion batteries suffer excessive discharging, the relays in the battery open to prevent further damage by breaking the circuit. When this happens, the battery no longer provides power.

The only way to close the relays and return the battery to normal use is by using a Lithium compatible charger, such as the Midtronics MCC-070, or the CTEK PRO series (PRO25S, PRO25SE, PRO60, and PRO120). 

Speaking of Lithium-ion, the newest type of 12v vehicle battery; do you see any new 12v automotive battery technologies arriving in the next ten years?

There was talk about Cobalt and 48v batteries, but 12v Lead Acid batteries have been around for over 100 years in automotive applications.

I don’t see the technology changing drastically any time soon, and even in most modern electric vehicles (EV), you will still find a 12V AGM Lead Acid battery.

Instead, vehicle technology is continually changing with an increase of EV vehicles. 12v batteries will eventually change applications, providing power to systems and no longer providing cranking capability to batteries.

Each automotive battery type comes with a range of maintenance requirements, alongside positives and negatives. Flooded batteries are cost-effective, but outdated for modern start/stop and EV vehicles, whereas EFBs are suitable for start/stop applications, but are still prone to leaking and gassing.

AGM batteries are spill proof and don’t release gas, but they are more expensive than other Lead Acid batteries. Lithium-ion 12v batteries are even more expensive than AGM batteries, but they last longer and have safety procedures in place to prevent critical discharging.

If you have any questions about maintaining battery types, or you would like to speak to a member of our team, contact 0121 514 0605.