Battery Equivalents and Replacements

16 Volt Battery: Guide To 16V AGM and Lithium Batteries

16-volt batteries are typically used in drag racers, circle track racers, and other racing cars and vehicles, in general, to help lower the weight of the electrical systems and to improve reliability, fuel efficiency, to crank larger engines, etc.

To reduce the weight even further, many racing vehicles lack alternators and charge controllers, requiring their batteries to work harder than typical car batteries since they must crank large internal combustion engines and power all electronic and electrical systems during the race.

Published: January 16, 2023.

drag racer burning tire

Why 16V Instead Of 12V?

16V electric systems in vehicles offer many benefits over 12V electric systems, especially in terms of power and energy.

If check the following formulae:

P (W) = U * I = U2 / R

It means that the same electric system, when being powered by 16V instead of 12V, develops ~78% more power for a 33% increase in voltage.

So, why not just jump to 24V? That would be 300% (4x) more power for a 100% increase in voltage, right?

Well, an increase in voltage from 12V to 16V means that many components intended for 12V systems can be used in 16V electric systems, or they have to be modified slightly.

But, to jump from 12V to 24V requires plenty of modifications to various electric subsystems and components found in cars, boats, yachts, etc.

Direct Benefits of 16V Electric System

When compared with 12V, 16V electric system improves the following:

  • Ignition systems: higher voltage also means hotter sparks and larger spark plug gaps, increasing fuel efficiency. In race cars, fuel efficiency is not important for increasing the millage, however, more fuel burned in cylinders, means more power for racing.
  • Engine starters can crank larger engines more reliably.
  • Water and fuel pumps can pump more liquids at any given time, improving the cooling (the cooling system can be smaller and lighter) and potentially increasing the engine power.
  • Electric fans spin faster, increasing the air speed and air volume, improving their performances, etc.

Weight savings thanks to the increased power of the electric system and generally improved engine performance lead to better racing times.

And to increase weight savings even more, some racing cars are designed without alternators and charging systems and are based on 16V maintenance-free AGM and lithium batteries.

16V AGM Batteries

16V AGM (Absorbent Glass Mat) batteries feature 8 cells connected in series for a nominal voltage of 16V and an actual voltage of ~17V (battery fully charged, charger disconnected).

AGM batteries are very reliable batteries, resistant to vibrations and mechanical impacts, can be operated in almost any position (except upside down), they are spill-proof, maintenance-free batteries.

xs power d16 31

Thanks to the AGM technology, AGM lead-acid batteries tolerate deep-discharge operations much better than wet/flooded lead-acid batteries and are often used even in vehicles with no onboard alternators.

However, it is very important to recharge them after each race or track session to improve their operating life.

AGM 16V batteries range from smaller group 34 batteries (or even smaller) to larger group 31 batteries (or even larger).

Also, 16V AGM batteries can be connected in parallel to increase their cranking abilities even more - just be sure to use the very same batteries (not only the same brand but also the same model) to avoid any imbalances.

kinetik 3 pole 16v battery

A special type of 16V AGM batteries are three pole batteries having common ground, 12V battery terminal, and 16V battery terminals.

Such batteries allow the user to run certain systems at 12V and other systems at 16V, which is great. On the other hand, such batteries are prone to cell imbalances, and premature failure due to cell imbalances and must be recharged with battery chargers that automatically provide cell balancing.

Note: Personally, I like the KISS principle - "Keep Things Simple and Stupid," especially on heavily stressed systems like racing cars, so either run all your systems at 16V or at 12V. Just my 2c.

16V Lithium Batteries

16V lithium batteries weigh just 25-35% of their lead-acid counterparts, allowing weight savings of up to 30-45 pounds (13-20 kg) per single battery.

Now, since race cars are all about more power for smaller weight, imagine how much carbon fibers and titanium must be used to ensure savings of up to 30-45 pounds and how much that cost?!

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Anyway, 16 lithium batteries are based on the Lithium Iron Phosphate (LiFePO4) chemistry and feature 5 (five) 3.2V cells connected in series for a total of 16V.

Lithium batteries feature an internal Battery Management System (BMS) that monitors the battery charging and discharging parameters and protects the battery from unwanted events, increasing safety and prolonging the operating lifetime.

Also, lithium batteries operate in any position, even upside down. They are spill-proof and maintenance-free, and environmentally friendly since they contain no acid or heavy metals like lead, cadmium, mercury, and similar.

When compared with lead-acid batteries, lithium batteries offer many benefits, including weight savings, a much larger number of charging/discharging cycles (8-10x), no capacity loss due to large discharge currents, they accept charge much faster, etc.

However, lithium batteries should NOT be connected in parallel to increase their capacity or cranking Amps unless explicitly allowed by their manufacturer.

16V Battery Chargers

16V batteries must be recharged either by using vehicle alternators with 16V charge controllers or using 16V battery chargers.

To prolong the battery's lifetime, the use of intelligent, microprocessor-controlled chargers is recommended. Such chargers feature dedicated 16V AGM and/or 16V Lithium charging modes, they analyze the battery before charging and adjust the charging according to the battery condition.

noco genius gs26000

Most 16V advanced battery chargers also support charging 12V and 24V batteries and are a smart investment.

When dimensioning the chargers, keep in mind that good AGM batteries can be completely recharged in 5-6 hours, while most lithium batteries can be recharged in 2-3 hours easily, with many models supporting 1C charging currents.

16V Batteries Frequently Asked Questions (FAQ)

Here are some of the most common Frequently Asked Questions (FAQ) about 16V batteries:

What are 16-volt batteries used for?

16V batteries are used in race cars, close-track cars, drag racers, and similar vehicles.

Why do race cars use a 16-volt battery?

16V electric systems allow users to use plenty of 12V parts, at the same time increasing the performances of the electric systems and reducing the overall weight.

Note: before using 12V parts in 16V electric system, verify with their manufacturer if they are compatible with such voltage, just in case.

How many volts should a 16v battery have?

A fully charged AGM lead-acid battery should have 16.9-17.1 volts, while a lithium LiFePO4 battery should have 16.8-16.9 volts.

Since these values may vary slightly, check the documentation that came with the battery.

When the batteries are being charged, they are charged using higher voltages, typically ~18.3-19.2V (AGM lead-acid batteries) and 17.4-17.8V (LiFePO4 16V batteries).

Can you charge a 12-volt battery with 16 volts?

No, charging a 12V lead-acid battery with 16V will damage the lead-acid battery.

When charging a 12V lithium battery with 16V, the built-in BMS will disconnect the battery to protect it from the damage caused by overvoltage.

Is there a battery better than a lithium battery?

In terms of weight savings, at the moment, there is no commercial, off-the-shelf battery that is lighter than a lithium battery.

However, if You need a power source lighter than a lithium battery that is used only for cranking and stores enough energy for just a few cranks, supercapacitors can be used instead of lithium batteries. But, after cranking the engine, they can't be used to power onboard electronics, fans, pumps, etc.

In most situations, supercapacitors are used in combination with batteries.

Can You put a 16V battery in the car?

No, putting a 16V battery in the car should NOT be done without large modifications to the car's electric system. Swapping a 12V battery with a 16V battery without properly modifying the car's electric system will damage the car's electronics, electrics, and probably the 16V battery ...

turbostart s16v battery

Few Final Words

16V electric systems ensure many benefits for racing cars and other vehicles, but they also increase the load on individual components.

Thus, most cars, boats, and RVs still use 12V electric systems, while light industrial vehicles and golf carts use 12V, 24V, 36V, and higher voltages.

The main benefits of 16V batteries for racing cars are weight savings and thus money savings, and increased performances.